Reference

NBS

Publications AlllDb M 3 1 fl 7 7

NBSIR 82-2490 (NBS)

An Introduction to

Chemiluminescence Methods for

Lubricant Oxidation Studies

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Measurement Laboratory

Center for Materials Science

Materials Chemistry Division

Washington, DC 20234

April 1982

Interim Report for Period

March 19, 1981 -March 31, 1982

Prepared for U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

jjp

} of Recycled Materials

100

,1156

62-2490

1982

ded Oil Program

ington, DC 20234

national buhbau

OF 8TANDARDS

LIBRARY NBSIR 82-2490 (NBS)

AN INTRODUCTION TO

CHEMILUMINESCENCE METHODS FOR

LUBRICANT OXIDATION STUDIES

MAY 14 1982

D.B. Clark, S.J. Weeks, and S.M. Hsu

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Measurement Laboratory

Center for Materials Science

Materials Chemistry Division

Washington, DC 20234

April 1 982

Interim Report for Period

March 19, 1981-March 31, 1982

Prepared for U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Office of Recycled Materials

Recycled Oil Program

Washington, DC 20234

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director
• Izmiri

& M A*n: •, vac.aSfj

see!' f* i

'
An Introduction to Chemiluminescence Methods for Lubricant

Oxidation Studies

D. B. Clark, S. J. Weeks, and S. M. Hsu

Materials Chemistry Division

Center for Materials Science

National Bureau of Standards

Washington, D.C. 20234

1. Introduction

Chemiluminescence (CL), light produced as a result of a chemical reaction

is a valuable but under-utilized tool for the study of oxidation of fuels and

lubricants. Although a large amount of CL research has been conducted on

simple hydrocarbon systems, the extension of that work to complex mixtures,

such as lubricating oils, has been slow and rather limited.

Hydrocarbon oxidation produces chemiluminescence in the principal termina

tion reaction, recombination of peroxy radicals. The light intensity is

proportional to the rate of that reaction and can be related through various

methods to many of the other kinetic parameters of the overall oxidation

reaction scheme. CL measurement is a sensitive, non-intrusive method that can

provide a continuous monitoring of the reaction. These advantages can be

extremely valuable over conventional methods for theoretical and practical

studi es

.

This review will focus primarily on the application of CL in the study of

fuel and lubricant oxidation, an area of significant practical importance. A

brief discussion of the origin and mechanism of CL in hydrocarbon oxidation

will be followed by a summary of some of the methods which have been developed

for the determination of various kinetic parameters. This will be followed by

a review of the instrumentation and the applications that relate to fuel and

lubricant oxidation studies.

1
Several reviews [1-15] on the general topics of chemiluminescence are

listed in Table 1. Hydrocarbon oxidation is covered in references [9] and

[16].

2. Mechanism

The source of chemiluminescence in hydrocarbon oxidation is fairly well

established, although the exact mechanism is not completely understood.

Hydrocarbon oxidation occurs in a chain reaction generally following the

simplified scheme shown below:

Initiation RH — R* (1)

( R* + °2 (2)

Propagation L. R°2 * + RH - > ROOH + R. (3)

Branching ROOH > RO* + *0H (4)

|

R ' + R* -> products (5)

Termination / R0

2

* + R* > products (6)

( R0

2

* + ro

2

- products (7)

Where RH is the hydrocarbon, and R* and R0

2

* are the alkyl and peroxy radicals,

respectively.

Chemiluminescence is believed to arise from reaction (7), the recombination

or di sproporti onati on of peroxy radicals [14,17] by the Russell termination

reaction. This is the only reaction of the set that has sufficient energy to

emit visible light. The reaction can be written in more detail as:

R0

2

- + R0

2

- 4 RO* + ROH + 0

2

, (7a)

where the products are an excited state ketone RO*, an alcohol ROH, and molecular

oxygen. The excited state ketone can relax to the ground state with the emission

of light producing chemiluminescence,

2
RO* -> RO + hv. ( 8 )

The emission spectrum is equivalent to the fluorescence spectrum of the molecule.

The effective quantum efficiency for light emission is generally quite low,

on the order of 10 ^ to 10

^

[18]. This low yield is an effect of the low

luminescence efficiency and may also be due in part to a low excitation efficiency in reaction (7), [19,20]. The low luminescence efficiency is caused by

deactivation of the excited species by subsequent secondary physical processes

such as i ntermol ecul ar energy transfer and colli si onal quenching by oxygen or

other solution components,

RO* + M > RO + M* (9)

M* > M

where M is the quenching component, as well as by radiationless i ntramol ecul ar

transitions

,

RO* > RO . (10)

The apparent efficiency is also affected by absorption of the light by the

reaction mixture. These secondary physical effects and the excitation and

emission processes are discussed in greater detail in several reviews [3,4,13].

The intensity of chemiluminescence measured in photons per unit time is

proportional to the rate of reaction (7), w^ , or equivalently through the rate

2 equation to the square of the peroxy radical concentration [R0

? -] ,

-d[R0

?

• ] ?

T CL

“ C lw

7 dt

k 7

[ R0 2*J

3
The proportionality constant Cp essentially equal to the effective quantum

efficiency for emission, is in general unknown and unmeasurable, except in the

case of simple hydrocarbon systems [14]. In complex systems, the proporti onal i ty

constant will vary with the composition and concentration of the reactants since

the rate constant and excitation efficiency of reaction (7) depend strongly on

the structure of the two combining peroxy radicals [21,22]. It will also vary

with the composition of the entire system, reactants, products, solvents,

dissolved gases, etc., since any of these can influence the secondary physical

processes that lead to de-excitation without light emission. Thus, the reaction

rate or peroxy radical concentration cannot be determined quantitatively directly

from the light intensity. However, these and several other important kinetic

parameters can be determined from relative values of light intensity by some

of the methods described in the next section.

The effective quantum efficiency can be improved by adding energy acceptors

to the reaction mixture. These are substances to which the excited state

reaction products can efficiently transfer energy, and which have a higher

quantum efficiency for subsequent emission of light. This process, known as

sensitized luminescence, is described by the following reactions:

RO* + A > RO + A* (12)

A* > A + hv (13)

where A is the acceptor molecule. In general, the acceptor molecule is less

sensitive to quenching because it has a much shorter radiative lifetime than

the original excited species. The observed emission spectrum will be shifted

to that of the energy acceptor. To be effective, the acceptor must not otherwise participate in the reaction. Vasil 1 ev and co-workers have studied the use

of anthracene derivatives which are commonly used energy acceptors and divided

them into "good" and "bad" groups [23].

4
3. Kinetic Methods

Chemiluminescence measurements can provide valuable information about hydrocarbon oxidation reactions. However, two important points must be kept in mind

in evaluating experimental results [15,18]. First, the CL intensity is proportional

only to the rate of peroxy radical recombination, reaction (7), and not necessarily

to the overall oxidation rate. Second, CL occurs in two stages, excitation and

emission, and the efficiency or yield for each of these steps depends on the

composition of the reaction mixture. The effective quantum efficiency is, thus,

a complex function of composition so that comparisons between samples are not

necessarily straightforward. The brightest CL intensity is not necessarily

indicative of the fastest oxidation.

This complexity has made empirical approaches popular in chemiluminescence

studies of fuels and oils. Several easily measured parameters have been used

to compare oils in terms of oxidizability. Probably the least valid, in terms

of the above discussion, is a measure of the total intensity of light under

the same reaction conditions. More accurate measures are induction time at

a constant temperature or onset temperature during a slow temperature scan. In

these cases, CL is used basically as a marker for the beginning of significant

oxidation rather than as a direct measure of the oxidation rate. The induction

time has been used, for example, to rate oxidation inhibitors [24],

A number of more exact methods have been developed for using CL measurements to determine various kinetic parameters of oxidation in simple hydrocarbon

systems. The assumptions inherent in these methods are that the reactions

are described fairly completely by the scheme shown above and that CL arises

from reaction (7) of that scheme. While they were developed for simple hydrocarbons, some of these methods may be applicable to fuels and oils, especially

those methods carried out under steady state conditions.

5
In the development of many of these methods, the reactions were run with

added initiators. Although this is not necessary, it allows more information

to be determined, because the initiation rate is then known. Energy acceptor

molecules can also improve the measurements by increasing the sensitivity due

to increased light output and by minimizing secondary energy transfer processes

which may be composition and temperature sensitive.

Some of the methods are described below and are summarized in Table 2. The

rate constants refer to the reactions in the original sequence (1 to 7). General

references for the methods are given after each heading.

3.1 Activation Energy [7,14]

The temperature dependence of the CL intensity can be plotted in Arrhenius

fashion to give the activation energies for various of the reaction steps.

Mendenhall [7] shows that under steady-state conditions when oxygen diffusion is

rate limiting, a common situation in lubricant studies at high temperatures

,

the activation energy determined from the CL intensity E^ gives the activation

energies for the propagation and termination steps,

or

E r( = 2E

CL prop

E = E ri /2

prop CL

'term (14)

(15)

since the activation energy for termination by radical recombination is

essentially zero [15]. Under similar conditions, the activation energy for

initiation is given by Arrhenius treatment of U , the time to reach half of the

'z steady state intensity after the start of oxidation, as shown in Figure 1.

Under steady state conditions in the presence of sufficient oxygen the

initiation and termination rates are equal and termination is essentially all

by reaction (7). The CL intensity is then proportional to the initiation rate

as well as to the termination rate. Since the activation energy for termination is zero on Arrhenius plot of log CL intensity versus the reciprocal of

6
the absolute temperature then gives the activation energy for the initiation

directly [14]. The oxygen supply will be sufficient, that is, not rate

limiting, at low temperatures where the reaction rates are slower than the

oxygen diffusion rate or in an apparatus designed for optimum diffusion at

higher temperatures.

These measurements are more accurate with the use of an energy acceptor

because the effect of the temperature dependence of quenching and secondary

reactins is greatly reduced [14].

3.2 Oxygen Drop [8,14]

The oxygen drop method provides a measure of the overall oxidation rate.

This method is illustrated by Figure 1, a curve of CL intensity versus time.

Following the initiation of oxidation at point A the intensity increases to reach

a maximum value at B. At point C the oxygen is shut off and the intensity again

increases because of a decrease in quenching of the excited state species by

the now decreasing amount of oxygen in the system. The reaction rate, however,

is essentially independent of oxygen concentration except at very low levels

[8,16] and continues at a constant value to D. At D the oxygen in the system

has been consumed and the reaction rate and CL intensity drop sharply. This is

the "oxygen drop." If the amount of oxygen in the system at point C is known

then the time to the oxygen drop gives a direct measure of the oxidation rate.

Since the CL intensity is used only as a marker for the end of oxidation, the

method is unaffected by secondary physical processes such as quenching and energy

transfer. Its accuracy is primarily dependent on the quality of thermostatting

in the system [14].

7
It can be shown that [14]

1/t = a[RH] + p,

/w . \

35

a ” k

3 ]

t0

2

] 0’ (16)

P = C

2w

i /[0

2

] Q

,

where t is the oxygen drop-time, [RH] and [0

2 ]q are the hydrocarbon and initial

oxygen concentrations, w^. is the initiation rate, and C

2 is a constant whose

value depends on the initiator used. Repetition of the experiment at different

hydrocarbon concentrations and plotting the reciprocal of the oxygen drop time,

1/t, versus concentration gives the rate constant ratio k^/k^ , and either the

initial oxygen concentration or the initiation rate again providing one of those

quantities is known. A further extension of the method allows very precise CL

measurements of the slope of the oxygen drop to be used to calculate the rate

1/2 constant ratio k^k^ [25].

As originally developed, the oxygen drop method was used in single phase

systems, where the only oxygen available was that dissolved in the liquid phase.

This could be extended to two-phase liquid-gas systems provided the mass transfer

between the phases was not limiting. A system of this type, i ncorporati ng both

CL and independent measurements of oxygen consumption, is being developed at the

National Bureau of Standards.

3.3 Non-Steady State Methods [12,26,27]

The above methods imply stationary or steady state reaction kinetics and,

in general, give only ratios of rate constants. Absolute values of the rate

constants can be obtained by suddenly causing the reaction to enter into a

non-stati onary state by, for instance, a sudden change in the initiation rate or

sudden introduction of oxygen into a chemically initiated system. Changing the

8
initiation rate, which can be done by fast introduction of an initiator or abruptly

starting or stopping the illumination of a photosensitive initiator, gives k j

the

termination reaction rate constant. Sudden introduction of oxygen into a

system containing hydrocarbon and an initiator gives both k,- and k^ termination

rate constants, since the introduction of oxygen causes a change in termination

from reaction (5) to reaction (7). This is also called the oxygen aftereffect

method. Rapid heating of the sample has also been studied as a method of inducing

non-stationary kinetics [12].

These non-stationary state methods are primarily for use with simple hydrocarbon systems. They may not be applicable to oils or other complex mixtures,

since they depend on the rate constants of the six individual reactions not

changing with reaction conditions. In a complex mixture, the observed rate

constant is an average of the individual rate constants for each hydrocarbon

in each step and is a function of composition which will, in general, change

with changing reaction conditions.

4. Applications

The potential applications of CL far exceed the number and type of

current applications. Because of the sensitivity of the technique and the

possibility of relating the CL signals to the chemistry and kinetics of the

system involved, CL can be used to evaluate the stability and oxidative capacity

of fuels and lubricants in terms of: (1) molecular structural differences,

chemical composition, and basestock source; (2) physical properties, such as

distillate cut (boiling point range) and viscosity grade; (3) effect of additives

and additive type; (4) additive interactions with basestocks and with other

additives; (5) formulation of additive packages; (6) effect of processing changes;

(7) effect of environment ( temperature , atmosphere, contact with other materials,

etc.); (8) service life/performance; (9) storage life; and, (10) quality control

of processing.

9
All of the above focus on the oxidation degradation and reaction mechanisms

and allow products to be evaluated from the point of view of their stability

(degradation) and performance (failure). In addition, insights into oxidation

mechanisms gained in these experiments can be extremely useful in new additive

research and in process technology development.

Highlights of the few published or known studies of chemiluminescence in

the oxidation of actual fuels and lubricants are presented in Table 3 and will

be discussed below. Related basic research on chemiluminescence in simple

hydrocarbon systems is summarized in Table 4. Chemiluminescence is particularly

useful in studies of oxidation inhibitors and catalysts, both of which will be

discussed in later sections.

4.1 Fuel and Lubricant Studies

The published studies of CL in the oxidation of actual fuels and lubricants

are limited to three groups. Two groups in the USSR investigated antioxidants

in oils and a group in the U.S. studied fuel stability.

Anti oxi dant Studi es . In the USSR, Suleimanova and co-workers [28-33]

studied the oxidation stability of paraffin oils and lubricating oil basestocks

with and without additives. They developed two standard test procedures [30],

a "constant background method" in which the time to reach a constant CL

intensity was determined at each temperature during stepwise heating from 100

to 200 °C in 10° steps, and a "constant time method" in which the total CL

signal was measured for 10 s for each temperature step as before. These

methods were used primarily as relative analytical techniques rather than as

actual oxidation tests. For instance, the authors observe that light output

from oxidized oils is decreased compared to that from fresh samples. They,

therefore, use their procedures to judge the degree of oxidation or degradation

of oil samples from standard bench oxidation tests [32] or engine tests [31].

10
This work can be used to illustrate some of the factors that must be

considered in developing evaluative CL test methods. The constant background

test is basically a measurement of induction time as a function of temperature.

3

However, when a single 0.2 cm sample volume is used for the entire test, the

measurements toward the end of the run are being made on a severely oxidized

sample. The authors reported that by the end of the tests (6 to 14 hours) the

oils had been reduced to powders [31].

The constant time method is a much shorter test lasting only 10 s at each

temperature and therefore does not suffer this drawback. Because of its short

duration it is the only method of the two used routinely in these studies. The

method essentially measures an initial reaction rate and its variation with

temperature. The authors used this initial rate method to rank the antioxidant

performance of various additives, the lower the light output, the better the

additive. However, in the work discussed below, Gol'denberg, Shmulovich, and

Yurchenko [39], show that other factors are also important in judging additive

effectiveness. The usefulness of these two methods is unknown since Suleimanova

presents rankings of several tested additives without comparable data from other

tests to support his methods or conclusions [33].

The authors also use both of these methods to rank the oxidative stability

of a number of basestocks [30,33]. This could also lead to inaccurate results

because, as discussed before, CL intensities should not be used as direct

measures of oxidation rates [12,14,18]. CL measuremenets should only be used to

determine other parameters such as reaction rates, induction times, or activation

energies which can then be used for comparison. In general, the CL intensity

is proportional only to the rate of the reaction from which the light is produced,

not necessarily to the overall oxidation rate [15,18]. The proportional i ty

constant is the product of the efficiencies of excitation and emission, both

11
of which depend on the sample composition and experimental conditions. For

example, lubrication oil basestocks with different physical properties may

contain widely different oxygen concentrations in a given oxidation apparatus

(especially in tests not designed for optimum control of oxygen diffusion into

the sample). As shown before in the discussion of the oxygen drop test, the

light emission is very sensitive to oxygen concentration.

Shmulovich and Gol'denberg [24] studied chemically and thermally

initiated CL in paraffin oils over a temperature range from 60 to 190 °C.

Generally, azobi si sobutyroni tri 1 e (AIBN) or a hydroperoxide was introduced into

the system to initiate RO^- formation. Dibromoanthracene (DBA) was used as an

energy acceptor to enhance the CL signal. A number of different compounds were

studied for their antioxidant capabilities. Natural antioxidant concentration

and thermal stability of the oils could be determined by measuring the induction

period, the time from the beginning of a test to the appearance of a significant

increase in the CL signal. This test was used to rate antioxidants and provided

a rapid screening procedure for antioxidant efficiency. The efficiency of a

given antioxidant was calculated from an empirical relationship comparing the

antioxidant induction time as a function of concentration with that of another

antioxidant which had been chosen as a standard. One study roughly correlated

the oxidation rate with activity of antioxidants. According to the authors,

these studies showed the CL signal had two components: one due to peroxy radical

recombination and the other resulting from accumulation of hydroperoxide reaction

products. However, this hypothesis is not generally supported by other investigators [17].

Gol'denberg and Shmulovich later extended this work [37-39], incorporating

the theory of Karpukhin and Shlyapintokh [8,34-36] which is discussed in Sec-

• / ^ tion 4.3. Using this theory the authors were able to calculate the ratio kg/k -j~

12
where kg [see reaction (18)] and are the rate constants for termination by

interaction of peroxy radicals with inhibitors and by di sproportionati on

respectively. This ratio was used as a ranking parameter to rate the effectiveness of a number of antioxidants and to determine the concentration of

naturally occurring inhibitors. The authors also suggested the possibility of

effecting long-term stabilization of oil by using CL measurements to control

subsequent antioxidant addition in service.

Fuel Stabi 1 i ty . Mendenhall and Nathan [40-42] at Battelle, were able to

predict the service life of JP5 jet fuels using the oxygen drop CL method. A

set of vs t curves, at temperatures between 125 and 150 °C were obtained.

The maximum intensity (I max

in Figure 1) and induction period (t^ in Figure 1)

from such temperature variation experiments were used to obtain activation

energies from Arrhenius plots. The plots showed that two different propagation

mechanisms were occurring, each with its own temperature regime. These results

explained why the commonly used accelerated tests did not give accurate indications of fuel stability. The major benefit of CL techniques is that due to

their extreme sensitivity they can examine materials under actual use conditions

in non-accel erated tests. Several jet fuels were evaluated by the CL techniques. "Bad" fuels were able to be discriminated from "good" fuels.

In an isolated study, Markby and co-workers [43] at the U.S. Bureau of Mines,

observed light induced CL of coal derivatives and petroleum asphalts while

performing a liquid scintillation experiment. They report their observations

and suggest a mechanism for photo- i ni ti ated chemiluminescence.

4.2 Simple Hydrocarbons

Because of the complexity of real samples, it may be difficult or impossible

to accurately extrapolate methods and mechanisms from simple chemical systems.

Although quantitative data on individual rate constants cannot be obtained due

13
to the multiplicity of reactions and deactivations that can occur; overall

rates and other qualitative information can provide much necessary information,

as noted above. Basic research studies can provide a better understanding of

real situations by elucidating simple mechanisms that combine to form the

complex system. Most of the knowledge of the chemiluminescence process that

has been described above has been determined from studies of simple systems.

These studies are listed in Table 4. They will not be discussed individually,

but many of them have been used in the general discussions of CL in this paper.

4.3 Oxidation Inhibitors

Chemiluminescence appears to be a valuable tool for the study of oxidation

inhibitors. In general, inhibitors work by reacting with radicals to terminate

growing chains and, thus, slow the rate of oxidation. Since the CL intensity

is a measure of peroxy radical concentration, inhibitor addition diminishes

the intensity in direct proportion to the activity of the inhibitor. At steadystate, the following relation between the oxidation rate, w, and the CL

intensity, I, can be obtained,

where the subscript, 0, refers to the uninhibited system [34].

The following set of equations describes the action of an inhibitor and

must be added to the previous set, Eqs. (1-7), to complete the reaction scheme

for inhibited oxidation:

InH + RO^- — R00H + In- , (18)

RO^- + Inkg

7

> products , (19)

2 In-

^10

t* products

,

(20)

14
where InH is the inhibitor.

Karpukhin, Shlyapi ntokh , and co-workers [8,34-36] used this scheme in

studying the kinetics of inhibited oxidation in several simple hydrocarbon

systems. They showed and confirmed experimentally that to a very good approximati on

where [ I nH ]q

i ni ti ati on.

(»' ko[ 1 nH] = 1 + L1 ^k 7

w.)

( 21 )

is the initial inhibitor concentration, and w. is the rate of

The parameter kg/(kyW .)

2 is found from a plot of (I

q /I) 2 versus

[ I nH

]

Q

.

Another parameter, k Q (w./k-,) 2

, found from the slope of the kinetic curve of

I/Iq versus time, can be combined with this to give individual values for the

initiation rate, w., and the rate constant ratio k 0 /(k-,)

2

, which is characteri sti

c

of the relative activity of the inhibitor. The kinetic curves which show an

increase in intensity as the inhibitor is consumed, are S-shaped with the

inflection point at I/Iq = 0.55 [25]. The slope at that point is related to

this second parameter by [35]:

d(I/I

0

) dt max

= 0.22 k 8

( 22 )

Use of this method was complicated by the observation that the maximum

slope decreases with increasing initial concentration of inhibitor implying

a decrease in inhibitor activity with increasing initial concentration. This

result, supported by other investigators [44], is suggested as being due to an

effect of inhibitor reaction products on the radical concentration [36], perhaps

branching due to breaking of peroxide bonds in some of the products. To

15
surmount this problem, the data for a number of different initial concentrations

were extrapolated to [InH]g = 0 to give a concentration independent value for

d(I/I n )/dt for use in the above equation.

Several application-oriented studies have used CL as a convenient

means for rating the relative effectiveness and concentration dependence of

initiators. Shlyapintokh [45], using Eq. (17) above, suggested using the

reciprocal of the inhibitor concentration that gives a fifty percent decrease

in CL intensity as a measure of relative activity. In studies already discussed,

Suleimanova and co-workers [28-33] ranked additives by their ability to decrease

the absolute CL intensity in a given oil. Shmulovich and Gol'denberg [24]

initially used the induction time to rate additives but later extended

k

Karpukhin and Shlyapi ntokh 1 s theory to these complex materials using kg/(ky) 2

as a ranking parameter [39].

The inhibitor concentration dependence can also be used to determine

the number of chains terminated per molecule of inhibitor and to investigate

mechanisms of inhibitor action. Examples of the latter are studies which

show that stable nitroxyl radicals terminate chains by reacting only with

alkyl radicals and not with peroxy radicals [46], while other inhibitors, like

ionol, react exclusively with peroxy radicals. Other studies have looked at

synergistic effects from combinations of inhibitors [30].

One final concern in using CL to study inhibition is that some antioxidants,

such as phenols, are known deactivators of excited states so that the decrease

in CL intensity could also be due to quenching of the excited species. However,

Vasil ' ev [47] and others [8] have shown that the quenching effect is negligible

in comparison with inhibition.

16
4.4 Metal Catalysts

CL is also applicable to studies of catalyzed reactions. However, only a

few CL studies of catalyzed hydrocarbon oxidations have been published. Zakharov

and Shlyapintokh [48-50] studied the oxidation of ethylbenzene in the presence

of cobalt acetate, which catalyzes the reaction by decomposing hydroperoxi des

to form new radicals. Catalysis increased the steady-state CL intensity above

that of the non-catalyzed reaction; but, except at fairly low concentrations,

the intensity was independent of the amount of catalyst. The authors showed

that in a system where initiation occurs only by the catalyzed hydroperoxi de

decomposition, the CL intensity is proportional to the hydroperoxi de concentration and decomposition rate, as well as to the oxidation rate [49]. This

allowed measurement of the effective rate constant for decomposition [50] and

determination of the mechanism of catalyst action [48] by using non-stationary

state techniques. The results agreed very well with a contemporary study of

the same reaction by standard methods.

Gol'dberg and Obukhova [51] studied the reaction of manganese stearate

with peroxy radicals. Such transition metal salts apparently act as inhibitors

under certain conditions [16,52] by donating an electron to a peroxy radical,

eliminating the radical, and terminating an oxidation chain. The authors used

CL techniques to determine the rate constant for the reaction and showed that

the value was close to correspondi ng values for the reaction of peroxy radicals

with strong inhibitors.

Rychl a-Mati sova and co-workers [53] studied CL in the decomposition of

2 ,2-azobi si sobutyroni tri 1 e (AIBN) and cumene hydroperoxide catalyzed by

bi s(- )-ephedri ne copper(II) chelate. With AIBN, a commonly used initiator, the

copper chelate acts to terminate radicals formed from the initiator, with a

resulting decrease in CL. With the hydroperoxi de , the chelate acts as an

17
accelerator, catalyzing decomposition to form new radicals. This causes an

increase in CL. In a real oxidation system, a metal catalyst probably plays

both roles, inhibitor and accelerator. The overall effect can be detected and

followed by measuring changes in the CL intensity.

5. Instrumentation

The basic instrumentation used for CL is spectroscopically quite simple.

General reviews [2,7,10,11] of CL instrumentation are listed in Table 1.

Figure 2 shows block diagrams of a typical instrumental arrangement. The typical

instrument consists of a heated reaction cell in a thermally insulated and lighttight environment. The light emitted due to the oxidation reaction may or may

not be spectrally isolated by filters, monochromators, polychromators , or simply

by the transmission characteri sties of the optics. The light is then detected by

a PMT, which may be cooled to decrease the dark noise. The PMT is a phototransducer, whose electrical output can be monitored using an electrometer or photon

counter. The signal can then be displayed on a recorder, oscilloscope, or CRT,

or may be processed digitally. Commercial instruments are available for bioluminescence studies. However, these would have to be modified for the study of

fuels and lubricants. In general, the CL apparatus consists of a special

reaction cell combined with a spectrometer or filter photometer. Liquid scintillation counters, spectrofl uori meters , filter f 1 uorimeters , UV-vis spectrophotometers, photometers, and radiometers have all been modified (or assembled) for

use in CL studies. The main instrumental criteria for the study of the weak CL

emitted in the oxidation reactions of fuels and lubricants are: (1) a reaction

cell with a viewing port; (2) accurate temperature measurement and control;

(3) accurate control of atmosphere and gas ( 0

^ ) introduction to the sample;

(4) a "light-tight" optical path; and (5) a sensitive photomultiplier tube (PMT).

18
State-of-the-art instrumentation has to consider the reaction cell

separately from the spectral readout device. Engine temperatures to which a

lubricating oil is subject are as high as 200 to 300 °C. No commercially

available cells are made to study condensed phase CL at these high temperatures

.

However, there are articles [54,55] which describe experimental and theoretical

considerations of cell design in analytical chemiluminescence systems. Currently,

most researchers use quartz or glass reaction vessels.

Spectrometri cal ly , the most recent innovations consist of the use of

image devices, such as photodiode arrays and vidicon tubes or the use of

rapid-scan or slew-scan spectrometers . The obvious advantage here is the

ability to get much more detailed information on the oxidation reactions

occurring. Ingle and co-workers [56,57] have utilized a mi croprocessorcontrolled intensified diode array to acquire CL spectra. This system is

capable of producing a 512 point CL spectrum from 200 to 840 nm in as little as

four milliseconds and can also signal average. The primary disadvantage of

image devices is their lack of sensitivity when compared to PMT. Although the

CL spectra obtained provide principally qualitative information about the CL

reactions, they are useful for (1) choosing PMT 1 s for maximum sensitivity at

the wavelengths of maximum CL intensity, (2) identifying reactant or production

absorption i nterferences , (3) elucidating the nature of matrix interferences,

or (4) obtaining information about CL reaction mechanisms (e.g., identification

of the luminescing species or the change in the species luminescing with time

or temperature). Often qualitative information may be sufficient to solve a

problem or control a process. The provision of corrected CL spectrum may in

itself provide necessary information.

The CL signal is usually assumed to come from the bulk of the solution

(homogeneous CL) and not to change its spectral distribution. Lloyd and coworkers [59-61] observed a comparatively strong CL from the reaction(s) occurring

19
at the walls of the reaction vessels (heterogeneous CL) which could easily be

mistaken for CL from the bulk of the solution. They noted that the CL intensities did not vary with volume but did vary with the method used to clean the

reaction vessel. The heterogeneous CL was in a different part of the spectrum

than the homogeneous CL and could be minimized under certain conditions.

Monitoring the entire spectrum would help to aleviate this problem and also give

added insight into changes in reaction types occurring. Often to avoid changes

in spectral information, an energy transfer agent will be used. This does not

affect the overall oxidation reaction but does enhance the CL and limit the CL

light output to a specific portion of the spectrum.

In CL studies of fuels and lubricants temperature control, varnish formation, condensation, correct identification of spectral information (e.g., bulk

vs surface reaction, or stray light, or changes in spectral composition), and

safety are important. Oscillations of the CL intensity have been observed [58]

which corresponded to the change in direction of the temperature gradient

between the sample and thermostatting equipment. The oscillations were substantially larger than would have been expected if they were solely due to temperature fluctuations. This demonstrates the need for accurate temperature control.

Varnish formation is difficult to avoid, and viewing from the bottom of a cell

should be done very cautiously. Proper gas flows to control the atmosphere can

eliminate condensation along the optical path.

6. Conclusion

Chemiluminescence methods provide an extremely practical means of testing

the stability of fuels and lubricants, as well as of selecting additives and

studying the oxidation process under conditions similar to those experienced in

service. CL methods are nonintrusive and can provide continuous monitoring. The

techniques are sensitive so that analyses are rapid, and only require a small

20
sample. At present, however, the lack

cells hinders the technique's use as a

instrument would be a powerful tool to

lubricant oxidation.

of suitable, commercially available sample

routine research tool. A wel 1 -designed CL

attack the complex problems of fuel and

21
References

[1] Gundermann, K. D. , " Recent advances in research on the chemiluminescence of

organic compounds," Topics i_n Current Chemi stry , 46, (Photochemistry),

Spri nger-Verl ag , New York, 1974.

[2] Heller, C. A., and Richter, H. P. , " Chemiluminescence in the condensed phase

Measurement of rates and yields of excited state formation," Chapter 1 in

Creation and Detecti on of the Exci ted State , Vol. 3, W. R. Ware, ed.

Marcel Dekker, NY (1974).

[3] Hercules, D. M. , "Physical Basis of Chemiluminescence," in Current Status

of Li qui d Sci nti 1 1 at ion Counti ng , " F. D. Bransome, ed. , NY (1970).

[4] McCapra, F. , "Chemiluminescence of organic compounds," Prog, in Org. Chem.

8, 231 (1973).

[5] McCapra, F. , "Chemiluminescence," Essays in Chemistry , 3, 101 (1972).

[6] McCapra, F. , "The chemiluminescence of orqanic compounds," Pure and Appl.

Chem . , 24, 611 (1970).

[7] Mendenhall, G. D. , "Analytical applications of chemiluminescence," Angew . Chem . Int. Ed. Engl . , 16, 225-232 (1977).

[8] Papisova, V. I., Shlyapi ntokh , V. Ya. , and Vassil'ev, R. F. , "Chemiluminescence and the kinetics of chemical reactions," Uspekhi Khi mi

i

, 34, 599 (1965)

[9] Reich, L. , and Stivala, S. S. , Weak chemiluminescence during hydrocarbon

autoxi dati on , Ch. 5 in Autoxi dati on of Hydrocarbons and Polyol efi ns , Ki neti cs , and Mechani sms

,

Marcel Dekker, Inc. , NY (1969).

[10] Seitz, W. R. , and Neary, M. P. , "Chemiluminescence and Bioluminescence

Analysis," Ch. 2. in Contemporary Topics i n Analyti cal and Clinical

Chemi stry , Vol. 2, Plenum Press, NY (1977).

[11] Shlyapi ntol sh , V. Ya, Karpukhin, 0. N. , Postnikov, L. M. , Tsepalov, V. F.

,

Vi chuti nski i , A. A., and Zakharov, I. V., Chemiluminescence Techniques in

Chemical Reactions , Consultants Bureau Transl., Plenum Press, NY (1968).

[12] Shlyapi ntokh , V. Ya. , "Free radicals and chemiluminescence," Russ . Chem . Rev. , 35, 292 (1966).

[13] Vassil'ev, R. F. , "Chemiluminescence excitation mechanisms," Russ . Chem . Rev . 39, 529 (1970).

[14] Vassilev, R. F. , Chemiluminescence in Liquid-phase Reaction, Chapter 8 in

Progress i n Reacti on Ki neti cs , 4, G. Porter, ed. Pergamon Press (1967).

[15] Vassilev, R. F. , "Chemiluminescence in solutions," Sov. Phvs . Usp . , 9, 504

(1967).

[16] Emanuel, N. M. , Denisov, E. T. , andMaizus, Z. K. , Liquid-phase Oxidation

of Hydrocarbons , Plenum Press, NY (1967).
[17] Vassil'ev, R. F. , "On the mechanism of chemiluminescence in oxidation of

organic substances and polymers," Makr . Chem. , 126 , 231 (1969).

[18] Belyakov, V. A., and Vassil'ev, R. F. , "On some problems concerning investigation of liquid-phase chemiluminescence," Photochem . Photobi ol . , 6, 35 (1967).

[19] Kellogg, R. E. , "Mechanism of chemiluminescence from peroxy radicals," J. Am . Chem . Soc., 91, 5433 (1969).

[20]

Beutel , J. , "Chemiluminescence in oxidation reactions. The oxidation mechanism

of dimedone," J. Am. Chem. Soc. , 93, 2615 (1971).

[21] Howard, J. A. , and Ingold, K. V. , "The self-reaction of sec-butyl peroxy

radicals. Confirmation of the Russell mechanism," J. Am. Chem. Soc., 90,

1056 (1968).

[22] Howard, J. A., and Ingold, K. V., "Rate constants for the self-reactions of

n- and sec-butyl peroxy radicals and cycloperoxy radicals. The deuterium

isotope effect in the termination of secondary peroxy radicals," J. Am . Chem . Soc . , 90, 1058 (1968).

[23]

Vasil 'ev, R. F. , Vi chuti nski i , A. A., and Cherkasov, A. S. , "Chemiluminescence

activated by anthracene derivatives," Phys . Chem . , 149 , 203 (1963).

[24]

Shmulovich, V. G. , and Gol'denberg, V. I., "Chemiluminescence method for

studying thermal -oxi dati ve stability of petroleum oils," Chem. Technol.

Fuel Oils , 13, 669 (1977).

[25]

Vasil 'ev, R. F. , "Chemiluminescence kinetics and the study of reactions

involved in the liquid-phase oxidation of hydrocarbons , " Ooklady Akad. Nauk.

,

144, 143 (1962).

[26]

Vichuti nski i , A. A., "Chemiluminescence methods for determining the absolute

magnitude of the rate constants for the disappearance of peroxide radicals

in the liquid phase," Dokl ady Akad . Nauk . , 157 , 150 (1964).

[27]

Belyakov, V. A., and Rafikova, V. S. , "Determination by the method of

chemiluminescence of the rate constant of quadratic recombination of

peroxide radicals in reactions with a low luminescence yield," Bull. Akad.

Sci . USSR , 23, 2359 (1974).

[28] Suleimanova, L. G. , Suleimanova, F. G. , and Zikha, V. B. , "Different types of

additives for motor oils studied by a chemiluminescence method," Azerb . Khlm . Zh. , (2), 71-4 (1974).

[29] Suleimanova, L. G. , Suleimanova, F. G. , and Ziksha, V. B. , "Antioxidant

additives studied by chemiluminescence," Azerb. Khim. Zh. , (1) 62-5 (1973).

[30]

Kuliev, A. M. , Suleimanova, F. G. , Gurylev, G. G. , Ziksha, V. B.

,

Suleimanova, L. G. , and Abdullayev, A. M. , "(1) Radiation of oxidizability of

oils and oils with additives by a method of chemi 1 umi nescence. (2) Oxidizability of oils and oil additive studies by a chemiluminescent method," Lubri

eating Oil Additives, publ . by Acad. Sci., Azerb., SSR, (1) NTIS AD723 151,

(1971); (2) NTIS AD742 643, (1972).
[31] Kuliyev, A. M. , Suleimanova, F. G. , Gurylev, G. G. , Ziksha, V. B. Suleimanova, L. G. , and Abdullayev, A. M. , "Oxidizability of oils with

additives under engine working conditions by a chemiluminescence method,"

Pris . K. Smaz. Mash, No. 2, 173-179 (1969), NTIS AD721 035, (1971).

[32] Suleimanova, G. F. , Gurylev, G. G. , Ziksha, V. B. , Suleimanova, L. G.

,

and Abdullayev, A. M. , "Investigation of the action of organic acids on the

oxidizability of mineral oils by the chemiluminescence method," Azerb.

Neft . Khozy . , 47, 37-39 (1968), NTIS AD702 150, (1970).

[33] Suleimanova, G. F. , Gurylev, G. G. , Ziksha, V. B. , Suleimanova, L. G.

,

Abdullayev, B. I., and Abdullayev, A. M. , "Chemiluminescent method for

studying the thermal stability of motor oils with additives," Azerb. Neft.

Khozy , 47, 42-43 (1968), NTI AD700 374, (1969).

[34] Karpukhin, 0. N. , Shlyapi ntokh , V. Ya. , Zolotova, N. V., Kozlova, Z. G. , and Rusina, I. F. , "Mechanism of the weakening of chemiluminescence by

inhibitors of free-radical reactions," Zh. Fiz. Khim. , 37, 1636 (1963).

[35]

Karpukhin, 0. N. , Shlyapi ntokh , V. Ya. , and Zolotova, N. V., "Chemiluminescence

in inhibited oxidation reactions and the activity of inhibitors. Communication 1. Theory of chemiluminescent methods of finding the activity of

inhibitors," Izvest . Akad . Nauk. SSR , Ser. Khim, No. 10, 1718-1721 (1963).

[36] Karpukhin, 0. N. , Shlyapi ntokh , V. Ya. , and Zolotova, N. V., "Chemiluminescence

in inhibited oxidation reactions and the activity of inhibitors. Communication 2. Measuring the activity of inhibitors by chemiluminescence methods,"

Izvest . Akad . Nauk . SSR , Ser. Khim, No. 10, 1722-1727 (1963).

[37] Shmulovich, V. G. , and Gol'denberg, V. I., "Study of the antioxidant activity

of inhibitors of the oxidation of paraffin oil hydrocarbons," Neftekhimiya , 19, 912-20 (1979).

[38] Gol'denberg, V. I., and Shmulovich, V. G. , "Study of the mechanism of

chemiluminescence in the autoxidation of paraffin oil at elevated temperatures," Neftekhimiya , 19, 207-13 (1979).

[39] Gol'denberg, V. I., Shmulovich, V. G. , and Yurchenko, N. I., "Chemiluminescence methods of investigating inhibited oxidation of mineral oils and

fats," Petrol . Chem . USSR , 18, 166-174 (1979).

[40] Nathan, R. A., and Lundeen, G. W. , paper presented at VIII Inti. Conf.

Petrochem. , August 1975.

[41] Nathan, R. A., "Chemiluminescence for the determination of the kinetics and

mechanism of jet fuel oxidative degradation," Naval Air Systems Command,

Contract N00019-73-C-0360 , March 1974.

[42] Nathan, R. A., Mendenhall, G. D. , Hassell, J. A., and Wallace, J. D.

,

"Glowing analyses," Indus . Res. , Dec. 62 (1975).

[43]

Markby, R. E. , Friedel, R. A., Friedman, S. , and Sternberg, H. W. , "Lightinduced chemiluminescence in derivatives of coal and petroleum," Fuel , 49, 242 (1970).
[44] Howard, J. A., and Ingold, K. U. , "The inhibited autoxidation of styrene.

Part II. The relative inhibiting efficiencies of meta- and para-substituted

phenols," Can . J. Chem . , 41, 1744 (1963).

[45] Shlyapi ntokh , V. Ya. , Karpukhin, 0. N. , and Rusing, I. F. , "Determination of

the relative activities of antioxidants from the reduction in the intensity

of chemiluminescence," J. Gen '

1

. Chem . , 33, 3036 (1963).

[46] Khloplyankina, M. S. , Buchachenko, A. L. , Neiman, M. B. , and Vasil 'eva, A. G.

,

"On the mechanism of termination of chain oxidations by radical stabilizers,"

Ki neti ka i_ Katal iz . , 6, 394 (1965).

[47] Vasil 'ev, R. F. , and Vichutinski i , A. A., "Investigation of chemiluminescence

incident to oxidation reactions in the liquid phase," Inzvest. Akad. Nauk.

SSSR , Ser. Fiz. , 27, 729 (1963).

[48]

Zakharov, I. V., and Shlyapi ntokh , V. Ya. , "Chemiluminescence and mechanism

of the catalyzed decomposition of ethylbenzene hydroperoxide," Dokl . Akad . Nauk. SSSR, 150, 1069 (1963).

[49] Zakharov, I. V., and Shlyapi ntokh , V. Ya. , "Chemiluminescence in slow chemical

reactions I. Rule of chemiluminescence in the catalyzed oxidation of

ethylbenzene," Ki neti ka i_ Katal i z . , 4, 239 (1963).

[50] Zakharov, I. V., and Shlyapi ntokh , V. Ya. , "Chemiluminescence in slow chemical

reactions III. Chemiluminescence study of the kinetics of hydroperoxide

accumulation in the catalyzed oxidation of ethylbenzene," Kinetika i Kataliz.,

4, 706 (1963).

[51] Gol'dberg, V. M. , and Obukhova, L. K. , "On the high reactivity of peroxy

radicals in oxidation-reduction reactions," Dokl. Akad. Nauk. SSSR, 155,

860 (1965).

[52] Ingold, K. U. , "Inhibition of the autoxidation of organic substances in the

liquid phase," Chem . Rev. , 61, 563-589 (1961).

[53] Rychl a-Mati sova J. L. , Horanska V., and Barton, J. , "Chemiluminescence on decomposition of 2,2 azobi si sobutyroni tri 1 e and cumene hydroperoxi de in

the presence of bi s(-)-ephedri ne copper(II) chelate," J. Luminescence, 10,

129-136 (1975).

[54] Stieg, S. , and Nieman, T. A., "Experimental and theoretical considerations

of flow cell design in analytical chemiluminescence," Anal. Chem., 50. 401

(1978).

[55] Schroeder, H. R. , and Volgelhut, P. 0., "Flow system for sensitive and

reproducible chemiluminescence measurements," Anal . Chem. , 51, 1583 (1979).

[56]

Marino, D. F. , and Ingle, J. D. , Jr., "Mi crocomputer-control 1 ed intensified

diode array data acquisition system for chemiluminescence spectra," Anal.

Chem. , 53, 645 (1981).
[57] Ryan, M. A., Miller, R. J. , and Ingle, J. D. , Jr., "Intensified diode array

detector for molecular fluorescence and chemiluminescence measurements,"

Anal . Chem . , 50, 1771 (1978).

[58] Rychly, J. , Mati sova-Rychl a , L. , and Lazar, M. , "A 'heterogeneous' model

for oscillations of chemiluminescence in non-stationary oxidation of

hydrocarbons," J. Poly . Sen. , Symp. #57, 139 (1976).

[59] Lloyd, R. A., "Apparatus for studying thermal decomposition reactions and

observations on benzoyl peroxide in de-oxygenated benzene," Trans. Faraday

Soc. , 61, 2173 (1965).

[60] Lloyd, R. A., "Low level chemiluminescence from hydrocarbon anti oxi dati on reactions," Trans . Faraday Soc . , 61 , 2182 (1965).

[61] Bowen, E. J. , and Lloyd, R. A., "Chemiluminescence of organic peroxide

decomposition," Proc . Royal Soc . , A275 , 465 (1963).

[62] Belyakov, V. A., Vasil 'ev, R. F. , and Nalbandyan, D. M. , "Chemiluminescence

reactions of peroxides with armines in the presence of oxygen. I. Kinetics

of the reaction of dimethyl ani 1 i ne with di cvcl ohexydperoxy dicarbonate,"

Kim . Vysok . Enerq . , 10, 238-244 (1976).

[63] Vasil 'ev, R. F. , and Rusina, I. F. , "Mechanism of chemiluminescence in the

oxidation of organic substances in solution," Dokl. Akad. Nauk SSSR, 156,

1402 (1964).

[64] Vasil 'ev, R. F. , and Vichuti nski i , A. A., "Chemiluminescence and oxidation,"

Nature , 194, 1276 (1962).

[65] Vasil 'ev, R. F. , Karpukhin, 0. N. , and Shlyapi ntokh , V. Ya. , "Device for

measuring weak light fluxes," Zhur. Fiz. Khim. , 35 (1961); Russ. J. Phys. Chem.

35, 223 (1961).

[66] Vasil 'ev, R. F. , and Rusina, I. F. , "Oxygen quenching of excited states in

chemi 1 umi nescenci ng solutions," Dokl . Akad. Nauk SSSR , 153 , 1101 (1963).

[67] Vasil 'ev, R. F. , "Secondary processes in chemiluminescent solutions," Nature , 196, 668 (1962).

[68] Nathan, R. A., and Lundeen, G. W. , "Chemiluminescence for the determination

of activation energies of hydrocarbon oxidation," paper presented at the

8th International Photochemistry Conference, August, 1975.

[69] Lundeen, G. W. , and Adelman, A. H. , "Chemiluminescence of decomposition of

1,4 peroxy-1,4 dimethoxy-9 , 10 di phenyl anthracene , " J. Am. Chem . Soc . , 92,

3914 (1970).

[70] Lundeen, G. W. , and Livingston, R. , "Chemiluminescence of hydrocarbon oxidation," Photochem. and Photobi ol

.

, 4, 1085 (1965).

[71]

Mendenhall, G. D. , and Nixon, J. R. , "Chemiluminescence from thermal decomposition of 1-tetralin hydroperoxi de in N- tetradecane , " ACS Organi c Prepri nts , #167, Sept. 1979.
[72] Mendenhall, G. D. , and Nathan, R. A., "Evidence from a chemiluminescence

technique for bimolecular initiation in the autoxidation of tetralin,"

unpublished communication.

[73] Mendenhall, G. D. , and Klosterman, N. A., "Chemiluminescence from alkyl

hyponitrite decomposition," paper presented at the 8th International

Photochemistry Conference, August, 1975.

[74] Vichuti nski i , A. A., "Novel chemiluminescence methods for determination of

absolute rate constants for elementary radical reactions in the liquid

phase," Nature , 206 , 292 (1965).

[75] Vi chuti nski i , A. A., "Application of chemiluminescence to the study of some oxidation initiators," Zh. F. Khim. , 38, 1666 (1964); Russ. J. Phys. Chem.

,

38, 908 (1964).

[76] Karpukhin, 0. N. , Shlyapi ntokh , V. Ya. , and Mikhailov, I. D. , "Chemiluminescence and rates of elementary reactions in the simultaneous oxidation of cumene and ethylbenzene," Russ . J. Phys . Chem . , 38, 81 (1964).

[77] Karpukhin, 0. N. , Shlyapi ntokh , V. Ya. , Rusina, I. F. , and Zolotova, N. V.,

"A chemiluminescent method for determining the inhibitors of free radical

reactions," Zh. Anal. Khim., 18, 1021 (1963); J. Anal. Chem. USSR, 18, 882

(1963).
Table 1

Significant Reviews on Chemiluminescence

Author(s)/Year/Ref

.

Gundermann/1974/[1]

Heller & Ri chter/1974/[2]

Hercul es/1970/[3]

McCapra/1973/[4]

/197 2/ [ 5

]

/1970/ [ 6

Mendenhal l/1977/[7]

Popisova, Shlyapi ntokh

,

& Vassi 1

' ev/1965/[8]

Reich & St i val a/1969/ [ 9

3

Seitz & Neary/1977/[10]

Shlyapi ntokh et al./1968/

[ 11 ]

Title

Recent Advances in Research

on the Chemiluminescence of

Organic Compounds

Chemiluminescence in the

Condensed Phase: Measurements of Rates and Yields

of Excited State Formation

Physical Basis of Chemiluminescence

Chemiluminescence of Organic

Compounds

Chemi 1 umi nescence

The Chemiluminescence of

Organic Compounds

Analytical Applications

of Chemiluminescence

Chemiluminescence and the

Kinetics of Chemical

Reactions

Weak Chemiluminescence

During Hydrocarbon Autoxi dati on

Chemiluminescence and Bioluminescence Analysis

Chemiluminescence Techniques

in Chemical Reactions

Subjects

Molecular mechanism

of CL; Mechanism of

CL in HC autoxidation

;

CL from peroxide

decomposi ti on

Spectroscopy ; Radiometry

Instrumentation and

Calibration; Measurement

of absolute quantum yields

Molecular mechanism of CL

Molecular mechanism of CL

Molecular mechanism of CL

CL from singlet oxygen

CL from peroxide decomposi ti on Instrumentation; CL in

hydrocarbon oxidation;

CL analysis of complex

materials; Correlation

with stability; service

1 i f e

CL in hydrocarbon oxidation: kinetics; inhibitors;

catalysts

CL in hydrocarbon oxidation:

kinetics; inhibitors;

catalysts

CL in evaluation of material

degradation; Instrumentation

Instrumentation; CL in hydrocarbon oxidation: kinetic

methods; inhibitors; catalyst
Shlypi ntokh/1966/[12] Free Radicals and Chemi1 umi nescence

Vassi

1

1 ev/1970/[13]

/1967/[14]

71967/ l 15

]

Chemiluminescence Excitation

Mechani sms Chemiluminescence in Liquidphase Reactions

Chemiluminescence in

Sol uti ons

CL in hydrocarbon oxidation

inhibitors; kinetic methods

Molecular mechanism of CL

CL in hydrocarbon oxidation

Kinetic methods

Molecular mechanism of CL
Table 2

Summary of Chemiluminescence Kinetic Methods

Method Use Condi tions

Induction time Antioxidant evaluation Constant temperature

Onset temperature Oxidation stability Slow temperature scan

Activation energy

^Act

^ 0r i ni* tiation

or propagation

reacti ons

Arrhenius treatment

of t, or I , respectively

"S max

Oxygen drop

Dilution oxygen drop

Non-steady state

Overall oxidation

rate

Rate constant ratios

Shut off 0^ at a constant

temperature and monitor

'cl

vs 1

Vary conc'n (must know [0^]

or initial rate, w^)

Absolute rate constants Abrupt change in 0^ introduction or w.
Nathan

and

Mendenhall

Jet

Fuel

Stability o

Predicted

service

life/stability

of

jet

(40-42)

fuels o l o c cO •— E un o 1 CO

CO i- 4->

O CO a> Cl 3 O c S- *-> CO 4-> S- O o <4- rO c*— <0 c 3 4-3 t. • »— C GJ LO 03 ro 33 03 -o 4-3 c i- >0 O — 3 a; • r—

•r— o O

U •<-

X •— i—u >

CNJC co c*—C *->

C \ 4-> n: o o o C ro o> ro a: s- u uO o 0) 4-> •r- "O "3 -X i. 3 Cl

cn

u £- COu

— OJ «4— c co 0) •*— X •*-> o s. ro 4-3 o

•*— Ol 33 4-3 4^ c— c re • — o C CO

CO

u Ol co <4-

— 4-3 4-> o> Q_ 3 •— w a> 3) O) T3 CO •r— Vf- 4-3 3 > ro 4-3 C — i. -3 O O

03 S- S- •f— o> _)C 1 L

4-3 o> 4-> 33 c > fO— 4-> JZ. c o 3) (0 CO co O) a> •*— •— C c o

S- 3 4-3

O +-> >. H3 •1— •f— 3 ro r— O ro s- 03 03 4-> 4-) W c (O E t- u r— E c — CO c ro ro w o 3 0) a? CO Ol •r— — re C o 3 O

•I— 4-> *3 «— i- 4-3

O 4-> cO

C co mJ U a> 33 >— u 4-> c r— 03 —* >>

to rO • r- aj c i— E ro O) •»— 4-J •«- 4-3 3 o u CL .3 o — 0) Ol 3 u o to C) *r- S- r— ro 3 4-3 re — 4-3 •r- 3 /— X 03 CL L- 4-> S U ro X o c os — o 33 U— "3 u S- J- o u •*— 3 = CO c co O ro O 3 0) "C 4-> O' ro -X 3 3 3 c 33 x: c 3 03 3 CO 4-> u

03 •*- a» 33 3 —> re o> > O)

GC) CO o

s- 33 c i- o> CO £ •*— &. • r- S- c <D S- 4-3 3 O 03 3 C. >_ 3 x—v 3 4-> 3 03 C. -U "O CO

CO «C JZ o 3 03 c= <u c_> CJ co ro co 3 O 0) Oi a>

ro F— ro

—> O

— 0 0 ro r— ro •i—

— G. 4J CO

03 o> i- ro ai 33 01 s-

— 0) 03 O)

X 0) ro 03 E E < ^ > o u— 3 O o ff U E o => s. i- -3

0)X *.> CT> r>* oj ci i i a o 1 Ln —t w l i a '+- i o O o

to

CO

01 CO 3 3 Oi

Ol

O 3 > •r- 01 • f— 4-3 4-3

4-» ro

—

U 3 ro o» •f— j3 w X CL

Vfc— o CO UJ <

CO c—

4-3 o O c

fO 3 3 3 0

•»— 03 *— X r— 4-3 c o ro •r— s_ 3 4-3 • r— 3 01 X < CO- o

3) CO

L. >— 01 03 _3 -X 3 S01 c CO 3- 1 o» *— c -X c u w

C3 c 3 2 3 3 1 3 ro o

fO ro

u > "3

u as

O 3

•rm 3 ro > i ro '—

o r-*. E ro > i— ro — ro jZ 3 * 01 1 LX E sr r— GO s_ -Z Osj 3 <NJ ro Ul w' OO w

rated

additive

effectiveness

by

decrease

in

CL

intensity

compared

to

unformulated

oil

measured

oxidative

degradation

of

oils

by

decrease

in

CL

intensity

of

samples

from

conventional

bench

or

engine

tests
Related

CL

Studies

on

Simple

Hydrocarbons

m

toC

Ot£EC

CJ

C 0t rH c O CO 3 E c 3 •— 3 0 0 • •»— 1 CD “3 CO O -*J •p- 3 3 • 1— •+J •r- c 3 a •r— rc 3 -*J V- O 3. fD a- — rc -J —t 3 3 O • p— 3- .J 3- _3 ro •p— •r— <13 3 cn -3

a> •p- at

u - r— to •f— T— ro

CJ c 10 3 O E E X 3 E X E at 3 J> CL O to 0 —1 • r— 3 at 3 3 C to E u *r- CJ O w ^ 0 • a» 0 O at 3 3 E c c a C Ca CJ 3 <0 0-3 O

rO 0 CO

M 3 at at 3 D (C CJ 3 1— 3 O <TJ cr -3 • <J 3 JC at cr cr u 0 —t CM 0J <0 3> 3 0 0 i- CJ O E u 2 5 -j at 0 or O CO f— 0 c c 0 3 3 15 3

p—

—j —1 a

a to qc £ O 13

O

u 0 — 0 > -C 3 5 >> J3 •r— "3 = 0 E 3 -X -3 on T3 a> 3. u at v*- 0 at O u- 3 ro +j O c *-> O 10 “3 C 3 O 3 •• 3 3 at 3 a a u- 4-> 5 CO -Q >> •r- j3 >, at > at O at >>

cj cj •—

u -c 3 0 to c >S-J

—

X 3 c •*— 3 c 3> at e •f— <— 0 “3 O

-J at 3- j>

a to 0 *3 3 3 3

•r- 3. -j •»- 3 _3 _3 «_j 3 <0 u- -3 at < U a; C U -r- O - <0 LU O CO c.

-X 3

CL 3 +J

Ot 3 CO -> <b r—

<D 3 3 E 3 cj

ITJ (/) i

S-rc Ot (J Q- d ^

ro -J tO C C

a> o x o

LU CJ - ro << to m. »

CM to J3 >

CO

O - CJ CO CO 5 > 3 > > r—*1 - • 0 -X U CMfH - »—

1—1

-r— •f— c—t

/•-"V 0-4 0 d UfcJ < •3 * -J -3 1 1 3 u

p UJ CL •r* at • CJ

p *—1

(0 • •3 £ -3 3 SC -3 -3 ro 3 • t—t

LU (fln 3 •r- -3 UJ H- -x 3:

CO to to

p -X cr CO CO co to > > 3 3 > ^ > - > to > O C p at > -3 >

>—1 CJ >- r— <—« 'w' w' >—* —* w -X u—,

“3 3 1 3 ! . m, ^ a O 1 u 3 O -3 a> CJ *-> to 3 O 3 3 at (0 1 at

cr 3 CM »— c 0 ro 3 t- E 3 O CL 0 0 s- u ro — d CL 3 • *— O C s. (O • «— to CL S- E to 3 3

at »— c= 0 O 3 • r- at -u

O -ru » CO «uO

J3 ^ a *3 ro •p— to 4_> 3 sc s u . *> L. ro at ^ ro 0 u •r— J C-J u 3 to —>

*3

w ro 3 3 4J CU ro 3 .3 OJ r— cnj at 3 *J 0 ro ro O to r— ro 0 at —1 c J3 u> 0 cn w Q. 0 fO

co at J3 £ £ .3 "3

O ro s- E 'O CM Ut <0 M— E O r— CM an 3 3 at s- CO u 0 •r— O -r- ro 0 3 f— L. 3 Cl 0 3 O at u> •»— •p— 3 as CO m u> 5 do at r— QJ S— O

•i— 1 E 0 0-

O E -U rc 3 ro •r— 1 4-> CM ro 3>O 1 4J at 35O M—

O (O . - L. 3 O ro at to 0 u • E 3 to

U un at

u s- 3

co JO to jZZ • r— on 4-> 31 CO 3 at to 0 ro 0 u E — 3 3 CNI -X ro (O E "3 1 +L 1 un to 3 to •*— u 3 3 r—1 O 3 3 O •r— W u N1 r— c= 3 O "3 E »— O d O rc at O 3" S— U- 3 -3 ro O p—

JI “3 at 3J ro lT) E «o 3) _3 3 3 O <— -U TO 3 *-n s- . .

i- ro

O

u at

x

O a>

u CNJ “3 i- 3 at 1 C- «J at "3 r— »i— r^

u at at a> 1 <0

u an

at 4-t 3 m r— 4J 3 a *3 E <0 at at a> 3 E »— L. 3 Ju

u MC £ .*-> .

1 -C u E ro -3 r— O E 4J 1— to ,1 •p- -3 at 3 E 0 u 1 ro 0- O -3 at O 3 O £ ro ro to ro O on ro W 3 at 0

on 4-j

a 3 C- S- ty^ a> 3 r*H <U JO at at

u CSJ JO JO 3 U> rc iO

O 3. O

on CO i- -a to x- on <0

U ro >—

<0 un CO to > 4J CNJ JO

d -3 co 5 0 cr E to

m

at

>> c X •r- a to 31 O O at E CJ -

at 3 at 3

4-J

U

w •f—

to •»— ro to >, at 3 3 0

on 3 ' ' C Lm 0 3 JZ »— 3 CJ S- w

ro at CL. <0 > U E 3 U J • 1— CJ •— at c 3 a 3

at >n 31 X c

CJ an •—1 O LU

at a» 1 3 3 at 0

at •»— 3 1 £- * 1 fM > X r— 3

at 3 p 3 3 0 at

X > r— 3 at at a> L- 3 "at j3 -3 O c * 3 j3 -3 a> at 3 p pU at 3 E 3 a» 0 cl at 3. (M 1— a; a> 3 p O 3

<o 3 3 *— 3 3 ro 3 r— at at •f— hp- -a ro (O >> r— O n— a* —>

at >> rN 3 CL 3 X X -3 >> 3 >> .3 at cj SZ 3 at p O

jD at a>

J isj ro

O CJ at ro at E at 3 1 sc sz a> 3 4J M p <0 3 U at sz 3 3 3

CM 0 0 a 3 3 at 0 JC E O

u 0 UJ p— r— p sc a> at 3 • 3 -J w u d 3 u CJ at CL d •r- at •r— 3 O p CD •p- p

at >> >> 3 p 0 X 3 3 ro x: r- a; —4 3 < 3 u CJ ro a» * 0 3 p— LU -3 3 < 3" CO

ro CJ 3 u atJ

X

O >>Su at

O cc

J

pp at 0 3 at 0 L- 3 rsl

p 3 1 a> at 3 3 u CJ at s_ a> 3 -J p p 3 CJ 3 0

at 3 3 0 ro Cl. (*M at 3 >s a> QJ /—N at (O cu >> ^ a

sc ro (O 3 +l> a,

~~~ 3 at 0 •*— E 3 at -3 3 31 .3

p j 1 CJ 0 3. 3 CJ at 3 0 X 1— at 3 r— 0 CJ cn ro 3 CJ at r— at 0 O -3 at 3 0 3 M O >> sc CD r— 0 3 U -C •—1 E 3 L_ -C 3 *j -3 3 sc at 1 0 > 1 a» > at 3 at at -J <0 3 c .3 an 3 3 u CM -X «—•

on

u -3 c. on JC -x at

u *—»

>—•

UJ

u c 3 •rat 10to

•r— s •r- cn u 0 E H X 3

at 0

CNJ cl

•r— M— M— £ a- w 0 at 3 (O O ro at 3 0 •»— £ 3 >>

•r— 3 E 3 u 4_J (O 10 0 p c cn

rO sc •r—

U r— at ai

CJ <J 3 at .p- 0

•r- at ro at j U

r“

r—

d -3 -J 3 •p— r—

CL CJ ro at *4— at CL 1 at -j CD u- x: < 0 d CO w LU ^

ro

O

C > to O at 3- 3 DC O 3 — a;

at 1 3 r— 3

31 u. cn at ro •p- W O an 3C CJ to

p

p 3 O to to an 3 C 3 ro 3 lO rH O O to 3 3 > at i •t— •p— >> - -X CM 3

«J at SC 3 cXt • r* E •r— 3 3 3 O p to to CJ 3 O *3

•p—

O

p

O •f— 1 at 3 CL *3 u. -J O p

ro c:

X 0 >> ro

U co at 31 C O 3 3 r—4

•—

CJ

u <— at 3 • r- T3

p >

at at -J to -J

X 3 at

d 3 W 3 to

O ro r3 3
IX CM —3 c 05 to "OO OJ

fz 4— • p— 5 •— 1—4 U to X ,J2 to C -J x w

E x 3 •r— X OJ O O •-

i/l <D cn o 4-> c 1—4 03 2

• • L- 4-> -U> u • — X X JC o Z 3 4-3 -j c to u a> 4-J JC —3 • - 4-3 > C X J

OJ 4~> >, rc d L- c u o s- L. — L-i C- to o O 03 03 -3 o a* X 4-3 c

to Oi to CL cn E 4-3 3 G U 3 -

ai u a; J i_ O >» to x “3 C 3 O

JC u E o o S- X 3 X u. — "O'— / u x o 3 CL o O 03 3 4—3 O 4—3 C CD "3 tO •f— to r— 0> —— X S- X r

<D ^ o J- tO U- 4-3 —3 03 > o 4J 4-3 —

3 C5 •- 0- 0) X O to X u u i- s- tO C 4-3 c CL OIC. 2 03 • — X u a> 4-3 3 *P— 4

03 c u 03 S- 4-3 X to d O C

cm 3 •<- 3 d —1 S- 3 — 4-3 jC o d 4-3 — 4 O OJ -C c <D OJ 3 4-3 3 to 3 o u = CL < U X d 44 to X •*— > c 3 C —< u. to L. r- X c 03

IT! C O t/l "C 0) 03 "3 X o t_ O JE .d 3 4J — tO 03 S- CL 03 4-3 S. •f— 3 X 03 < 4-> d O" 3 —— u. c CL E c X o 4-3 4-> to 05 1 O 0) o •p— 03 •<— U r-3 X X U >> 3 I © 03 3 L. 4-3 E a> w E •r— 4— s- •*“ JC X < O) 4-J u o d L- jC u — JC 1— 03 4-> -3 1 5 — 3 3L 4-3 O 03 4-3 JC 03 X •— •r- CL 03 C U 1 O “3 "3 E X u 4-3 05 -U 4-3 _d u E 3 0 ’ — "3 0) O d u 03 O •»- 03 03 C to 03 — •— L- JO C L U = X o 4-3 JC Q s: — o 4—3 ^4-3 0 *'

tO tO > >

- OO©

-x ce

C" — d to 1 © 03 o = nc VO o 3 u •<— X d d o m C T3

CL X r^ - O CL i ^c CL X 4-3 0) X

~~ O 03 O 1 s- o o /*

S

o O U 3 > L- o 4-3 •— to

i. d 1 E JC t- £ o • — S— i— X •r— O 4J r>v 03 0 —

>

. - 3

"3 •»- o 4-3 "U i- 0 4-3 *o o 03 u £ 03 u /—

s

X* o> X i- U 03 1 4-3 X 1 • *» to

CM tO V i 3 CM -3 o E c CM CM —

J

- ao on 4-3 0 E 3 S- O “O ai O 4-3 s- d O O X E i— to o on X S- O 03

03 o “3 -W- — r-H o — X* 2: 4-3 O •4- 4-3 > 05 JC 03 JC 05 X 1 o— o 05 n* o nn x • - to to 4-3 1

o C 4-3 4-3 03 JC c uO d o d W 4-3 4-> LJ c * O to 1 X

«d — 03 4-3 4-> 3 •*- 3 CM •r— r^ •»— •f— 3 0) 0 c d E X 0 •r- W

X "3 E X 4-3 JC “3 •— i • f— 03 {= •4- X F—

•

CM 4-3 3 4.3 a» d 3 —

o d n “ o O 05 — —

tO — LT) to > cm o — to X lO i— to "O 3 r— X CL 3 X

X u tn o d o — U “3 03 J- m u T3 0) 4-3 X 1 £ O 4-3 >— — S- c 2: E u 4-> 3 O 4-3 4-3 3 O f— •— o S- L LJ 03 O —

>

0; •i— L 31 3 •—» jC ^3 U c •«— JC 4-3 u an o To X 0 to 4-3 U

£ 03 p*“v 4-3 (— 4-3 X 03 5 4-3 J2 to 03 M— to C 0) X on 3 .d © •— o on a> 4J a. on 03 3 0) CL 4J d CM 3 O 03 -3 CL uO on x 4-3 0 ^ to on e to on 0- on £ JC 4-3 to X .f- O to > CL to

1 p— u 0) 4» 0)

1 to I >, rH X d d

X d 3 - S- X 1 03 O

03 1 - x| 03 05 -C - u O 03 4J d Oi d

31 w 0 03 L- 31 4-3 — 1 03 S- 3 03 • 4- d •— O 0 - L 1 3 4-> 1 CL 3 •p- CM 3 >> < 03 s- 03 d — 03 0 f— 03 •p— < X O O 4-3 CD rM •> 03 3 04 3

u to - d F— > u c CD - 3 3 O 3 03 03 03 d O > 03 to X JC JC x 03 03 1 Q - a» 03 JC l a> 3 •r— JC 4-3 03 L. u > 03 u u 4-3 i- 3 3 O 1 p— 4-3 C O JC -r- X Cl x JC JC — 03 •p— a> JC X •<— f—

4

O 03 JC — 03 to »—

4

— X 0 O 3 -J

* —3 O 3 3 £ 43 3 X t-H d •1— S- —) •p— - >> 0 u ^ 03 r— d

03 X INI O • — d 3 O 05 • 03 3 4-3 — to O' 03 1 _d > X

d > X 3 - 3 X — L. -wp 05 U 03 •r-* L. • p— 4-3 03 CL 4-J 3 0 CD X 03 1 p— O' X d 4-> n*. - 03 CL O to JC 4J CD •

fst —

>

L. 0 - 3 - CL< - S- * c •— O < O L_ • 1— < 03 — < 3 C <L to d O' - C 03 C4 JC d CL 3 03 M C- - L. 3 -O X CD C CD

03 3 03 03 •i— M rH 03 3 O 03 4-3 • — 3 X Q 03 33 >s d - CC

«d - d d «— c -3 <h ^ 1 d d p— O) '

1 3 >, L_ — O - 1

1“ LJ O 0;

• — X 03 - CL U O O 03 X X — X vj O 03 JC 0> 3 O d LJ O

> LU C— '-3 — L JC ai •— 03 d M —4 U 0 L. > -3 03 3 03 pH rvi 03 22 *—

j

03 cu —4

JC m • X c 4-3 0 d 3 3 •*— 3 - X E 4-3 -NJ — 3! CD p— - 3 03 d CD C- —3 - £ 3 - —3 0 05 S— ro 03 s- a> 1 r— 03 05 L O 03 3 > • 1— —

•— O' 03 3 03 — O — O' d OJ O'

03 - 0 JC X 4-> 0 Nl O 4- X JC jd i_ 03 -> L. < i- JC 03 NJ < u x Up- 3 03 4-3 i- 3 f—l ^ u 4-3 JC JC 3 4-3 4-> E 3

3 < d >0 «d 0/ * 1 03 • • <. d •f— • P- 03 1 p^* c 03 . • 0 c <:

on X LlJ X CL on u -D G"5 rH "O 44 UJ X 3 on 3 CL r-i 3 UJ on u -3 LJ U UJ on UJ

E

to 3

•1— 0 - to 1 1 w El d *

4— <4- X X 1 C to tO X 4-J 4— 03 4-3 E •— 03 VI <4— • — u .d OJ X u X u £ 4-3 35 O to to d 1 L3 X

~ u O 3 to J. X

d 0- M— X 4—3 O O! 03 d - **- 3 *4— 03 s- — 03 C 3 03 JC 0; u E 03 to — X OJ JC to 4-3 d u CJ d to 33 u X r— u 03 03 U 3 CL X 03 •p— 3 s— 3 c d 03 4-J X 'X 3 4-J d 03 * o~ -X d 03 d 0 03 P-V 03 u — 4 d

03 03 u > to X L. X •— 21 u rn E • — ^ to S- p— 3 -3 U 03 L. p*—

d d —3 0 r^- 3 U J. O 0 to 3 **—

'

X - 03 f*s. 0 0 c » to X - 5 1 4— X >> 03 U— to 4-3 — oO •*— •p— 0 to u 3 d 1 -H 0 L- QC -4- jC d 4 3 3 >•— L •* 4-J 4-3 03 u P N • p— •«— X 0 rs^ >wP u P—

N

3 X X

0; 3 35 to O oD X X 3 03 O 4-3 X JC u •> >s3 0 CO O 4-3 3- X U to OD 3 3 d 0) O —3 CM 3 03 3 an 31 to >v 03 X 1 - • — •p— d L. 1 d X 3 *sr d SJ O 1 4-J d d

X —

1

3 > O m X X -J O CO • «— u- 2: d - 4J > — 0 on 03 0 O OJ Op W U CSJ O O 00 O •—

X on r— 4-> u an 21 3 u

Method

for

study

of

S:

ethylbenzene,

cycloSame

as

ref.

6

Ivs

t

Determined

decoinpos

i

ti

on/recom

-

initiated

oxidation

at

hexane

(Vassil'ev)

I

vs

[S]

bination

rate

constant

ratio

short

chain

lengths

I:

OCIIf'C,

A

I

UN

(Kj/Vk,.)

(Vicluitinski

i

,
Kinetics

of

simultanS:

cumene,

ethylbenzene I

vs

[S]

Cl

intensity

depends

strongly

eous

oxidation

of

1:

AIBN

(rate

constant

on

relative

concentrations

of

two

hydrocarbons

ratios)

the

two

hydrocarbons

(Karpukhin

and

Shlyapi

ntokh,

ref.

76) o s- 4J ai

•f“ 4-7 JZ OJc

JC 75 z u

•r- roCL

rz cn

co

rD -XC

C£ 73 -X i73 co

CJ Z

co

O 3 u

CZ

Cl.

•r- 73 2 —

"O

u o

ro cO

Ol r—

S- 7)

LOtD CM U O — CO 73

75 -C

S- 4-> — 5

>>XO

O >>

S- c u

O

V- > >,z

iu O 73

CJ JZ i-

«*-> o

4-> -3 —

07 JZ CL'— O -C — c

o> •— >

o>

k*— CZ O

CJ

S-o

07

C

-C o u —

CO 4-7 ro U 73

4-7

X

Ol

O

— 73 -X O)M

73 >>

0) *—

CL 73 O 4-7 — ro

O)U >

O' c o •-

CLEcc ^ U O)

4-> - rD

i- i—I -X LO

CO - CO z CO \ CO CO

U > > - 0 > co r- > > 73 z 3 4-7 .4- > -X LU 0

1—1

N- >—4

W

J t—1h-4 1—4 'w' •f—

4-7

<-> 01

•r— 73 4-7 0) 7)

CO s- i- jz 1 1 *u -C o>

4-* S- z 01 c 4-7 •*— iC • — 01 r— 0 —’ O • *— u 0 O

JZ /—SOl

u JZ *0

— £ 0 I 01 01

w

X • »—

w CJ co -D 01 4-7 —1 0 ^ 4—7 CL OI roJ

cO 0 CO CM 3 4-7

U COC cn -j 75 CO 4—7 E £ ro 73 73 0> 3 -Z 4-7 75 T3 • r— W E S- c •r- 1—4 73 O 0 > 75 01 O <4_ 73 4-7 •—

-ZO CO JZ CM 4-7 L. J3 73 "O

O jz c 0 4-7

X

4—> 4-7 1 z 4-7 0 CO 4-7 O) Ol rH

J 0 CO z JP

O o z 0 O O co Ol 1— J w- cn — 01 z 0 E •1— CD • r— i if? £ i« E JZ 4-> Z J c O •f— O r—

s— 4-7 ro S- 73 JZ ro <— 01 73 •<—

u 4-7 4-7 r—

lO 73

u CO . Ol

— z 4J <— r— •<—

J

U ro LO O 73 75 73 C £ O! C/0 JZ co ai 01 4-7 01 01 z 01 W

ZZ. r— 01 01

C 4-7 2ZO CJ > — >4- 4-7 73 c 01 JZ J J- JZ 03 ' S- e ro Z •f— 73 z •F— >

33 -Z 4-7 4-) Z 73 CJ r— 73 • <

^ — r—

U •rJ

O z 3 73 co 01 — 0 0> z 75 Ol CJ

03 -Q 4-4 CO

C c 0 CO 73 JZ 0 1! II II II II II II co ro lO cm O —

lO

O E C

3*>

— 4-7

O co LO <D Z CD 01

C/0 +J •—w >

>0 4J LO S- CD

lO 73 fO C't ^ 4-7 -X JP

O

01M 03 1 r— 01 c 73 O . - z 01 •rS- z 01 1— CO JZ X >> 0 Ol z 0 01 01 r— 0 u

r— JZ 01 4-7 z C >. s_ 01 c

_z CL E 75 r— 01

J 01

u •

- 4-7 E 4-7 CL 75 •f— 73 u 01 z 75 01 O Ol 4-1 u - z 01 L. 01 J CO • f—

01 01 - - 73 CL 73 - T3 4-7 73 M—

73 —7 01 01 4-7 r—

C O' >s 73 4-1 >5 U-

— 73 c CO z CJ > 73 z «j CO 73 01 X L_ 01 — 01 O J3 01 01 73 0 ro < IN» >, rsi 4— 4-7 CO < M 01 u >, O' E

S- ai CO z X z >> 01 r— CQ c z 73 73 4-7 z

01 4-7 Ol

C 01OO 01 01 73 CO

J

CL CO 1 J

u 0 —4 • — z 1 7s rsj 4-1 O’ z c C 0 r— J r— O L. 01 O r— z 1— 4-7 0 73

L. 01 z: z rH >, 01 •*— >> E 4-7 2£ DC 1—1

>> 01 73 cn Z 53 33 z CD 2: - jZ z z Zl. — 1 CO CL - zz JZ CT

Ol —4 cn —7 H3 4-7 "Z 1—4J 4—

O II II JZ. M < 0 -Z 01 1 - < 0) >> U II z _z —7 J3 CM jZ JZ cn

01 z i 01 z - - z < 4-7 LO LO

LO LZ

— *—•

UJ LO E •—«LO CNJ CM

—— UJ LO 01 <J cn 2:

>-

(V 73 • — CO

C

—

JZ

C

U lO

— 73 C L 73 — 73 01 JZ r- S- C 4-7 73 '3D O —7 i- - — ^ 01 01 CO

4-7 SDL 75 >o O) 73 73 C i— -X — 3 O O J- X 4-> — 03 O O uo w w ^

ro 73 E C

01 CO 0 JZ

cn 4—S c •r— •r—O •r— ro CD c co c 4-1 4-1 JC U 73 «=T •4- CO 4-7 73 ro CO CL c • z 4-> c— CO ZI “C3 ct- 01 •p— >> ro — 01 >, u •r— Ol U X 01 Cb- -Z L_ 01 X s— i- u z O jZ 73 01 •4- 73 73 E 0 O c J 0 z 4-> z z JZ z - J 73 - 4-7 CO • f—

•r» •4- z 73 zz /4-V ro 73 7^ z zz 01 ro

X >> 4-7 E 73 -X - • *— -X CJ z Ol 73 -X r— •4- O' r— 73 75 z z CO C 0 73 M 0 J s- 75 73

73 75 L. z • 1

4-1 - z >> > J co = -4- O’ 4-7 •r—

<4. >> 01 c JZ z cO 0 CO

O z Ol 75 z z 75

X

O <— -X

— -X • 1— ^3“ •4“

U re S- •—

J LO 4— LU CJ 0 ro J CL S- 4-7 z CL - 4-7 •4- 4—7 73 CL O U u O 0 7! CL 73 cD 73 4-7 73 JZ 73 O z II II II II II 73 •r- 01 4— 73 J >> ro 73 01 U -X >C uo 4-7 z 73 L— jC 1 p— 73 1 • 4- z 73 1 O JZ J 75 <4- LX 0 X LX ZI <7“ X • — L— rvj JZ GO c < c

co S— 01

U 0 '—

LO ro

O lx

O

w LO <3* u- LO >—1 UJ CJ •—11
Figure Captions

Figure 1. Typical intensity-time plot for CL oxygen drop experiment

Figure 2. Basic chemiluminescence apparatus
INTENSITY

TIME
RECORDER

NSS-114A (REV. 2-8C) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 82-2490

2. Performing Organ. Report No 3. Publication Date

April 1982

4. TITLE AND SUBTITLE

An Introduction to Chemiluminescence Methods for Lubricant Oxidation Studies

5. AUTHOR(S)

D.B. Clark, S. J. Weeks and S. M. Hsu

6. PERFORMING ORGANIZATION (If joint or other than NBS, see in struction s)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

10. SUPPLEMENTARY NOTES

_ Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual Summary o f mo st significant information. If document includes a significant

bibliography or literature survey, mention it here)

An introductory review of chemiluminescence (CL) techniques describes applications

for the study of oxidation of fuels and lubricants. Reviews of chemiluminescence and

oxidation are briefly discussed. The mechanism of CL as it applies to complex hydrocarbon systems is discussed. Several steady state and nonsteady state kinetic

methods are discussed with respect to the ability of each technique to give useful

information about the kinetics and mechanisms of oxidation. Applications of CL

techniques for fuels and lubricants, as well as simple hydrocarbon systems, are discussed.

The unique properties of CL methods for materials testing (e.g. lubricant oxidation stability)as well as fundamental understanding of chemical oxidation reactions are emphasized. Studies which evaluate petroleum and synthoil products, oxidation inhibitors and metal catalysts are discussed. Instrumentation capabilities are reviewed and

critical features of instrumental design are discussed.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons

j

additives; antioxidants; basestocks; chemiluminescence; fuels; hydrocarbons ; review;

kinetic methods; lubricating oils; materials testing; oxidation; petroleum products;

13. AVAILABILITY 14. NO. OF —

Unlimited

PRINTED PAGES

For Official Distribution. Do Not Release to NTIS ~ Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

37

15. P ri ce

X Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $7.50


It

f I