Preparation and Properties of PVC-Silica Composites using Different Catalysts Via Sol-Gel Process

1999 ◽  
Vol 576 ◽  
Author(s):  
Khan M. Asif ◽  
M.I. Sarwar ◽  
Z. Ahmad

Novel micro-composites from Polyvinyl chloride (PVC) and silica were prepared using sol-gel technique. Different catalysts were used for the in-situ generation of silica network from tetraethylorthosilicate (TEOS) in the PVC matrix. Thin transparent films containing various proportions of silica in PVC were cast by the solvent elution technique. Mechanical properties of these films were studied. The results showed an increase in the value of Young's modulus and strain at rupture by the addition of small amount of silica in PVC. However, the stress at yields point and stress at rupture decreased with the addition of silica contents. Scanning electron microscopy (SEM-EDAX) studies were also performed on these samples.

1999 ◽  
Vol 576 ◽  
Author(s):  
Brigitta M. Baugher ◽  
Duane A. Schneider ◽  
Douglas A. Loy ◽  
Kamyar Rahimian

ABSTRACTPolymerization of organotrialkoxysilanes is a convenient method for introducing organic functionality into hybrid organic-inorganic materials. However, not much is known about the effects of the organic substituent on the porosity of the resulting xerogels. In this study, we prepared a series of polysilsesquioxane xerogels from organotrialkoxysilanes, RSi(OR′)3, with different organic groups (R = H, Me, Et, dodecyl, hexadecyl, octadecyl, vinyl, chloromethyl, cyanoethyl). Polymerizations of the monomers were carried out under a variety of conditions, varying monomer concentration, type of catalyst, and alkoxide substituent. The effect of the organic substituent on the sol-gel process was often dramatic. In many cases, gels were formed only at very high monomer concentration and/or with only one type of catalyst. All of the gels were processed as xerogels and characterized by scanning electron microscopy and nitrogen sorption porosimetry to evaluate their pore structure.


1998 ◽  
Vol 541 ◽  
Author(s):  
M. Linnik ◽  
O. Wilson ◽  
A. Christou

AbstractThe preparation and characterization of thick PLZT films for spatial phase modulator applications are reported. Films were fabricated on LSCO/LAO substrates by a sol-gel technique using multiple heat-treatment parameters. The crystal quality of PLZT 9/65/35 films was investigated by X-ray diffraction and scanning electron microscopy.


2015 ◽  
Vol 1091 ◽  
pp. 15-18 ◽  
Author(s):  
V.A. Shmatko ◽  
T.N. Myasoedova ◽  
G.E. Yalovega

In the paper the SiO2CuOx and SiO2(CuOxSnOy) thin films were deposited from the alcoholic solutions employing the sol-gel technique. The films were characterized by means of SEM (scanning electron microscopy) and 2p x-ray photoelectron spectroscopy (XPS). The SEM studies found the grain shape changes from flower-like to regular shaped inorganic agglomerates as result of adding the SnCl4 into the sol. The X-ray photoelectron spectroscopy (XPS) studies showed the presence both CuO and CuO2 phases and formation of a double CuSiO3 oxide phase.


2012 ◽  
Vol 531-532 ◽  
pp. 614-617 ◽  
Author(s):  
Gunawan ◽  
I. Sopyan ◽  
A. Naqshbandi ◽  
S. Ramesh

Biphasic calcium phosphate powders doped with zinc (Zn-doped BCP) were synthesized via sol-gel technique. Different concentrations of Zn have been successfully incorporated into biphasic calcium (BCP) phases namely: 1%, 2%, 3%, 5%, 7%, 10% and 15%. The synthesized powders were calcined at temperatures of 700-900°C. The calcined Zn-doped BCP powders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential and thermogravimetric analysis (TG/DTA) and field-emission scanning electron microscopy (FESEM). X-ray diffraction analysis revealed that the phases present in Zn-doped are hydroxyapatite, β- TCP and parascholzite. Moreover, FTIR analysis of the synthesized powders depicted that the bands of HPO4 increased meanwhile O-H decreased with an increase in the calcination temperature. Field emission scanning electron microscopy (FESEM) results showed the agglomeration of particles into microscale aggregates with size of the agglomerates tending to increase with an increase in the dopant concentration.


2012 ◽  
Vol 1424 ◽  
Author(s):  
Russell J. Bailey ◽  
Beatriz Cortes-Ballesteros ◽  
Hao Zhang ◽  
Congwei Wang ◽  
Asa H. Barber

ABSTRACTThe mechanical properties of individual electrospun polystyrene fibers with sub-micron diameters were measured using a combination of atomic force microscopy (AFM) and scanning electron microscopy (SEM). The strain to failure of the electrospun fibers was observed to increase as the fiber diameter decreased. This size dependent mechanical behavior in individual electrospun polystyrene fibers indicates a suppression of localized failure and a shift away from crazing that is dominant in bulk samples.


2016 ◽  
Vol 850 ◽  
pp. 742-747
Author(s):  
Xiang Zhang ◽  
Ping Yun Li ◽  
Xiao De Guo ◽  
Ting Yan

Ultrafine alumina powders were synthesized through pyrocatechol and resorcinol mediated sol-gel process. Aluminum nitrate was applied as the Al source and PVP was the dispersant. X-ray diffraction (XRD) study displayed that γ-Al2O3 powders formed in the range of 800-900 °C, and then γ-Al2O3 transformed to α-Al2O3 at higher temperatures, pure α-Al2O3 powders could be obtained at 1000 °C by using resorcinol as organic monomer. The results of transmission electron microscopy (TEM) revealed that Al2O3 nanoparticles with γ crystalline phase had grain sizes in the range of 5-40 nm. Scanning electron microscopy (SEM) observation displayed that the morphology of the prepared α-Al2O3 powders had aggregated bodies formed by Al2O3 grains in the range of 0.2-0.5μm. These results provide a new way of preparation of alumina powders.


2008 ◽  
Vol 23 (S1) ◽  
pp. S75-S80
Author(s):  
A. T. Adorno ◽  
R. A. G. Silva ◽  
V. H. S. Utuni

The pearlitic reaction in Cu-10wt%Al alloy with additions of 4, 6, 8, and 10wt%Ag was studied using scanning electron microscopy, energy dispersive X-ray microanalysis, in situ X-ray diffractometry, and microhardness measurements. The results indicated that the presence of Ag changes the pearlitic phase microstructure and its mechanical properties, because of the influence of Ag in the pearlitic phase growth mechanism.


2015 ◽  
Vol 814 ◽  
pp. 39-43 ◽  
Author(s):  
Lei Lei Chen ◽  
Hong Mei Deng ◽  
Ke Zhi Zhang ◽  
Ling Huang ◽  
Jian Liu ◽  
...  

Cu2MnSnS4 thin film was successfully prepared by a sol-gel technique on soda lime glass substrate from metal salts and thiourea. The structural and morphological properties of the fabricated film were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and atomic force microscopy. The combination of the X-ray diffraction results and Raman spectroscopy reveal that this obtained layer is composed by Cu2MnSnS4 phase and has a stannite structure with preferential orientation along the (112) direction. The scanning electron microscopy and atomic force microscopy results show that the synthesized thin film is smooth and compact without any visible cracks or pores. The band gap of the Cu2MnSnS4 thin film is about 1.29 eV determined by the UV-vis-NIR absorption spectra measurement, which indicates it has potential applications in solar cells.


2010 ◽  
Vol 17 (01) ◽  
pp. 59-62 ◽  
Author(s):  
YOUNG-JAE KO ◽  
JONG KYU LEE ◽  
MIN-CHEOL CHU ◽  
DONG-SIK BAE

Y 2 SiO 5: Ce 3+ particles was synthesized by sol–gel process. In all samples treated at 1100°C, monoclinic X 1 phase for all cerium concentration. Luminescence spectra shows broad Ce 3+ luminescence in Y 2 SiO 5 host, which picks around 450 nm. The synthesized and calcined powders were characterized by thermogravimetry-differential scanning calorimeter (TG-DSC), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and photoluminescence spectra (PL).


2011 ◽  
Vol 287-290 ◽  
pp. 613-617 ◽  
Author(s):  
Li Peng Zhang ◽  
Xian Jin Yu ◽  
Zhi Wei Ge ◽  
Yun Hui Dong ◽  
Dang Gang Li

Ca3Co4O9 and Ca3-xLaxCo4O9 powders were prepared by sol-gel process. The Ca-Co-O thermoelectric material ceramics were prepared. The ceramics materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microstructure and thermoelectric properties of ceramics were researched. The results indicate that the crystal of Ca3-xLaxCo4O9 with La adding growth ideally, the material had high density and low pore rate. The Ca3-xLaxCo4O9 ceramics contain directional array plate-shaped grains with layered structure. The thermoelectric properties of Ca3-xLaxCo4O ceramics were excellent. There were high Seebeck coefficient and high electrical conductivity for Ca3-xLaxCo4O9 ceramics. The power factor increased with temperature increasing.


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