scholarly journals Polystyrene-block-poly(ethylene oxide) copolymers as templates for stacked, spherical large-mesopore silica coatings: dependence of silica pore size on the PS/PEO ratio

2016 ◽  
Vol 7 ◽  
pp. 1454-1460 ◽  
Author(s):  
Roberto Nisticò ◽  
Giuliana Magnacca ◽  
Sushilkumar A Jadhav ◽  
Dominique Scalarone
Keyword(s):  
Ethylene Oxide ◽  
Pore Size ◽  
Silicon Oxide ◽  
Sol Gel ◽  
High Porosity ◽  
Silica Films ◽  
Systematic Analysis ◽  
Silica Coatings ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Large-mesopore silica films with a narrow pore size distribution and high porosity have been obtained by a sol–gel reaction of a silicon oxide precursor (TEOS) and using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) copolymers as templates in an acidic environment. PS-b-PEO copolymers with different molecular weight and composition have been studied in order to assess the effects of the block length on the pore size of the templated silica films. The changes in the morphology of the porous systems have been investigated by transmission electron microscopy and a systematic analysis has been carried out, evidencing the dependence between the hydrophilic/hydrophobic ratio of the two polymer blocks and the size of the final silica pores. The obtained results prove that by tuning the PS/PEO ratio, the pore size of the templated silica films can be easily and finely predicted.

Electrical and Electrochromic Characterization of Poly(ethylene Oxide)/Molybdenum Doped Vanadium Pentoxide Films

2013 ◽  
Vol 785-786 ◽  
pp. 771-774
Author(s):  
Ai Ping Jin ◽  
Wen Chen ◽  
Quan Yao Zhu
Keyword(s):  
Ethylene Oxide ◽  
Vanadium Pentoxide ◽  
Hydrothermal Reaction ◽  
Sol Gel ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Transmission Spectra ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The hybrid guest-host nanocomposite films based on poly (ethylene oxide) (PEO) and molybdenum doped vanadium pentoxide (V0.975Mo0.025)2O5nH2O were prepared by sol-gel and hydrothermal reaction via a two-part process. The electrical properties along and across V-O layers have been evaluated. The results indicate that the proper amount of PEO can increase the electrical conductivity of the films. The electrochromism of the films were investigated by cyclic voltammetry, the ex-situ transmission spectra and photographs. The films display a reversible multichromism (orangegreenbluebrown) upon Li+ion insertion/extraction.

Iron Oxide – Doped Mesostructured Silica Films

2004 ◽  
Vol 847 ◽  
Author(s):  
Ralf Supplit ◽  
Nicola Hüsing ◽  
Christina Fritscher ◽  
Patrycja Jakubiak ◽  
Vadim G. Kessler ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Ethylene Oxide ◽  
Grazing Incidence ◽  
Molar Ratio ◽  
Silica Films ◽  
Mesostructured Silica ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Propylene ◽  
Nanocomposite Structures

ABSTRACTPoly(ethylene oxide)—poly(propylene oxide)—poly(ethylene oxide) (PEO-PPO-PEO) was reacted with iron ethoxide in a molar ratio of 1:2. This modified surfactant was used as a template for the synthesis of mesostructured, nanocomposite iron oxide-silica films and powders. Grazing incidence (GI)-SAXS measurements of the films showed that depending on the concentration of the surfactant wormhole-like, 2d-centered rectangular, orthorhombic and lamellar nanocomposite structures were formed. Interestingly, the mesoscopic ordering of the orthorhombic and 2d-centered rectangular pore structure is retained even after calcination at 1000 °C for one hour. The influence of heat treatment on the mesostructure was investigated by GI-SAXS, TEM and N2-sorption measurements.

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