03/20 | Volume 146 | Thannhausen, Germany, March 12, 2020

home care

Why Proteins Improve Cleaning
Determination of CMCs

03
2020

englishskin &
hair care
Swiss Glacier Bacterium to Vitalize Tired Skin

antiperspirants

Shot of Well-being for Healthy Skin
Towards a Sustainable Solution for Skin Health and Well-being
Clay-like Ingredient for a Better Skin and Well-being

Effective Cleaning
through a Second Skin –Why Proteins Improve
Cleaning

Anti-inflammatory and Antioxidant
Cosmetic Ingredient for Holistic Skin and Hair Care

New Technologies forSpecific Antiperspirant Actions

Micellar Formulations – Old Wine in New Skins?

M. Reihmann, B. Köhler, N. Rittereiser, C. Yüce

SOFW Journal 03/20 | Volume 146 | Thannhausen, Germany, March 12, 2020

home care | cleansers

Effective Cleaning through a Second Skin – Why Proteins Improve Cleaning
M. Reihmann, B. Köhler, N. Rittereiser, C. Yüce

abstractAn innovative, easy-to-clean concept with hydrophilic protective layers formed by functional collagen peptides on cleaned surfaces, has been successfully employed in professional vehicle cleaning applications. This has allowed for the reformulation ofcleaners to less alkaline and more environmentally friendly conditions. In addition to improved cleaning results, extended cleaning
cycles and reduced water consumption are well documented benefits. Meanwhile these protein protection layers are also finding
use in hard-surface cleaners.

Here, the current focus is on effective ready-to-use cleaningproducts with simplified and reduced cleaning processes evenat mild alkaline pH levels. For the first time, the mode of action of these proteins was measured in real-time by means ofquartz crystal microbalance experiments. The data suggeststhat during a cleaning process multiple layers of proteins andsurfactants are formed on the surface. These layers create
an easy-to-clean effect by repeated application of a cleaning
formulation. Even after extensive rinsing with pure water, acompact protein layer remains on the surface which acts aseffective barrier against resoiling. The easy-to-clean effect of
this protective layer was also confirmed macroscopically withseveral exemplary household cleaner formulations according to
the IKW test-method for all-purpose cleaners on a scrub abrasion and washability tester (TQC Sheen).

Cleaning through a second skin – The role of proteinsin a formulationof consumers for products with an increased biodegradability
and a reduced microplastic footprint.
In order to overcome these challenge, the use of the protein-based
additive NOVOTEC® CB800 for surface protection in train cleaning
has been described [1-2]. NOVOTEC® CB800 is a concentrated
aqueous solution of specific collagen peptides, with an averagemolecular weight of 3.000 Da and a proline frequency of 14%
as well as a hydroxyproline frequency of 13%. When a cleaning
formulation is equipped with NOVOTEC® CB800, the polypeptide
chains of this natural product will form a protective hydrophilic
layer via self-organization during cleaning.
The proposed working mechanism of NOVOTEC® CB800 in
combination with cleaners [3] is shown in Fig. 1, which represents the cleaning of a train [4]:First, surfactants are removing soils (step 1). Simultaneously,
the protein molecules form a protective layer on the cleaned
surface. The protein molecules start to attach themselves tothe surface via polar interactions of carboxylic and aminogroups within the amino acid chain. A broad range of polarand non-polar side chain-functions assists the protein molecules to form layers on a wide range of surfaces.

Many cleaning formulations contain additives for the protection of cleaned surfaces. Most of thesurface protectants are based on water-repellant products, like waxes, silicones, andother hydrophobic film forming molecules.
The basic design of such products is to leavea cleaned surface in a water-repellant state.
This allows water to roll off from the cleaned
surface, taking the dirt and soil with it (e.g.
waxing a car after washing to obtain abeading effect). However, while this mightwork well for water-soluble stains, it is very
difficult to remove any dispersed water-insoluble compounds once this material has
been dried on the water-repellant surface.
Furthermore, almost all current surface proFig. 1 Scheme of the protective hydrophilic protein layer formation during cleaning of atectants are based on petrochemical prodtrain surface.
ucts, which strongly conflicts with the desire
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Next, the proteins form a stable network via self-organization(step 2). Polar proteins with a high proline and hydroxyproline
content have been found very effective for this purpose. The
protein network also incorporates water from the cleaning
formulation. On subsequent drying of the surface, the equilibrium moisture content of the protein film typically reaches
between 8% and 12% [5].
Once the layer is established, new soil can no longer reachthe cleaned surface and either flows along the water boundby the protein film or is removed as the protein layer is dynamically replenished during following cleanings (step 3). As
a result, the surfaces are easier to clean.
Luxembourg National Railway Company (CFL) reported a reduction of their washing time by 30%, combined with a reduction of fresh water consumption by 90% after using protein-based cleaners at their facilities [6]. The cleaners were
produced by Reinwerk Solutions, located in Bischheim, Germany. A total cost reduction by 50% displayed that the usage of
those protein-based cleaners is also commercially attractive [7].

Afterwards the glass plate was treated with different permanent markers. Next, the glass plate was washed with 40 °C
warm water for 30 seconds. On the right side, which was
pre-cleaned with the cleaning formulation that included theprotein-based additive NOVOTEC® CB800, the markers could
be easier washed away (Fig. 2, step 2).

Tracking the protein layer formation in real-time
To evaluate the protein-surface interaction during cleaning
in more detail, real-time measurements of the experimentmentioned above have been conducted using a quartz crystal microbalance instrument (QCM-D, QSense Analyzer). Thisequipment can measure the thickness of the protein layer
and potential other layers on variable substrate surfaces via
change of frequency (thicker layers will reduce the frequency)
as well as their viscoelastic properties by detecting the dissipation factor (higher value corresponds to more softness).

Example of the protein-induced easy-toclean effect on a glass surface
The easy-to-clean effect caused by the protein protective layers, can be visualized by
the following simple experiment: A glass
plate was washed with the same glass cleaning base formulation with and without theprotein-based additive NOVOTEC® CB800.
The left side was prepared without protein,right side with protein (Fig. 2, step 1). The
composition of the utilized cleaning formulation (including the protein-based additive)
is provided in Tab. 1.

Fig. 2 Glass cleaner with NOVOTEC® CB800 induced easy-to-clean effect
Step 1: Glass plate treated with different permanent markers before rinsing with purewater; Step 2: Glass plate after rinsing with 40 °C warm water.

Glass Window Cleaner (HCI/1001)
Hard Surface Cleaner with a good cleaning an wetting ability. Excellent skin mildness
Phase Ingredient
A

INCI

% w/w

Deionized water

Water

Qs

Carephos N (ICL)

Sodium Polyphosphate

0.20

Complexing Agent

GlucoPure WET (Clariant)

N-C8/10-acyl-N-methyl-glucamin

1.00

Surfactant

NOVOTEC CB800 (Gelita AG)

Gelatin Hydrolyzate

2.00

Additive

Phenoxetol™ (Clariant)Phenoxyethanol

0.50

Preservative

Sodium Hydroxide 10%

Sodium Hydroxide

Qs

pH – Adjuster

®

®

®

B

Function

Specification:
Appearance: clear liquidpH-value: 9.20 – 9.80
Viscosity: N/A
Stability test: Stable for 3 months at 4°C, 20°C and 40°C, 1 month at 45°C
Procedure:
I. Mix the components of phase A at room temperature until you have a clear solution.
II. Set pH-value with phase B.

Tab. 1 Glass cleaner with NOVOTEC® CB800 induced easy-to-clean effect.

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the protein-induced easy-to-clean effect:
The QCM-D was equipped with either gold sensors or gold
sensors sputtered with soda-lime glass. After equilibrating the• S oft multilayers consisting of protein and surfactants
sensors with air (step 1, Fig. 3) and water (step 2, Fig. 3), theare assembled during first cleaning
glass cleaning formulation equipped with protein as described• P artial dissolving of the layers due to release ofabove (Tab. 1) was pumped over the sensor, which resulted insurfactants facilitates cleaning
an immediate formation of a relatively soft layer with a calcu•A thin protein layer remains on the surface aslated thickness of 20-30 nm (step 3, Fig. 3). It is hypothesized
protection layerthat this layer consists of the protein layer on the sensor surface
and an associated layer of absorbed surfactants. Next, the sensor
was taken out of the QCM-D instrument and spin-coated with
Interaction of the proteins with surfactantsan ethanol-diluted permanent marker ink (step 4, Fig. 3). The
ink-soiled sensor was placed back in the QCM-D and the same
In order to better understand the interactions of surfactants
glass cleaner formulation was pumped over the sensor, but thiswith the protein, various combinations of surfactants withtime without including the protein in the glasscleaner formulation.
The high layer thickness caused by the ink
on the soiled sensor vanished within seconds (step 5, Fig. 3) and the layer thickness
dropped down to almost 5 nm followed byrestoring the initial layer thickness of 20 nm.
It can be assumed that the ink was washedaway together with the associated surfactants from the protein surface at the beginning of step 5 followed by a new surfactant
layer formation on the protein surface.
When water was pumped over the sensor,
the layer thickness dropped sharply down
again to 5 nm level (step 6, Fig. 3), as thesurfactants were washed away. The dimension of the remaining protein film on thesurface did not change on further rinsing
with water and stayed on the 5 nm level.
Fig. 3 Ink removal from NOVOTEC® CB800 covered gold surface visualized by QCM-D
In summary, the QCM-D real-time measurereal-time measurements. Similar results were achieved on a glass-sputtered gold sensor.
ments suggest the following mechanism for

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NOVOTEC® CB800 have been analyzed regarding their surface
tension and contact angle towards cleaned substrates. A previous study [8, 9] included the following surfactants [10, 11]:
DODECYLDIMETHYLAMINE OXIDE, SODIUM 2-ETHYLHEXYLIMINO DIPROPIONATE, SODIUM N-LAUROYLSARCOSINATE,
SODIUM ETHYLHEXYL SULFATE, SODIUM CAPRYLOYL GLUTAMATE, TIPA-LAURETH SULFATE, N-C8/10-ACYL-N-METHYLGLUCAMIN, N-C12/14-ACYL-N-METHYL-GLUCAMIN-NCOCO-ACYL-N-METHYL-GLUCAMIN, C10-12 FATTY ALCOHOL EO/PO-ADDUCT, COCO-BETAINE,COCAMIDOPROPYL BETAINE, ALKYL HYDROXYETHYL DIMETHYL AMMONIUM CHLORIDE, SODIUM LAURETH SULFATE, SODIUM LAURETH SULFATE.
Among all of these surfactants, synergistic interactions – i.e. alower surface tension with increasing amount of NOVOTEC®
CB800 protein – have been observed with glucamin-based
surfactants and SODIUM CAPRYLOYL GLUTAMATE; antagonistic results have been found for SODIUM 2-ETHYLHEXYL IMINO DIPROPIONATE. The surface tension of the othersurfactants did not change significantly in combination with
NOVOTEC® CB800. Concentrations of up to 2.5% protein in
a 5% surfactant solution were examined.
The synergistic acting glucamine-based surfactants have beenchosen for further analysis of the surfactant-protein interaction during cleaning.

Protein and surfactant concentration and its influence on
the cleaning performance
The effect of the surfactant and protein concentration on thecleaning performance was studied by varying the final working dilution of two all-purpose cleaning formulations. One
formulation contained NOVOTEC® CB800 and for the otherformulation the additive was replaced by water to maintainthe amount of the other ingredients (Tab. 2). Surface tension
and contact angle were determined by optical contact angle measuring and contour analysis system (Dataphysics OCA50), the reported values are the average of 3 measurements.
The cleaning performance was evaluated by using a scrub
abrasion and washability tester (TQC Sheen).
For the performance evaluation, the current version of the
IKW test-method for all-purpose cleaners [12] was adapted.
As studying the protective effect requires protein pretreatment prior to soiling, it was necessary to extend the established IKW test-method by inclusion of an initial cleaning stepwith the selected formulations. It was decided to simply copy
the conditions of the cleaning step for the pre-cleaning.
Following the IKW test-method for all-purpose cleaners, thetest soil consisted of 75% peanut oil (Mazola), 23% kaolin
and 2% carbon black. The defined test substrate (floor tiles
by Villeroy & Boch 3135 30x30cm) was cleaned with ethanol and the test cleaner formulation (5ml) was applied tothe surface with the defined towels (Wecovi 02010100, cut
to 13x10 cm) by wiping 20 strokes within one minute on a
scrub abrasion and washability tester (TQC Sheen). In thenext step the test soil was applied on an area of 8x26 cm
by screen printing. The soil was burned at 100 °C for 24 hfollowed by a setting step for 24 h at room temperature. In
the final step the tile was again cleaned with the defined
towels wetted with 5ml of the test cleaning formulation.
This cleaning cycle consisted again of 20 strokes within one
minute.
The application of the concentrated cleaner did not showa major difference in the cleaning performance. That was
mainly because the cleaner formulation was powerfulenough to remove the test soil even without protein pretreatment effectively with 20 strokes (Fig. 4). This experiment verified, that the cleaning formulation was adequately
formulated to remove the test soil.

Kitchen Cleaner (HCI/1006)
Kitchen Cleaner against grease with an easy to clean effect. Excellent skin mildness.
Phase Ingredient
INCI
A
Deionized water
Water
Carephos® N (ICL)
Sodium Polyphosphate®
GlucoPure DEG (Clariant)
N-C12/14-acyl-N-methyl-glucamin
NOVOTEC® CB800 (Gelita AG)
Gelatin Hydrolyzate
Genaminox® CSL (Clariant)
Coco dimethyl amoneoxide
Isopropanol
Isopropanol
Phenoxetol™ (Clariant)Phenoxyethanol
B
Sodium Hydroxide 10%
Sodium Hydroxide

% w/w
Qs
0.30
2.00
2.00
1.50
1.00
0.50
Qs

Function
Complexing Agent
Surfactant
Additive
Surfactant
Solubilizer
Preservative
pH – Adjuster

Specification:
Appearance: clear liquidpH-value: 9.50 – 10.00
Viscosity: N/A
Stability test: Stable for 3 months at 4°C, 20°C and 40°C, 1 month at 45°C
Procedure:
I. Mix the components of phase A at room temperature until you have a clear solution.
II. Set pH-value with phase B.

Tab. 2 All-Purpose cleaning formulation with NOVOTEC® CB800 induced easy-to-clean effect.

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While the surface tension of both cleaning formulations
was almost similar (28.3 and 28.9 mN/m respectively), clear differences were visible regarding the contact
angle of the cleaning formulations on a tile washedwith ethanol, but without further pretreatment. The
protein-based cleaner showed a contact angle of 6.6°
while the formulation without NOVOTEC® CB800 had
a contact angle of 11.7° (Fig. 4). As the surface tensionof both cleaners was comparable, the lower contact angle of the protein-based cleaning formulation must becaused by an immediate formation of hydrophilic protein layers once the formulation came in contact withthe tile surface.
The impact of the protein protection layers on thecleaning process was clearly visible once the cleaning
formulations were diluted with water. The previously mentioned cleaning experiment was repeated, but
this time with an aqueous 1:1 dilution of the cleaning formulations (with and without protein) describedin Tab. 2 for the protein based cleaner. Each diluted
cleaner was used for the corresponding pre-cleaning
and the consecutive cleaning step. The test soil was
still effectively removed with 20 strokes from the
NOVOTEC® CB800 protection coating, although the
pre-cleaning step generating the protein layer was performed with the diluted cleaner. The side of the tile,which was pretreated with the cleaning formulation
without NOVOTEC® CB800 remained soiled after 20
strokes (Fig. 5).
The analysis of the surface tension and contact angle
gave very similar results as received with the non-diluted cleaners. While the surface tension of both cleaners
was again almost equal (27.9 and 27.7 mN/m respectively), the contact angle measurement resulted in 4.5°
for the protein containing cleaner versus 10° for theprotein-free cleaner on a tile washed with ethanol, but
without further pretreatment. Thus, obviously eventhe diluted cleaner was effectively releasing enoughprotein on the surface of the tile during the first cleaning step, to build a hydrophilic protection layer andmake the second cleaning more effective.
In summary, these results are indicating an interesting
method for cutting cost of cleaning formulations, especially in applications where cleaners are applied regularly and/or repeatedly.
Differences between cleaning with and without protein protection were also evident at high dilutions (1:5). When the tile was pre-cleaned with the highly diluted cleaning formulations with and without NOVOTEC® CB800, there was still a major difference visible
after 20 strokes of the second cleaning step. However,the final cleaning result was not sufficient for both formulations (see Fig. 6). This indicates that neither the
low protein concentration in the pre-cleaning step nor
the surfactant content in the actual cleaning step were
sufficient to remove the dirt completely. Interestingly,
56

Fig. 4 A tile pre-washed with concentrated cleaner with/without NOVOTEC®
CB800 and cleaned again with the respective cleaners shows only a minor
improvement due to protein protection of the first cleaning.

Fig. 5 A tile pre-washed with 1:1 diluted cleaner with/without NOVOTEC®
CB800 and cleaned again with the respective cleaners shows a major
improvement due to protein protection of the first cleaning.

Fig. 6 A tile pre-washed with 1:5 diluted cleaner with/without NOVOTEC®
CB800 and cleaned again with the respective cleaners shows only an
improvement due to protein protection of the first cleaning but the final
cleaning result is not satisfying.

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cleansers | home carehowever, the determined contact angle values for the 1:5
diluted cleaners on the untreated tile were quite similar tothe values determined for the 1:1 dilutions, which suggeststhat the hydrophilic protein protective layers are formed
even with highly diluted detergent formulations. Thus, theunsatisfactory cleaning result is probably primarily due to an
insufficient surfactant concentration.

Conclusion
The presented results show that the performance of water-based cleaners may be boosted by adding small fractionsof the protein-based additive NOVOTEC® CB800 to the formulation. During cleaning, the proteins attach themselves tothe surface and form stable hydrophilic layers by self-organization. These layers attract water and provide an easy-toclean effect. Any soil formation on cleaned surfaces can beremoved more easily and effectively. QCM-D analyses suggest that if NOVOTEC® CB800 is combined with surfactants,
soft multilayers consisting of protein and surfactants are assembled during first cleaning. These layers partially dissolve
during subsequent cleaning, releasing surfactants that facilitate the cleaning while a thin protein layer remains.
This opens new opportunities to create more natural cleaners
and at the same time provide very cost-effective cleaning formulations by lowering the surfactant concentration.
Moreover, the presented protein-based additive, NOVOTEC®
CB800, as a natural polymer, is fully biodegradable, has a very
low allergenic potential, protects skin and is not subject of
discussions on microplastics in contrast to synthetic polymers.

Acknowledgements
The authors would like to thank Christopher Schmid, Quantum Design GmbH for the QCM-D results, Stefan Wiemer,
Ter Ingredients GmbH & Co. KG for providing the cleaning
formulations, Dr. Paul Pawelzyk, GELITA AG for surface tension measurements and Dr. Eric Yezdimer, GELITA USA for
scientific contribution, Selina Seip, GELITA AG, for the workwith the scrub abrasion and washability tester and Marina Arnold, GELITA AG for the work with the optical contact angle
measuring and contour analysis system.
References[1] Becker, H., 2016. Nachhaltiger Lackschutz dank Proteinen. Eisenbahntechnische Rundschau, 3, 48-51[2]	Becker, H., 2016. Sauber bis in die Bilanz. Sauber, 1,22-24[3] Cleaners produced and distributed by Reinwerk Solutions, Bischheim, Germany[4]	Pictures released by CFL (Luxembourg National Railway Company)[5] R. Schrieber and H. Gareis., 2007. Gelatine Handbook: Theory and Industrial
Practice, Weinheim, Wiley-VCH, 107[6] Tesch, D., 2018. Der perfekte Wasserkreislauf. Sauber, 3, 18-21[7] Becker, H. 2017. Proteine schonen Umwelt und Budget. Eisenbahntechnische
Rundschau, 3, 20-21[8] R eihmann, M. , et al., 2018. Effective Cleaning with a Second Skin. SEPAWA
Congress, Berlin, October 12[9] R eihmann, M. , et al., 2019. Why Proteins Improve Cleaning. SEPAWA Congress, Berlin October 29[10] Kindly provided by Zschimmer & Schwarz GmbH & Co KG Chemische Fabriken[11]	Kindly provided by Ter Ingredients GmbH & Co. KG[12]	IKW Recommendation for the Quality Assessment of the Product Performanceof All-Purpose Cleaners 2014, German Cosmetic, Toiletry, Perfumery and Detergent Association (IKW), Frankfurt, 2014

contact
Dr. Matthias Reihmann | Head of Global Product Management Photo/Technical
Dr. Berthold Köhler | Manager Administration/Research & Business Development
Nina Rittereiser | Product Manager Photo/Technical Europe
Dr.-Ing. Ceren Yüce | Technical Specialist/Technical Product Management Photo/Technical
GELITA AG
Uferstraße 769412 Eberbach | Germany
Corresponding author:
matthias.reihmann@gelita.com

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