Properties of Transparent Silica Gel - Pmma Composites

1988 ◽  
Vol 132 ◽  
Author(s):  
Edward J. A. Pope ◽  
Minuo Asami ◽  
John D. Mackenzie
Keyword(s):  
Polymer Composites ◽  
Silica Gel ◽  
Porous Silica ◽  
Silica Gels ◽  
New Class ◽  
Transparent Composites ◽  
Organic Monomer

ABSTRACTTransparent silica gel - polymer composites have been prepared by the impregnation of porous silica gels with fluid organic monomer followed by in situ polymerization. These materials constitute an entirely new class of transparent composites.

Transparent silica gel–PMMA composites

1989 ◽  
Vol 4 (4) ◽  
pp. 1018-1026 ◽  
Author(s):  
E. J. A. Pope ◽  
M. Asami ◽  
J. D. Mackenzie
Keyword(s):  
Compressive Strength ◽  
Refractive Index ◽  
Polymer Composites ◽  
Silica Gel ◽  
Vickers Hardness ◽  
Modulus Of Rupture ◽  
New Class ◽  
Abrasion Rate ◽  
Organic Monomer

Transparent silica gel–polymer composites have been prepared by the impregnation of porous gels with organic monomer and polymerization in situ. The relative amount of each phase was adjusted by varying the porosity of the silica gel prior to impregnation. These materials constitute a new class of transparent composites. Properties, such as density, refractive index, modulus of rupture, compressive strength, abrasion rate, and Vickers hardness, have been measured over the compositional range of 100% silica to 100% polymethyl methacrylate (PMMA).

scholarly journals Maleimide Functionalized Siloxane Resins

1999 ◽  
Vol 576 ◽  
Author(s):  
R. M. Shaltout ◽  
D. A. Loy ◽  
D. R. Wheeler
Keyword(s):  
Diels Alder ◽  
Inorganic Filler ◽  
Side Reactions ◽  
Inorganic Component ◽  
New Class ◽  
Silicon Alkoxides ◽  
Filler Phase ◽  
Alder Adduct ◽  
Organic Monomer

ABSTRACTIn-situ filling through hydrolysis and condensation of silicon alkoxides dissolved into polymers has been utilized to generate nanocomposites in which the filler phase can be intimately associated with the polymer on relatively small length scales. One problem of the method has been achieving useful fill volumes without bulk phase separation of the growing inorganic component from the polymer. In this paper, we describe the preparation of a new class of nanocomposite materials in which the inorganic filler phase is pre-assembled before copolymerization with an organic monomer. Maleimide monomers, prepared from alkoxysilylpropyl amines and maleic anhydride, were protected against side reactions by forming the oxonorbornene Diels-Alder adduct with furan. The monomers were then reacted under solgel conditions to form oligomers or polymers making up the filler phase. The material was activated by thermal deprotection of the maleimide and reacted with organic monomers or polymers to form the filled nanocomposite.

In situ measurement of drug transport in porous silica gel

2018 ◽  
Vol 260 ◽  
pp. 17-23 ◽  
Author(s):  
Jaypee Quiño ◽  
Katja Franke ◽  
Mihaela Ivanova ◽  
Sabine Kareth ◽  
Marcus Petermann ◽  
...  
Keyword(s):  
Silica Gel ◽  
Drug Transport ◽  
Porous Silica ◽  
In Situ Measurement ◽  
Porous Silica Gel

scholarly journals Effect of Hydrophobic Silica Nanochannel Structure on the Running Speed of a Colloidal Damper

2021 ◽  
Vol 11 (15) ◽  
pp. 6808
Author(s):  
Gengbiao Chen ◽  
Zhiwen Liu
Keyword(s):  
Fractal Dimension ◽  
Silica Gel ◽  
Fractal Theory ◽  
Percolation Model ◽  
Silica Gels ◽  
Practical Significance ◽  
Running Speed ◽  
Fractal Percolation ◽  
Micropore Structure ◽  
Hydrophobic Silica

A colloidal damper (CD) can dissipate a significant amount of vibrations and impact energy owing to the interface power that is generated when it is used. It is of great practical significance to study the influence of the nanochannel structure of hydrophobic silica gel in the CD damping medium on the running speed of the CD. The fractal theory was applied to observe the characteristics of the micropore structure of the hydrophobic silica gel by scanning electron microscopy (SEM), the primary particles were selected to carry out fractal analysis, and the two-dimensional fractal dimension of the pore area and the tortuous fractal dimension of the hydrophobic silica gel pore structure were calculated. The fractal percolation model of water in hydrophobic silica nanochannels based on the slip theory could thus be obtained. This model revealed the relationship between the micropore structure parameters of the silica gel and the running speed of the CD. The CD running speed increases with the addition of grafted molecules and the reduction in pore size of the silica gel particles. Continuous loading velocity testing of the CD loaded with hydrophobic silica gels with different pore structures was conducted. By comparing the experimental results with the calculation results of the fractal percolation model, it was determined that the fractal percolation model can better characterize the change trend of the CD running velocity for the first loading, but the fractal dimension was changed from the second loading, caused by the small amount of water retained in the nanochannel, leading to the failure of fractal characterization.

Relaxation of excitations in porous silica gels

1988 ◽  
Vol 128 (1) ◽  
pp. 199-207 ◽  
Author(s):  
J.M. Drake ◽  
P. Levitz ◽  
S.K. Sinha ◽  
J. Klafter
Keyword(s):  
Porous Silica ◽  
Silica Gels

Bioencapsulation in Sol-Gel Glasses

1998 ◽  
Vol 519 ◽  
Author(s):  
L. Bergogne ◽  
S. Fennouh ◽  
J. Livage ◽  
C. Roux
Keyword(s):  
Sol Gel ◽  
Porous Silica ◽  
Silica Matrix ◽  
Whole Cells ◽  
The Past ◽  
Wide Range ◽  
Activity Of Enzymes ◽  
Gel Glasses ◽  
Micro Organisms

AbstractBioencapsulation in sol-gel materials has been widely studied during the past decade. Trapped species appear to retain their bioactivity in the porous silica matrix. Small analytes can diffuse through the pores allowing bioreactions to be performed in-situ, inside the sol-gel glass. A wide range of biomolecules and micro-organisms have been encapsulated. The catalytic activity of enzymes is used for the realization of biosensors or bioreactors. Antibody-antigen recognition has been shown to be feasible within sol-gel matrices. Trapped antibodies bind specifically the corresponding haptens and can be used for the detection of traces of chemicals. Even whole cells are now encapsulated without any alteration of their cellular organization. They can be used for the production of chemicals or as antigens for immunoassays.

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