bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Protein Adsorption and Conformational Change on DLC and Ti Surfaces Using FTIR and Coomassie Brilliant Blue Protein Assay
Authors: Yan Huang , Lü Xiao Ying , Huang Nan
Published: March 2009

The aim of present work was to study the interaction between human plasma protein-albumin (Alb) and immunoglobulin G (IgG) and the surfaces of two kinds of diamond-like carbon (DLC-A and DLC-B) and titanium (Ti) film. Fourier transform infrared spectroscopy (FTIR) was used to perform both quantity investigation and secondary structure analysis of above two proteins adsorbed on material surfaces. A modified Coomassie brilliant blue (CBB) protein assay was also used to study the amount of adsorbed proteins. The result of FTIR quantitative evaluation shows that the ratio of adsorbed Alb to IgG (RA/I) on three kinds of material surface has an order: DLC-A > DLC-B > Ti, which is coincide with the result from CBB protein assay. The result of secondary structure analysis shows that the conformation of Alb and IgG changes in a largest degree after adsorbed on Ti and a smallest degree on DLC-A surface. Both the results indicate that the anti-thrombogenicity of DLC-A seems to be the best and Ti is the worst.
Investigation on the Biomimetic Scaffold for Bone Tissue Engineering Based on Bioglass-Collagen-Hyaluronic Acid-Phosphatidylserine
Authors: Chen Xiao Feng , Wang Ying Jun , Zhao Na Ru , Yang Chun Rong
Published: March 2009

The new type of bone tissue engineering scaffold composed of the sol-gel derived
bioactive glass particles, type I collagen, hyaluronic acid and phosphatidylserine were prepared
through cross-linking and freeze-drying techniques. SEM observation indicated that the scaffold
possessed a 3-D interconnected porous structure and a high porosity. The properties of
bio-mineralization and cells biocompatibility were investigated using SBF immersion and cells
culture methods combined with SEM, XRD and FTIR techniques. The study revealed that this
biomimetic scaffold possessed satisfactory functions of cells attachment, bio-mineralization, and
cells biocompatibility. The porous structure and the surface of the scaffold which was covered by a
bone-like HA crystal layer due to bio-mineralization were profitable for cells attachment and
spread.
Synthesis of CaO-P2O5-SiO2 Monolithic with Double Pore Structure by Peg /Starch
Authors: Yang Hong Bin , Chen Qi , Song Li , Li Hui Ping , Lu Jian Ying , Zhang Wu Zhi
Published: March 2009

Porous CaO-P2O5-SiO2 monolithics with double-pore structure were prepared from
tetraethoxysilane, triethylephosphate and calcium nitrate by a sol-gel method. Polyethylene glycol
and starch were used as mesopore-making agent and as macropore-making agent, respectively. The
porous monolithics, having mesopores with ~20 nm pore size and macropores with 7~20 μm pore
size, could be formed from the removal of organic components after heated at 600°C for 2 hours.
After soaked in simulated body fluid (SBF) at 37°C for 7 days, bonelike apatite was formed on the
surface of the samples. The porous samples were degraded gradually in SBF solution.
Comparison of Porous Ti6Al4V Made by Sponge Replication and Directly 3D Fiber Deposition and Cancellous Bone
Authors: Li J.P. , Wijn J.R. , van Blitterswijk Clemens A. , de Groot K.
Published: March 2009

The present investigation gives a comparison of the structure and properties of porous Ti6Al4V made by sponge replication (Sponge Ti) and directly 3D fiber deposition (D3DF Ti) and cancellous bone. Although the macrostructure of these two materials differs, their microstructure seems to be similar. Both scaffolds reveal an open pore structure, while D3DF Ti shows a fairly regular open pore structure, sponge Ti6Al4V exhibit an irregular open pore structure similar to that of cancellous bone. The mechanisms resulting in mechanical properties like stiffness or strength are, accordingly, different. The compressive strength and E’ modulus of Ti6Al4V scaffold are higher than that of cancellous bone,. The permeability results show both Ti6Al4V scaffolds are quite comparable with cancellous bone.
Instrumented Indentation of Layered Ceramic Materials
Authors: Jiménez-Piqué Emilio , Gaillard Yves , Anglada Marc
Published: March 2009

This paper gives a short review of the instrumented indentation technique when applied
to ceramic layered materials. The main causes of error are commented, together with the effect of
the substrate, the microstructure and the possible fracture events.
Porous Multilayer PZT Materials Made by Aqueous Tape Casting
Authors: Palmqvist Lisa , Lindqvist Karin , Shaw Chris
Published: March 2009

Porous piezoelectric ceramics are of interest for hydrophones and medical imaging
because of their enhanced coupling with water or biological tissue due to acoustic impedance
matching. Multilayer lead zirconate titanate (PZT) substrates with dense and porous interlayers
were produced by tape casting of aqueous PZT slips with high solids contents. The use of latex
binders with low viscosity enabled addition of starch as a fugitive additive to create air/ceramic
composites with ´3-3´connectivity. Microstructures, piezoelectric and mechanical properties of
sintered, poled laminates were evaluated. The relative permittivity, ε33, decreased by 40% for
laminates with porous interlayers compared to dense ones, whereas the relative decrease in
piezoelectric longitudinal coefficient, d33, was 35%. Laminates with porous interlayers maintained
72% of their bending strength compared to dense ones.
Roughness Effect on the Mechanical Properties of Ceramic Materials Measured from Nanoindentation Tests
Authors: Rico Alvaro , Garrido Miguel Angel , Otero Enrique , Rodríguez J.
Published: March 2009

An experimental study was performed to evaluate the roughness effect on the
determination of hardness and Young´s modulus of ceramic materials from nanoindentation tests.
Several specimens polished at various stages were tested at different peak load values. Local
roughness measurements have been done by means of atomic force microscopy. Results indicate
that roughness and size effects are joined. Proportional Specimen Resistant Modified model
(PSRM) was applied to avoid the scale effect, isolating the roughness influence. Indentations where
the average roughness-elastic displacement ratio is lower than a critical value are needed to get
consistent results.
Development of Bio-Mimetic Patterned IPMC Actuators with Multiple Electrodes
Authors: Jeon Jin Han , Oh Il Kwon , Han Jae Hung , Lee Sun Woo
Published: March 2009

The ionic-polymer-metal-composite actuators can easily actualize the bio-mimetic
fish-like locomotion owing to their best merit for large deformation. And novel fabrication methods
of IPMC patterned with multiple electrodes were developed to apply the different driving waves to
the multiple electrodes. Generally, the IPMC actuator has been fabricated in electroless plating
technique, while it is high time-consuming process, showing poor repeatability in the actuation
performance due to the variables in the process of fabrication. Therefore the several fabricating
methods was newly investigated by combining electroless plating, photolithography, physical
sputtering and electroplating techniques capable of precisely patterning and actuating of the multiple
electrodes. On the whole, four different methods were compared and analyzed in similar thickness
level of Platinum electrodes. Consequently, the mixing the electroless chemical reduction and
electroplating can be a promising candidate for the low time-consuming method and the better
bending performance.
Active Vibration Control of the Print Circuit Boards Using Piezoelectric Bimorphs
Authors: Yeo H.C. , Guo N. , Du H. , Chen M.
Published: March 2009

Piezoelectric bimorphs were assessed for their capabilities to be used as control actuators
for vibration suppression of the print circuit boards (PCBs). Plate structures made of FR-4, a widely
used industrial-grade material for manufacture of PCBs, were considered. An advanced and
structured control algorithm, linear quadratic regulator with output feedback (LQROF), was used for
active vibration control of the PCB structures. Experimental results showed that the LQROF control
is a more robust algorithm than the classic control using the direct velocity feedback, and
piezoelectric bimorph actuators present a great potential for active vibration control of the PCBs, and
smart composites with embedded actuators.
Formation of Apatite within Biodegradable Scaffolds by an Accelerated Biomimetic Process in the Shaking Condition and Flow Condition
Authors: Chen Yun , Mak Arthur F.T. , Wang Min
Published: March 2009

Bonelike apatite coating was formed on poly(L-lactic acid) (PLLA) scaffolds and poly(glycolic acid)
(PGA) scaffolds in 24 hours through an accelerated biomimetic process. The ion concentrations in the
simulated body fluid (SBF) were nearly 5 times of those in human blood plasma. The apatite formed
in 5SBF was similar in morphology and composition to that formed in the classical biomimetic
process employing SBF or 1.5SBF, and similar to that of natural bone. To facilitate coating into
scaffolds, the flowing condition was introduced into the accelerated biomimetic process. It was found
that the accelerated biomimetic process performed in the flowing condition yielded more uniform
spatial distribution of apatite particles than that in the regular shaking condition.
Microstructural Design of Ceramic–Metal Composites for Tribological Applications
Authors: Hussainova Irina
Published: March 2009

The properties, performance, and reliability of a cermet material depend mostly on the
intrinsic properties influenced by microstructure that evolves during processing and use. In this
study, the effect of microstructure on reliability of multiphase materials in erosive media is
analyzed with reference to WC-, TiC-, and Cr3C2 - based ceramic-metal composites. Microstructure
of multiphase materials, fracture mechanisms, ability of energy dissipation, thermo-mechanical
parameters and erosion resistance are examined. It has been shown that microstructural variables
play a very important role in cermets performance. The energetic criterion of non-homogeneous
materials selection has been presented.
High-Velocity Impact Characteristic of Mg Alloy and CFRP Composite
Authors: Hwang Do Yeon , Shimamoto Akira , Takayama Kazuyoshi
Published: March 2009

This study examined the dynamic penetration phenomena of high-velocity impact of
magnesium alloy CFRP (Carbon Fiber Reinforced Plastic) composite. Test materials for
investigation are magnesium alloy(AZ31B), the heat-treated magnesium alloy (AZ31B-200°C,
AZ31B-300°C, AZ31B-430°C), and carbon/epoxy laminated composite materials with fiber direction
[0°]8, [0°/45°]4s, [ 0°/90°]4s, [ 0°/45°/90°]3s and [ 0°/45°/-45°/90°]2s. We used a ballistic range
(one-stage light gas gun), and the test specimens were set at 0°obliquity at room temperature. A
high-speed camera allowed us to capture and analyzed the dynamic penetration phenomena of the test
specimen.
Electrical Conductibility of Copper Clad Steel Wire by Drawing at Room Temperature
Authors: Wu Yun Zhong , Ma Yong Qing , Gao Hong Tao , Zhang Yang , Liu Shi Yong
Published: March 2009

By application of clad-bonding technique of pure copper sheet and plain low carbon steel
rebar Q195, the cladding wires in different diameter by drawing at room temperature have been
worked. The increasing ratio of the area of grain boundary is in direct proportion to deformation
approximately. The resistivity of the cladding wires go up in direct proportion to deformation
because the increment of the area of grain boundary results in increment of static disfigurement to
electron dispersion. When deformation is less 9.6, the relative increment of resistivity is less 1.1%,
i.e. the wire is provided with good electrical conductivity. And the resistance and resistivity of the
wires can be estimeted based on copper ratio of transverse section of the cladding wire and the
deformation by drawing at room temperature.
Modeling of Smart Materials of Nanostructure in a Poorly Electrically Conducting Fluid Saturated Composite Materials
Authors: Rudraiah N. , Ng C.O.
Published: March 2009

To meet the demands of technology for the development of new materials with tailormade
properties, we propose the use of smart materials of nanostructure synthesized by solidifying
a poorly conducting alloy in a microgravity environment in the presence of an electric field and
surface tension. Energy method combined with a single term Galerkin expansion is used to find the
condition for the onset of Marangoni marginal electroconvection (MMEC) in a composite material
modeled as a porous layer. It is shown that a proper choice of electric parameter and the ratio of
Brinkman viscosity to viscosity of the fluid λ control Marangonielectroconvection (MEC).
Effect of Water Absorption on Compressive Strength after Impact and Post Impact Fatigue Behavior of Woven and Knitted CFRP Laminates
Authors: Saito Hiroshi , Kimpara Isao
Published: March 2009

The effect of water absorption on the compressive strength after impact (CAI strength) and
the post impact fatigue (PIF) properties of CFRP laminate were evaluated. Materials used were plain
woven T300B-3K CFRP laminates and multi-axial knitted T700S-12K CFRP laminates molded by
the vacuum assisted resin transfer molding (VARTM) method with vinylester as the matrix. Coupon
specimens, which were applied the impact energy (1 J per unit thickness), were soaked in a water bath
at 95oC for 120 hours up to the saturation water content of 0.6 wt%. CAI and PIF strengths of ‘Dry’
and ‘Wet’ specimens of plain woven CFRP showed almost same values. Thus, for T300B plain
woven CFRP laminates, the effect of water absorption on PIF properties was small. On the other
hand, multi-axial knitted CFRP laminates showed the large effect of water absorption, and Wet
specimens showed lower PIF properties than Dry ones. However, net CAI and PIF strengths of
multi-axial knitted CFRP were larger than that of plain woven CFRP.
Injection Molding of Fiber Reinforced Plastics by Using Extracted Glass Fiber from FRP Waste
Authors: Nishida Yuichi , Kimura Teruo , Shibata Katsuji
Published: March 2009

This report proposed the injection molding method of thermoplastic composite materials
reinforced by the glass fiber extracted from FRP waste. Glass fiber was pre-treated by card
machines and mixed with PP fiber. The sliver-type glass/PP mixture was fed into the injection
molding machine directly. As a result, the glass fiber reinforced PP composites were obtained.
The mechanical properties of the fiber reinforced composites were measured and discussed. It
is concluded that the extracted glass fiber is good for the reinforcement of composite. The
result suggests that the injection molding method described herein shows promise for
contributing toward the material recycling of glass fiber extracted by the normal pressure
dissolution method.
Microstructure and Properties of CuW50Cr25 Composite
Authors: Xiao Peng , Liang Shu Hua , Peng Qing Yan , Fan Zhi Kang
Published: March 2009

CuW50Cr25 composite prepared by infiltration was investigated. The results show that
the microstructure consists of four phases: W-rich and Cr-rich CuWCr solid solution as well as
Cr-rich and Cu-rich CrCu phases. The original Cr particles in the compact are replaced part by
Cu-rich CuCr phase and part by Cr-rich CrCu phase which is the first breakdown phase in the
course of the material’s arcing. The chopping current value of CuW50Cr25 composite is 2.4A and
arc duration is 4.01ms. These properties are much more excellent than counterpart of CuW70. The
breakdown strength is 2.31×108 V/m and comparable with the CrCu contact materials.
Scratch Behaviour of EPR-Rich TPOS
Authors: Browning Robert L. , Sue Hung Jue , Ohtani Kousuke , Ijichi Yasuhito , Iseki Yuki
Published: March 2009

The scratch behavior of a set of model soft thermoplastic olefin systems containing at
least 65 wt% of ethylene-propylene rubber (EPR) in polypropylene was analyzed using a
standardized progressive load scratch test. It was found that raising the ethylene content in the EPR
introduces crystalline phases, as evidenced by differential scanning calorimetry, and significantly
alters the scratch behavior. A strong effect was also observed by changing the rate at which the
scratch test was applied. This paper will discuss these effects based on the scratch damage
mechanisms observed.
Influence of Margin Geometry on Failure of Brittle Coatings on Compliant Substrates: Relevance to Failure of Dental Crowns
Authors: Qasim Tarek , Whitton Anne , Ford Chris , Bush Mark , Hu Xiao Zhi
Published: March 2009

This paper explores the so-called “margin failures” observed in loaded curved bi-layer
structures. Hemispherical bi-layer model test specimens consisting of glass shells with varying
margin geometry filled with epoxy resin, simulating brittle crowns on tooth dentine, are loaded with
compliant indenters along the (convex) axis of symmetry. Using this unique setup, the influence of
margin geometry on margin failure is examined. Nearly all previous studies have utilised hard
spherical indenters of various radii, and examined crack initiation and evolution at the contact point.
However, the modes of fracture observed in this traditional contact problem, surface cone cracking
or flexure-induced radial cracking initiate close to or inside the (small) contact area, and thus not
explain the margin failures commonly observed by dentists. Crack growth at the margins distant
from the contact zone cannot be generated under indentation using hard spherical indenters. The use
of a compliant (soft) indenter distributes the indentation force over a large contact area, generating a
compressive zone underneath the contact, and effectively inhibiting the modes of fracture typically
observed using hard indenters (radial and cone cracking). Consequently, significant tensile stresses
at the support margin become dominant, and the focus shifts to fracture initiating at the support
margins. In this study, cylindrical indenters composed of PTFE Teflon, with a modulus several
orders of magnitude lower than the indented materials, are used to examine margin fracture in
brittle crown like structures. The specific focus is the effect of margin geometry – Chamfered;
Round; Shoulder margins are examined, and their influences on crack initiation and damage
evolution are reported.
Influence of Tapered Brittle Coatings on Stresses in Layered Structures: Relevance to Failure of Dental Crowns
Authors: Ford Chris , Qasim Tarek , Bush Mark , Hu Xiao Zhi
Published: March 2009

This paper uses Finite Element Analysis to examine stresses in loaded curved bi-layer
structures. The model system consists of glass shells, both constant thickness and tapered, filled
with dental composite. These systems, simulating brittle crowns on tooth dentine, are loaded with
ultra-compliant disk indenters, and hard spherical indenters for comparison, along the (convex) axis
of symmetry. The resulting maximum principal stress patterns are analysed.
Previous studies have generally utilised hard spherical indenters of various radii indenting
constant thickness coatings, and examined stresses leading to crack initiation. However, the peak
stresses observed in this traditional contact problem – inducing surface cone cracking or flexureinduced
radial cracking - occurred close to or inside the (small) contact area, and do not explain the
margin failures in dental crowns commonly observed by dentists. Furthermore, the effect of
varying coating thickness, especially tapering towards thinner margins, has not previously been
examined. The use of an ultra-compliant indenter distributes the indentation force over a large
contact area, generating a compressive zone underneath the contact, and consequently, previously
insignificant stresses at the support margin become dominant, and the focus shifts to the support
margin, rather than the area close to the contact.
In this study, balsa wood is used as the disk indenter model material, with a modulus several
orders of magnitude lower than the indented materials. Stress patterns from the same systems
indented by hard spherical indenters are included for comparison. The specific focus is the effect of
tapered coatings, examining stress patterns from several geometries. Results confirm not only a
shift in the peak maximum principal stress from the near-contact area (under hard spherical
indenters) to the margin area (under ultra-compliant indenters), but also show that coating taper can
have a significant influence on the margin stress under a soft indenter. In the same systems indented
by a hard indenter, coating taper has very little effect on the more localised stresses induced.
Propagation Characteristics of Lamb Waves in Stringer-Stiffened Panels
Authors: Yang Chun Hui , Su Zhong Qing , Ye Lin , Lu Ye , Bannister Michael
Published: March 2009

Stringer-stiffened plate-like structure is a typical engineering structure and its structural
integrity is critical. A guided Lamb wave-based damage identification scheme and an online structural
health monitoring (SHM) system with an integrated PZT-sensor network were developed. In the
previous studies, the specimens were relatively simple. In this paper, the abovementioned method was
extended to the stiffened plate-like structure—a flat plate reinforced by stringer. FE dynamic
simulation was applied to investigate the Lamb wave propagation characteristics due to the existence
of stringer with the consideration of its material and geometric configurations.
Experimental Characterization of Poly (Ether Ether Ketone)/Multi-Wall Carbon Nanotube Composites
Authors: Deng Fei , Ogasawara Toshio , Takada Nobuo
Published: March 2009

In this study, poly (ether ether ketone) /carbon nanotubes (CNTs) nano composites were fabricated by using multi-walled carbon nanotubes (MWNTs) as the filler. Tensile properties of nano composites at before and after glass transmission temperature were studied. At room temperature, the addition of 15 wt% MWNTs increased the tensile modulus (0.10.3% strain) by 89% and the yield stress by 19%. At after glass transmission temperature (200) , they increased by 163% and 42%, respectively. The experimental results showed that the reinforcement of CNTs are more effective for high temperature than room temperature. DMA results showed an increase in storage modulus with increasing MWNTs loading fraction at both below and above the glass transition temperature Tg (around 145oC). Scanning electron microscope and transmission electron microscope images showed that the MWNTs were well dispersed in the matrix and orientated one direction.
Fire Performance of Nylon Nanocomposites Fabricated by Melt Intercalation
Authors: Varley Russel J. , Groth Andrew M. , Leong Kok Hoong
Published: March 2009

This paper presents results of a study carried out to evaluate the effects of an
organomodified nanoclay, either on its own or in combination with a polyimide, upon the fire
performance of a commercially available nylon. The fire performance, as determined using cone
calorimetry showed that up to 40% improvement in the peak heat release rate could be achieved at
addition levels of only around 5wt% of nanoclay. The level of improvement was shown to be
strongly dependent upon nanoscale dispersion with a more highly exfoliated morphology, as
determined using transmission electron microscopy, which showed a greater reduction in the peak
heat release rate compared to a more ordered intercalated structure. Investigation of the mechanism
of fire retardancy showed that the reduction in the heat release rate is due to the nanoclay
reinforcing the char layer which prevented combustible products from entering in to the gaseous
phase. Generally, though, the time to ignition is unaffected by nanoclay additions. The addition of
the polyimide to the nanoclay reinforced nylon was inconclusive showing little evidence of further
improvements in fire performance.
The Bending Strength of Medium Density Fibreboard (MDF) from Different Ratios of Kenaf and Oil Palm Empty Fruit Bunches (EFB) Admixture for Light Weight Construction
Authors: Jamaludin Mohd Ariff , Kamarulzaman Norlida , Ahmad Mansur
Published: March 2009

The use of alternative materials from agriculture and plantation bio-mass has widely been
researched especially for use in bio-composites. These bio-mass have been used in flour form as
fillers, in fibre form as reinforcements and in both flour and fibre forms as bulking agents. These
bio-mass not only enhanced the composites but also help to reduce the burden on natural fibres from
the forests. Furthermore, these bio-mass fibres can be used as an alternative or supplementary raw
material in composites such as fibre glass-polymer composites by replacing part of the synthetic
fibres, if not all, depending on the final application of the finished composites. Combining one
material with other materials provides a strategy for producing advanced composite materials that
take advantage of the properties especially bending strength of both types of resources. It allows the
researcher to design materials based on end-use requirements within a framework of cost,
availability, recyclability, energy use, and environmental considerations. This paper reports on the
bending strength of MDF from kenaf, oil palm EFB, and from admixtures of EFB and kenaf in
different ratios. Production of composite material from these diversified resources will not only
help to reduce the pressure on natural forests, it is also an alternative to overcome waste disposal
problems in palm oil industries. The results indicate that kenaf and EFB could be mixed to produce
MDF. The panel produced can be used for furniture components such as table tops and shelves,
wall partitions and door panels.
Electromagnetic Interference Shielding and Mechanical Properties of Maleic Anhydride Functionalized MWNT and Poly (urea urethane) Nanocomposites
Authors: Wu Han Lang , Ma Chen Chi M. , Wang Chung Hao
Published: March 2009

The functionalized multiwall carbon nanotubes (MWNTs) have been prepared by free
radical reaction with maleic acid and maleic anhydride. The functionalized MWNT was further
blended with poly(dimethylsiloxane) (PDMS) based Poly(urea-urethane) (PUU). Both maleic acid
modified MWNT (Maa-g-MWNT) and maleic anhydride modified MWNT (Mah-g-MWNT) showed
enhanced dispersion compared with that of pristine MWNT and PUU.For MWNT/PUU
nanocomposites containing 5 phr functionalized MWNT, the maximum microwave absorption was
-19.2 dB for Maa-g-MWNT/PUU nanocomposites and was -22 dB for Mah-g-MWNT/PUU
nanocomposites.
A Nonlinear Mechanical Model for Tension of Bundles of Single-Walled Carbon Nanotubes
Authors: Xiao Tan , Ren Yu , Wu Ping , Kin Liao
Published: March 2009

Tensile strength distributions of multi-walled carbon nanotubes (MWNTs), single-walled
carbon nanotube (SWNT) ropes and sub-bundles are studied by statistical approach based on the
experimental data sets. It shows that the distributions can be adequately described by a two-parameter
Weibull model. Considering further their nonlinear stress-strain behavior, the force-strain relation
and tensile strength of SWNT bundles are studied. The Weibull modulus of the sub-bundles in a
SWNT bundle can be estimated in terms of the maximum sustained force and the failure strain of the
bundle. A SWNT bundle was subjected to tensile testing using a nano-mechanical testing device. The
result suggests that the nonlinear behavior of SWNTs does affect the force-strain relation of SWNT
bundles, mainly at large strain.
Preparation and Characterization of Chitosan/Hdroxy-Aluminium Pillared Montmorillonite Nanocomposites
Authors: Tan Wei , Zhang Yi He , Szeto Yau Shan , Liao Li Bing
Published: March 2009

It was shown that chitosan and hydroxy-aluminum pillared montmorillonites were
excellent materials for the removal of dyes and metal ions from effluent of dying and finishing.
Chitosan/ hydroxy-aluminum pillared montmorillonite nanocomposites are expected to play a
multiplex role in the treating process. In this study, the nanocomposite was prepared by incorporating
hydroxy-aluminum pillared montmorillonite into chitosan solution that diluted acetic acid was used
as solvent for dissolving the chitosan. The ratio of chitosan to the cationic exchange capacity of the
montmorillonite was about 1:1, 2:1, 3:1, 4:1 and 6:1, respectively. The nanocomposites were
characterized by XRD (X-ray diffraction), SEM (Scanning Electron Microscopy). The experimental
results indicated that the presence of hydroxy-aluminum cation was in favor of the chitosan
intercalation and the interlayers of MMT was intercalated with the bilayers of chitosan sheets. and
they can be used in absorption of organic and metal ions for dying and finishing effluent.
Crystallization Behaviour of Nano-ZnO/PET and Nano-ZnO/Polyethylene Glycol (PEG)/PET Composites by In Situ Polymerization
Authors: Tao Jie , Dong Xiang , Wang Tao , Cui Yi Hua
Published: March 2009

In order to improve the crystallization properties of the polyethylene terephthalate (PET), nano-zinc
oxide (nano-ZnO)/PET and nano-ZnO/polyethylene glycol (PEG)/PET composites were
successfully synthesized by in-situ polymerization method in this work. The experimental results
indicated that nano particles can accelerate the crystallization of the PET which was demonstrated
by increase in the intensities of the XRD peaks. PEG and PET form copolymer in composites,
leading to the improvement of the flexibility of the molecule chain. Meanwhile, PEG was able to
encapsulate the nano particles to make them have both good compatibility to matrix and uniform
dispersion in the composites. Therefore, the crystallization rate and crystallization capability of
nano-ZnO/PEG/PET composites were reasonably raised.
Observation on Hydrophilidae Cuticle and Analysis of Maximum Pullout Force of Branched Fiber
Authors: Chen Bin , Peng Xiang He , Fan Jing Hong
Published: March 2009

Most structural materials existing in nature take the form of composite. After centuries’
evolution and modification, these natural materials gain highly optimized structures and prominent
performances. The SEM observation on the cuticle of Hydrophilidae shows that the cuticle is a
biocomposite reinforced with chitin fibers. The chitin fibers are embedded in a protein matrix of the
cuticle in the form of layers. A kind of revolving fiber layup was found. Observation also shows that
there is a kind of special branched fiber consisting of a long fiber and many short fibers. The
maximum pullout force of the branched fiber is analyzed. The results show that the maximum
pullout force of the branched fiber is distinctly larger than that of ordinary straight fiber.
The Influences of Solid Loading and Molding Variables on Alumina Injection Molding
Authors: Liu Xiao Jun , Yi Zhong Zhou , Huang Kang Ming , Xie Zhi Peng , Huang Yong
Published: March 2009

Two kinds of commercial alumina compacts made by injection molding with different solid
loading are studied. Solid loading is the key factor for the injection molding process and the properties of
green body and sintered compacts. The results show that higher solid loading leads to better properties of
the compacts such as density and fracture strength, however the viscosity of the feedstock would increase.
Smaller sized alumina powder leads to a higher critical solid loading value. Macroscopic defects such as
voids and cracks could be introduced into the injection molding samples if the molding variables are not
optimized. The properties of sample are improved by adjusting the variables such as injection pressure,
holding pressure, holding time and barrel temperature.
On the Defects in Injection-Moulded Technical Ceramics
Authors: Yu Xin Gang , Liu Lan Yun , Zuo Yan Bin , Xie Zhi Peng , Wu Bo Lin , Yang Jin Long , Li Jian Bao , Huang Yong , Wang Lin , Gong Yi
Published: March 2009

A heated sprue device for ceramic injection moulding was used to research the defects in injection-moulded technical ceramics. By use of the heated sprue device, the problem of sprue solidification was resolved and the density of the injection moulding specimens was increased while the defects eliminated. The influence of the processing parameters on the defects of the injection molding specimens was investigated in detail by X-ray radiography camera and photograph. It turns that the sprue solidification time has much influence on the defects in injection-moulded technical ceramics. Reasons causing the results above were also analyzed. Based on the research, bars of 20mm in diameter without macroscopic defects and turbine blade of fine property with Si3N4/SiC(w) materials were prepared by injection moulding.
The Effect of Diluent on Combustion Synthesis of Si3N4-SiC-TiN Ceramics with Small Diameter
Authors: Zhang Xue Jun , Zheng Yong Ting , Han Jie Cai
Published: March 2009

Si3N4-TiN-SiC multiphase ceramics was synthesized from TiSi2 and SiC powders by combustion synthesis. The effect of dilute content on conversion percentage was calculated in theory assuming that there is no penetration of nitrogen gas, and combustion synthesis was carried under different conditions. The results show that the increase of diluent content in certain extent is helpful for nitrification of TiSi2 and free silicon were detected in the 30wt% and 40wt% SiC-diluted samples with 45vol% porosity while no silicon were found in 50vol% porosity green parts. The increase in diluent content and porosity of the compacts are favorable for the development of rod-like β-Si3N4 and the long-diameter ratio of β-Si3N4 is increase as the increase of these two values.
Preparation of Porous Wollastonite Ceramics for Filtration
Authors: He Ming Sheng , Li Jian Bao , Li Bo Wen , Lin Hong , Yang Xiao Zhan , Liang Long , Guo Gang Feng
Published: March 2009

Wollastonite powder was selected as a starting material with carbonate as pore-forming agent
and binder added. The porous ceramics were prepared at different temperature by sintering method. The
process includes batching, granulating, pressing molding, drying and sintering. It is discussed the
influence of sintering temperature, dosage of binder, dosage of pore-forming agent, pressure of molding
and holding time on the performance of porous ceramics. According to the principle of particles stack, the
porous wollastonite ceramics for filtration with various diameters, shapes and porosity were fabricated by
serial experiments. These products have 1 to 10 microns in pore size, 30.04 to 66.15% in porosity, 2.82
m2/g in specific surface area.
Effects of Adding Form of Additives on the Structure and Properties of High-Purity Alumina Ceramics
Authors: Ren Qiang , Wu Xiu Lan , He Xuan Meng
Published: March 2009

High-purity alumina ceramics was prepared using high-purity α-Al2O3 powder as raw material,
nitrates or oxides of magnesium, chromium and copper as additives by a wet ball milling with a later dry
pressing forming and normal pressure sintering process. The influence of additives on the sintering
temperature, microstructure and bending strength of the prepared alumina ceramics was studies. The
results showed that the additive doped with nitrate can be dispersed uniformly in the body with molecule
scale, and the oxides obtained by decomposing of nitrates have the higher reactivity. Thus, the nitrate
additives have better capacity than oxide additives in reducing the sintering temperature and inhibiting
the abnormal grain growth, and the alumina ceramics prepared by adding of nitrate additives have higher
density and bending strength.
Preparation of Zirconia-Toughened Alumina Ceramics through the Dispersal Basic Carbonate Precursors
Authors: Wang Jie Qiang , Yu Qing Hua , Zheng Shao Hua , Wang Zhi
Published: March 2009

Using NH4HCO3 solution as precipitant, the ultrafine 3Y-ZrO2/Al2O3 precursors were prepared
by the liquid-phase precipitation method. The well-dispersible ZrO2/Al2O3 composite nanopowders with
particle size 10nm were obtained by calcining the precursor at 1000°C. The XRD patterns show no
γ-Al2O3 and θ-Al2O3 formed during calcination. The powders have excellent sinterability and the relative
density of specimen is up to 99% after sintering the green compacts at 1550°C. Microstructural analysis of
the sintered bodies reveals the uniform distribution of the zirconia grains in the alumina matrix.
A Study on Toughening and Strengthening of Mg-Al Spinel Transparent Ceramics
Authors: Huang Cun Bing , Lu Tie Cheng , Lin Li Bin , Lei Mu Yun , Huang Cun Xin
Published: March 2009

Transparent Mg-Al spinel ceramics of four different nonstoichiometries were obtained
utilizing two-stage sintering technique of vacuum sintering and post hot isostatic pressing using
MgO·nAl2O3 powders with n of 1, 1.3, 1.5 and 1.8, respectively, as raw materials. The mechanical
properties of the ceramics were measured and indentation shapes and radial crack propagations were
observed. The results showed that change of molar ratio of Al2O3 to MgO leads to variation of
indentation shapes and crack propagations of the ceramics, resulting in the change of mechanical
properties of the ceramics. The flexural strengths of the ceramics increase first then decrease with
increasing n. However, the hardness and fracture toughness of the ceramics increase with increasing n.
As a result, an optimal n for high performance ceramic is suggested to be 1.5. In addition, mechanisms
of toughening and strengthening of the transparent ceramics have also been discussed.
Structure and Dielectric Properties of Homogeneous Srm-3Bi4TimO3m+3 (m = 3, 4, 5, and 6) Ceramics
Authors: Fang Wang Sheng , Du Pi Yi , Weng Wen Jian , Han Gao Rong
Published: March 2009

Srm-3Bi4TimO3m+3 (m =3, 4, 5, and 6) bulk ceramics were prepared by conventional solid-state reaction process. Their phase structures and morphologies were observed by XRD and SEM respectively. The dielectric properties and hysteresis loops of the ceramics were measured by impedance analyzer and hysteresis meter respectively. Results showed that the lattice parameters along the c axis are 32.79, 41.11, 48.83, and 58.17Ǻ for m=3, 4, 5, and 6 respectively. The microstructures of plate-like crystalline phases are shown in all the ceramics with different m. Curie temperature of Srm-3Bi4TimO3m+3 decreases from 668°C to 295°C with increasing m from 3 to 6. The remnant polarizations Pr are 32.46 and 19.44 μC/cm2 for odd m of 3 and 5, and 11.84 and 10.58 μC/cm2 for even m of 4 and 6 respectively.
Preparation and Properties of β-Si3N4/Epoxy Matrix Composite
Authors: Tang Jin , Chen Ke Xin , Fu C.S.
Published: March 2009

Thermally conducting, but electrically insulating, polymer-matrix composites exhibiting low
dielectric constant are needed for electronic packaging. For developing such composites, this work used
silicon nitride particles as fillers and epoxy as matrix. The thermal conductivity of Si3N4 particles
epoxy-matrix composites was increased by up to 31.4 times than that of neat polymer by silane surface
treatment of the particles prior to composites fabrication. The increase in thermal conductivity is due to
decrease in the filler-matrix thermal contact resistance through the improvement of the interface between
matrix and particles. At 45.4 vol. % silane-treated Si3N4 particles only, the thermal conductivity of
epoxy-matrix composites reached 9.72W/ (m*K). The dielectric constant was also low (up to 5.0 at 1
MHz). However, Si3N4 addition caused the flexural strength and ductility to decrease from the values of
the neat polymer.
The Reaction between Ti3AlC2 and Cu in the Synthesis Process of Cu/Ti3AlC2 Composites
Authors: Peng Chun Qing , Wang Chang An , Song Yang , Huang Yong
Published: March 2009

In this work, the reaction between Ti3AlC2 and Cu in the synthesis process of Cu/Ti3AlC2
composites has been studied. According to the results of XRD, SEM and EDS, Ti3AlC2 reacts easily with
Cu to generate TiC and intermetallic compound Cu9Al4 when the holding temperature is higher than
950°C, no matter how much Cu is contained. In addition, when the content of Cu increases, more layered
Ti3AlC2 grains react with Cu and form irregular shaped grain containing Cu, Ti, Al and C elements.
Therefore, the Cu/Ti3AlC2 composites cannot be synthesized above 950°C by hot-pressed method if no
specific treatment is used.
Mechanical Properties and Microstructure of Al2O3-TiC Composite by Hot-Pressing
Authors: Shi Sui Lin , Zhang Ling Zhen
Published: March 2009

In this study, Al2O3-TiC composite was prepared at 1600°C for 1 h by hot-pressing using the Al2O3-TiC composite powder synthesized from self-propagating high-temperature synthesis (SHS) process. Mechanical properties of the composite were investigated, such as bulk density, Vickers hardness, fracture toughness and bending strength. The microstructure of the composite was also investigated by scanning electron microscopy (SEM).
Plating Copper on Al2O3 Powder in Ceramal
Authors: Li Chang Hong
Published: March 2009

Copper film was plated on Al2O3 ceramic powder in Al2O3 ceramic with copper matrix. The influence of copper film plated on Al2O3 ceramic powder to friction coefficient and amount of wear has been studied in this paper. Variance analysis shows that copper film on Al2O3 ceramic powder does not have significance influence to friction coefficient, but has significance influence to amount of wear of Al2O3 ceramic with copper matrix. Amount of wear of Al2O3 ceramic with copper matrix decreases with the increase of copper film plated on Al2O3 ceramic powder initially. When the copper film plated is beyond 47%, The amount of wear reaches a stable volume, and almost does not reduce again with the increase of the copper film plated on Al2O3 ceramic powder. To Al2O3 ceramic with copper matrix in this paper, the optimum copper film plated is 47%.
Densification of Unfired Alumina Refractories by the In Situ Spinel Formation during Application
Authors: Yang J.H. , Youn Sang Heum , Kim Jae Jun , Hwang Kyu Hong , Lee Sung Gap , Jun B.S. , Yoon Seog Young , Lee Jong Kook , Kim Hwan
Published: March 2009

To prevent the shrinkages by the densification during the application of unfired Al2O3-C
refractories or Al2O3 castables in steel making conditions, MgO was added as aggregate or matrix powder
and the expansion caused by spinel formation was studied. Because the spinel was formed at the
contacting areas between Al2O3 and MgO particles and the volume of in-situ formed spinel increased
more abnormally at the side of Al2O3 particles than MgO, the addition of MgO aggregates was not
recommendable due to the formation of large voids around the MgO aggregates. Nevertheless, corrosion
resistance was increased with the amount of fine MgO added, and the finer MgO powder added, the better
residual expansion and minute structure formation was observed. In the contrary, in case of castables
volume expansion due to spinel formation was not obvious because the degree of densification was less
than high-pressure formed refractories. But CA6 phase would not form around alumina aggregates during
corrosion so the corrosion resistance was much more enhanced.
Investigation on the Porous Biomaterial for Bone Reconstruction with Addition of Bio-Mimetic Nano-Sized Inorganic Particles
Authors: Zheng Hua De , Wang Ying Jun , Yang Chun Rong , Chen Xiao Feng , Zhao Na Ru
Published: March 2009

The spherical nano-sized bioactive particles in the system of CaO-P2O5-SiO2 were bio-mimetically synthesized using micro-emulsion method. The microstructures and properties of the bio- mimetic nano-materials were characterized using XRD, FTIR, SEM/EDAX and TEM techniques. It was indicated that the nano-particles possessed glassy structural characteristics. The porous composite for bone tissue reconstruction was prepared by compounding poly (hydroxybutyrate-2-co-2-hydroxyvalerate) (PHBV) and the nano-particles of bio-mimetic bioactive glasses (BMBG). Bone-like hydroxyl- carbonate-apatite (HCA) could formed on the surface of porous composite by immersing the composite in simulated body fluid (SBF) at 37°C for 8 hours. With increase of immersion time, the morphology of HCA changed from spherical into flake-like crystals. The study on cells attachment of the porous PHBV/BMBG composite proved that the material possessed satisfactory bioactivity, bio-mineralization function and cells biocompatibility.
Effect of CNTs on Property of Calcium Phosphate Cement
Authors: Zhao Ping , Sun Kang Ning , Zhao Tai Rong , Ren Xue Hua
Published: March 2009

The effect of carbon nanotubes (CNTs) on bending strength of calcium phosphate cement was investigated. The cement composite powders, containing 0, 0.2%, 0.4%, 0.6%, 0.8% and 1.0wt% CNTs respectively, were prepared by ball milling. It was found that the presence of CNTs improved the bending strength of the cement from 6.6 MPa to the best 10.5 MPa. The reason for mechanical property improvement is related to the fibers (bars)-like microstructure of the reinforcing element, with CNT in the core and hydroxyapatite crystals growing on it.
Effects of Setting Liquid on α-Calcium Phosphate-Tetracalcium Phosphate Bone Cement
Authors: Li Xu , Yang De An , Di Li Zhi
Published: March 2009

Calcium phosphate cement (CPC) is a kind of promising materials used in dental and
orthopeadic restoration. Nowadays, CPC is of special interest due to its self-setting behavior when mixed
with an aqueous liquid phase. In this study, α-tricalcium phosphate (α-TCP) and tetracalcium phosphate
(TeCP) were served as the solid component of the cement, and the liquid component was consisted of
sodium phosphate dibasic dedocahydrate (SPDD, Na2HPO4·12H2O), and/or citric acid. The cement’s
properties as compressive strength and porosity were measured. The effects of preparing conditions, such
as liquid-to-powder ratio (L/P) and liquid composition, on compressive strength of calcium phosphate
were investigated. The results show that the compressive strength increases with the decreasing of pH
value. There is a premium L/P in which the compressive strength gains its maxim. The compressive
strength reached 21.69 MPa at the condition of L/P = 0.30mL/g and pH =5.
Preparation and Characterization of Biodegradable β-TCP-Based Composite Microspheres as Bone Tissue Engineering Scaffolds
Authors: Zan Qing Feng , Wang Chen , Dong Li Min , Liu Rui , Tian Jie Mo
Published: March 2009

Since a small globular particle was first used as support for three-dimensional (3D) growth of anchorage-dependent cells in suspended cultures, a variety of microspheres as tissue engineering scaffolds have been developed. In this paper, β-TCP and chitosan were selected as the components of microspheres due to their biodegradability and osteogenic properties. The biodegradable β-TCP/chitosan composite microspheres were prepared by a solid-in-water-in-oil (s/w/o) emulsion cross-linking method in this paper. The size distribution, surface morphology, and microstructure of the microspheres were evaluated. Scanning electron microscopy revealed that the size of the microspheres with good spherical morphology was distributed in the range of 50~200μm. In vitro immersion experiments were carried out to evaluate the degradability of the microspheres, and the results demonstrated that the chitosan/β-TCP composite microspheres were potential materials as tissue engineering scaffolds for bone repair.