Abstract: Composite nanoparticles of Ni-TiC and Ni-TiN were prepared by an active plasma-metal
reaction method. The structure and morphology were evaluated by X-ray diffraction and transmission
electron microscopy observations. The morphology of the composite particles is dice-like or
dumbbell-like, where the outer sides are metallic and the inner part of the rod (or dice)-like structure
is TiC or TiN. The formation mechanism of the composite particles is considered by analogy to the
VSL mechanism. The thermal stability of the nanocomposite particles is vastly superior to that of the
metal particle. The excellent catalytic property of the Ni-TiN composite particle was confirmed when
compared to the well-known Raney Ni particle and mixed particles of Ni and TiC.
Abstract: WC nanosized powders are synthesized by the plasma arc discharge process and annealing
under an inert (Ar) atmosphere. The high temperature used during discharging at local region causes the
work-piece and electrode to melt and evaporate. The melted tungsten on the arc discharge electrode and
carbon arising from decomposition CH4 gas forms WC1-x nanosized powders. The WC1-x phase is
encapsulated in a amorphous carbon shell. The WC1-x nanosized particles are annealed at 1200~1400°C
under an Ar atmosphere. The WC1-x nanosized powder is transformed to the W2C phase, and then it
becomes WC above at 1400°C.
Abstract: A peptizing-hydrothermal method to prepare nanometer γ-AlOOH crystal powder with
industrial Al(OH)3 as raw materials has been proposed in the present paper. The XRD and TEM results
show the product is a pure γ type nanometer AlOOH crystal powder with average grain diameter of 70nm.
Laser grading analysis indicates the average grain diameters of the product in the solution are 66.52nm in
water and 84.33nm in N,N-dimethylformamide, respectively without surface modification and dispersant.
The experimental result indicated that polymer/inorganic nano-composite with high content of nanometer
AlOOH presents inorganic characteristic of polymer. The wear rate of the alumina ceramic ball sintered
at 1465°C from ceramic, which contains 98 % alumina (wt), can be reduced up to 40% with addition of
3.5% nanometer AlOOH.
Abstract: Nano-particle hydroxyapatite (HAp) was directly prepared by a wet chemical precipitation
method with the aid of ultrasonic irradiation in solution using Ca(NO3)2, NH4H2PO4 and NH2CONH2 as
source materials. The nano-HAp formation rate at different preparation temperatures and under different
ultrasonic irradiation powers was measured and the influence of ultrasonic irradiation power on the
synthesis kinetics of the nano-hydroxyapatite was investigated. It was found that the nano-HAp content
increased with the increase of ultrasonic irradiation power, preparation temperature and reaction time.
Under different ultrasonic irradiation power, an Arrhenius relationship was found between the nano-HAp
formation rate and preparation temperature. It showed that with the increase of ultrasonic irradiation
power from 100W to 200W and 300W, the synthesis activation energy of nano-HAp crystallites decrease
from 63.2 KJ/mol to 59.9 KJ/mol and 48.1 kJ/mol respectively by calculation.
Abstract: Hydroxyapatite nanoparticles were synthesized in the presence of two kinds of acidic amino
acids in order to investigate the effects of acidic amino acids on the morphology of hydroxyapatite
obtained by homogeneous precipitation and hydrothermal treating. The results of X-ray diffraction
analysis and microphotographs of transmission electron microscope showed that the morphology of
hydroxyapatite nanoparticles changed significantly only with aspartic acid. Hydroxyapatite synthesized
with aspartic acid showed smooth flake-like morphology at pH= 11 and flake-like morphology with
stripes at pH= 8. However, hydroxyapatite synthesized in the present of glutamic acid showed rod-like
morphology at both pH values. Variation in the morphology of nanoparticles could be consistent with the
difference in the affinity of amino acids binding at the hydroxyapatite crystal surface. The adsorption
process was revealed by computer simulation of molecular mechanics using energy minimizing method.
Abstract: The purpose of the work is to investigate the problems associated with utilization of purified fly
ash (PFA) as filler in polymer. The goal is to expand the application field of fly ash. The wet-collected fly
ash used in this study was sampled from Huaneng Dezhou Power Plant. Preparation of PFA and
composite fly ash (CFA) with nano-structured surface was described in detail. Experimental results show
that CFA with rough surface and high whiteness-value had successfully been prepared in
Ca(OH)2-H2O-CO2 system. The specific surface area of CFA was thrice or above higher than that of PFA
with 2.86 m2·g-1. The whiteness-value of CFA was increased to the range from 63.67 to 73.13 which is
more double than that of PFA with 33.54. Filling tests show that the mechanical properties of
CFA/PE(polyethylene) composites are superior to these of PFA/PE composites at the same filling ratio of
30/100. This means that change of CFA surface morphology increases contacting opportunities between
CFA and polymer matrix and improve the matching state between them when CFA is blended with PE.
The results show that CFA as filler appears to have good application, and yet, little serious research has
been conducted in the field.
Abstract: Silica xerogels were prepared by sol-gel process and non-supercritical drying. Two kinds of
reinforcements, SiC whisker and short carbon fiber (CF), were chosen to control the shrinkage during
drying process and improve the mechanical properties of xerogels. Microstructure and mechanical
properties of samples were examined. It was found that the addition of SiC whisker could greatly improve
the elastic modulus of silica xerogels, while short CF could prominently decrease the volume shrinkage
ratio but could not improve the elastic modulus. Analysis showed that the difference between the two
reinforcement mechanisms was caused by the interface and the size of the doped fiber and whisker.
Abstract: Monodispersed and nano-sized Ni powders were synthesized from aqueous Ni sulfate
hexahydrate (NiSO4· 6H2O) inside sucrose as a nonionic polymer network by using wet chemical
reduction process. The influence of a nonionic polymer network on the particle size of the Ni powders
were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM),
transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The Ni powders
obtained by adding of sucrose were nearly spherical in shape and seemed to be nano-sized, typically in
the range of 100 nm with not being agglomerated. As the sucrose content increased, the particle size
of Ni powders steeply decreased and reached the minimum value, however, the particle size increased
again with a further increase of sucrose content. This is believed to be due to the pore size of the
swollen polymer network. As a result, the particle size of the Ni powders prepared by the reduction
inside polymer network was strongly dependent of the sucrose content.
Abstract: The nano-size silver particles were prepared in polymer-protecting colloidal dispersion with
silver nitride as the raw material, hydrazine hydrate as the reduction reagent and polyvinyl pirrolidone
(PVP) as the protective solvent. The optimal conditions for the preparation process were studied
experimentally as well. The influences from main factors, such as Ag+ concentration and ratio of
hydrazine/AgNO3, on the particle size, appearance shape, particle aggregation condition and size
distribution of nano-silver particles were also investigated. The results showed that the size of Ag
particles prepared in this polymer-protecting system is less than 50 nm, and PVP can reduce the growing
tendency of nano-size silver particles. Meanwhile, the antibacterial dope loaded nano-silver particles
were prepared by wetting agent, dispersant, defoamer, etc. The antibacterial and bacteriostatic effects of
the dope with or without nano-silver particles were tested with bacilli as the tested bacteria. The
experiment results showed that the dope loaded nano-silver particles are of high practicality. Its antibacterial
ratio is also up to 91.9% in one hour when the added dosage of nano-silver is 0.02%.