scholarly journals Synthesis and Properties of Electrochemically Deposited Vertical Mesoporous Silica Thin Films

2015 ◽  
Vol 18 (3) ◽  
pp. 169-175
Author(s):  
Yuan Zhou ◽  
Qiming Liu ◽  
Ye Feng ◽  
Min Tan
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Ammonium Bromide ◽  
Silica Thin Films ◽  
Transmission Electron ◽  
Hydroxyl Ion ◽  
Mesoporous Film ◽  
Electrochemically Deposited ◽  
Cetyltrimethyl Ammonium

Electrochemical deposition was successfully used to prepare mesoporous silica thin films with highly ordered and vertically oriented pores. Tetraethyl orthosilicate was used as the inorganic silicon source and cetyltrimethyl ammonium bromide was the template. A negative potential was applied to the working electrode, which was initially immersed in collosol and then in hydroxyl at the electrode/solution interface. Hydroxyl ion served as the catalyst that promoted the polycondensation and self-assembly of the silicon precursor, as well as the formation of thin films with pores which are highly ordered and vertically oriented with respect to the panel.The pore arrangement of the mesoporous film was hexagonal, and its aperture was 2 nm to 3 nm. The verticality of the thin film pore was demonstrated through permeability and transmission electron microscopy analyses. The prepared mesoporous film possessed good optical amorphous antireflective property with ordered and vertically oriented pores.

Electrochemically assisted self-assembly of mesoporous silica thin films

2007 ◽  
Vol 6 (8) ◽  
pp. 602-608 ◽  
Author(s):  
A. Walcarius ◽  
E. Sibottier ◽  
M. Etienne ◽  
J. Ghanbaja
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Silica Thin Films

Development of 3-D Magnetic Nano-Arrays by Electrodeposition into Mesoporous Silica Films

2006 ◽  
Vol 961 ◽  
Author(s):  
Jason Manning ◽  
Roger Campbell ◽  
Martin Gerard Bakker ◽  
Xuefa Li ◽  
Dong Ryeol Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Magnetic Nanostructures ◽  
Grazing Incidence ◽  
Nano Particles ◽  
Silica Films ◽  
Silica Thin Films ◽  
Current Path ◽  
Wide Range

ABSTRACTThe development of periodic nanostructures fabricated by self-assembly of surfactants and block co-polymers has opened up the possibility of generating periodic magnetic nanostructures of types not accessible by self-assembly of nano-particles. The fabrication of mesoporous silica thin films around self-assembled block co-polymers is well established. Common structures for such films are SBA-15 which consists of hexagonal arrays of cylindrical pores and SBA-16 which has face centered arrays of spherical voids. These pores are connected by 1-2 nm thick flaws in the continuous silica phase producing an effectively continuous porous phase. After removal of the block co-polymer template, electrodeposition into the mesoporous silica thin films produces arrays of 5-10 nm diameter nano-wires and nano-particles. We have demonstrated that such materials can be fabricated on a wide range of metal substrates. Characterization by Scanning Electron Microscopies shows that the mesoporous silica is well ordered over micron scale areas. Grazing Incidence Small Angle X-ray Scattering (GISAXS) studies shows diffraction spots, consistent with the entire film being well ordered. GISAXS also shows that the mesoporous silica films survive removal of the template and electrodeposition of nickel and cobalt into the mesoporous silica films. Such films are of interest for their magnetic properties, as the nanophase and scale can be independently varied. Further, the presence of nanowires inside an insulator suggests that these films might also be of interest as the current confining element for Confined Current Path-Current Perpendicular to Plane GMR sensors.

Thermal Conductivity of Cubic Mesoporous Silica Thin Films

2007 ◽  
Author(s):  
Soojung C. Hur ◽  
Laurent Pilon ◽  
Adam Christensen ◽  
Samuel Graham
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Room Temperature ◽  
Mean Free Path ◽  
Fused Silica ◽  
Silica Thin Films ◽  
The Cross ◽  
Cubic Mesoporous

This paper reports, for the first time, the cross-plane thermal conductivity of highly ordered cubic mesoporous silica thin films with porosity of 31% and thickness ranging between 200 and 500 nm. The mesoporous thin films are synthesized based on evaporation induced self-assembly process. The pores are spherical with average inter-pore spacing and pore diameter equal to 5.95 nm and 5 nm, respectively. The thermal conductivity is measured at room temperature using the 3ω method. The experimental setup and the associated analysis are validated by comparing the thermal conductivity measurements for the silicon substrate and for high quality thermal oxide thin films with data reported in the literature. The cross-plane thermal conductivity of the synthesized mesoporous silica thin films does not strongly depend on film thickness due to the reduction in phonon mean free path caused by the presence of nanopores. The average thermal conductivity is 0.61 ± 0.011 W/mK, which is 56% lower than that of bulk fused silica at room temperature.

Photo-orientation of Mesoporous Silica Thin Films on Photocrosslinkable Polymer Films

2005 ◽  
Vol 17 (8) ◽  
pp. 1035-1039 ◽  
Author(s):  
H. Fukumoto ◽  
S. Nagano ◽  
N. Kawatsuki ◽  
T. Seki
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Polymer Films ◽  
Silica Thin Films
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