Optical functionality of micro- and nanostructured silica surfaces prepared by a sol-gel phase separation method

2017 ◽  
Vol 622 ◽  
pp. 11-16
Author(s):  
Triin Kangur ◽  
Valter Kiisk ◽  
Ardi Loot ◽  
Martin Timusk ◽  
Martin Järvekülg
2012 ◽  
Vol 24 (3) ◽  
pp. 783-792 ◽  
Author(s):  
Paula Reemann ◽  
Triin Kangur ◽  
Martin Pook ◽  
Madis Paalo ◽  
Liis Nurmis ◽  
...  

Author(s):  
J. Tong ◽  
L. Eyring

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.


2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.


2005 ◽  
Vol 113 (1321) ◽  
pp. 634-636 ◽  
Author(s):  
Ryoji TAKAHASHI ◽  
Satoshi SATO ◽  
Toshiaki SODESAWA ◽  
Yuta HAGA ◽  
Masanari ISHIZUKI ◽  
...  

1990 ◽  
Vol 180 ◽  
Author(s):  
Y. Tsurita ◽  
K. Wada

ABSTRACTA new method for preparation of porous mixed oxide with SiO2 -ZrO2 -Na2O composition was investigated by heating the sol-gel derived SiO2 microsphere gel in the presence of ZrOCl2 and NaCI. Surface of the -products was composed of sponge-like structure, similar to the porous glasses manufactured by the phase separation method. Their pore volumes ranged from 1.0 to 1.5 cc/g(pore radius 100–lO00Å) and their pore distributions were sharp, with peak tops of about 450–600Å in radius.


Author(s):  
AMOL SHETE ◽  
PRIYANKA THORAT ◽  
RAJENDRA DOIJAD ◽  
SACHIN SAJANE

Objective: The objectives of present investigation were to prepare and evaluate proniosomes of neomycin sulphate (NS) by coacervation phase separation method by using sorbitan monostearate (span 60) and lecithin as a surfactant to increase the penetration through the skin and study the effect of concentration of the same. Methods: Proniosomes of neomycin sulphate (NS) were prepared by coacervation phase separation method by using span 60 and lecithin. The effect of concentration of span 60 and lecithin was studied by factorial design. The prepared proniosomes were converted to gel by using carbopol as a gelling agent. The prepared formulations were evaluated for entrapment efficiency, in vitro drug diffusion, in vitro antibacterial activity and in vivo skin irritation test etc. Results: All Formulation showed the percentage entrapment efficiency in the range 38.31±0.05% to 77.96±0.06%, good homogeneity and gel was easily spreadable with minimal of shear. Optimized formulation showed enhanced rate of diffusion in vitro, increase in zone of inhibition against staphylococcus aureus, no skin irritation and showed good stability. Conclusion: The results of present study indicates that proniosomal gel formulated by using combination of span 60, Lecithin, cholesterol can be used to enhance skin delivery of NS because of excellent permeation of drug. Developed proniosomal gel formulation was promising carrier for NS


2021 ◽  
pp. 119507
Author(s):  
Peipei Li ◽  
Roshni L. Thankamony ◽  
Xiang Li ◽  
Zhen Li ◽  
Xiaowei Liu ◽  
...  

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