Aggregation of Silica Nanoparticles in Sol–Gel Processes to Create Optical Coatings with Controllable Ultralow Refractive Indices

2020 ◽  
Vol 12 (14) ◽  
pp. 16887-16895
Author(s):  
Fangting Chi ◽  
Yiyang Zeng ◽  
Cheng Liu ◽  
Dan Liang ◽  
Yuanli Li ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Sol Gel ◽  
Optical Coatings ◽  
Refractive Indices

scholarly journals Selective porous gates made from colloidal silica nanoparticles

2015 ◽  
Vol 6 ◽  
pp. 2105-2112 ◽  
Author(s):  
Roberto Nisticò ◽  
Paola Avetta ◽  
Paola Calza ◽  
Debora Fabbri ◽  
Giuliana Magnacca ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Spin Coating ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Chemical Species ◽  
Solvent System ◽  
Porous Films ◽  
Nanoporous Films ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Highly selective porous films were prepared by spin-coating deposition of colloidal silica nanoparticles on an appropriate macroporous substrate. Silica nanoparticles very homogenous in size were obtained by sol–gel reaction of a metal oxide silica precursor, tetraethyl orthosilicate (TEOS), and using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) copolymers as soft-templating agents. Nanoparticles synthesis was carried out in a mixed solvent system. After spin-coating onto a macroporous silicon nitride support, silica nanoparticles were calcined under controlled conditions. An organized nanoporous layer was obtained characterized by a depth filter-like structure with internal porosity due to interparticle voids. Permeability and size-selectivity were studied by monitoring the diffusion of probe molecules under standard conditions and under the application of an external stimulus (i.e., electric field). Promising results were obtained, suggesting possible applications of these nanoporous films as selective gates for controlled transport of chemical species in solution.

Natural Rubber Reinforced with Silica Nanoparticles Extracted from Jasmine and Riceberry Rice Husk Ashes

2018 ◽  
Vol 936 ◽  
pp. 31-36 ◽  
Author(s):  
Wichudaporn Seangyen ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Silica Nanoparticles ◽  
Rice Husk ◽  
Sol Gel ◽  
Rubber Matrix ◽  
Reinforcing Fillers ◽  
Rubber Nanocomposites ◽  
Jasmine Rice ◽  
20 Nm

Silica nanoparticles were synthesized by rice husk ash (RHA) produced from jasmine rice husk and riceberry rice husk via sol-gel method for the use as reinforcing fillers in natural rubber (NR). The obtained silica nanoparticles are spherical in shape and the particle sizes were observed to be in the 10-20 nm range with uniformly size distribution. The surface of silica nanoparticles was treated with a silane coupling agent confirmed by FTIR. The treated silica nanoparticles were then incorporated into NR and vulcanized with electron beam irradiation. The rubber nanocomposites with silica nanoparticles, produced from jasmine rice husk and riceberry rice husk, resulted in higher mechanical properties (tensile strength and modulus) than neat rubber vulcanizate. The modified rubber vulcanizates revealed rougher surface with tear lines as compared to the neat rubber vulcanizates, indicating the improved strength. Interestingly, the rubber nanocomposites with silica nanoparticles from jasmine rice husk showed higher tensile strength and modulus than silica nanoparticles produced from riceberry rice husk. The micrographs indicated better dispersion of NR composites with jasmine rice husk which leads to a strong interaction between silica nanoparticles and rubber matrix, thereby improving the strength.

Preparation of superhydrophobic silica nanoparticles by microwave assisted sol–gel process

2011 ◽  
Vol 61 (1) ◽  
pp. 8-13 ◽  
Author(s):  
A. Santiago ◽  
A. González ◽  
J. J. Iruin ◽  
M. J. Fernández-Berridi ◽  
L. Irusta
Keyword(s):  
Silica Nanoparticles ◽  
Sol Gel ◽  
Microwave Assisted ◽  
Sol Gel Process ◽  
Superhydrophobic Silica

scholarly journals Large Pore Mesoporous Silica and Organosilica Nanoparticles for Pepstatin A Delivery in Breast Cancer Cells

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 332 ◽  
Author(s):  
Saher Rahmani ◽  
Jelena Budimir ◽  
Mylene Sejalon ◽  
Morgane Daurat ◽  
Dina Aggad ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Cancer Cells ◽  
Cathepsin D ◽  
Breast Cancer Cells ◽  
Potent Inhibitor ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Pepstatin A

(1) Background: Nanomedicine has recently emerged as a new area of research, particularly to fight cancer. In this field, we were interested in the vectorization of pepstatin A, a peptide which does not cross cell membranes, but which is a potent inhibitor of cathepsin D, an aspartic protease particularly overexpressed in breast cancer. (2) Methods: We studied two kinds of nanoparticles. For pepstatin A delivery, mesoporous silica nanoparticles with large pores (LPMSNs) and hollow organosilica nanoparticles (HOSNPs) obtained through the sol–gel procedure were used. The nanoparticles were loaded with pepstatin A, and then the nanoparticles were incubated with cancer cells. (3) Results: LPMSNs were monodisperse with 100 nm diameter. HOSNPs were more polydisperse with diameters below 100 nm. Good loading capacities were obtained for both types of nanoparticles. The nanoparticles were endocytosed in cancer cells, and HOSNPs led to the best results for cancer cell killing. (4) Conclusions: Mesoporous silica-based nanoparticles with large pores or cavities are promising for nanomedicine applications with peptides.

Preparation and Characterization of Paclitaxel Imprinted Silica Nanoparticles

2011 ◽  
Vol 399-401 ◽  
pp. 1894-1897
Author(s):  
Jian Hua Li ◽  
Zong Jian Zheng ◽  
Shao Ping Fu ◽  
Jing Bo Zhu
Keyword(s):  
Silica Nanoparticles ◽  
Dissociation Constants ◽  
Sol Gel ◽  
Scatchard Analysis ◽  
Binding Properties ◽  
Imprinted Polymers ◽  
Sol Gel Process ◽  
Equilibrium Dissociation Constants ◽  
Equilibrium Dissociation

Highly selective molecularly imprinted layer-coated silica nanoparticles for paclitaxel were synthesized by molecular imprinting technique with a sol–gel process on the supporter of silica nanoparticles. The morphology of the obtained polymers was characterized by scanning electron microscopy (SEM). The binding properties of the imprinted polymers were evaluated through the equilibrium rebinding experiments. Scatchard analysis revealed that two classes of binding sites were formed in the imprinted polymers with equilibrium dissociation constants of 0.0509 g•L-1and 0.0094 g•L-1, respectively. Paclitaxel and its analogue were employed for selectivity tests. The results indicated that the imprinted polymers exhibited good selectivity and specificity toward paclitaxel.

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