Chemical Sensors Based on Surface-Modified Sol-Gel-Coated Infrared Waveguides

1998 ◽  
Vol 52 (1) ◽  
pp. 119-122 ◽  
Author(s):  
Ling Han ◽  
Thomas M. Niemczyk ◽  
Yunfeng Lu ◽  
Gabriel P. Lopez
Keyword(s):  
Aqueous Solutions ◽  
Infrared Spectra ◽  
Sol Gel ◽  
Porous Silica ◽  
Hydrophobic Surface ◽  
Silica Film ◽  
Porous Silica Film ◽  
Surface Modified ◽  
Infrared Waveguides ◽  
Organic Analytes

Attenuated total reflectance sampling, or waveguide sampling, is commonly used to obtain infrared spectra of aqueous solutions. The detection limits achieved for the determination of organic analytes in aqueous solutions using waveguide sampling are limited by the strong water absorption features and relatively small effective sample thickness due to the short penetration depth of the evanescent wave into the sample. Sol-gel processing has been used to produce a porous silica film on the surface of an infrared waveguide. The surface of the sol-gel film was modified with a silanizing reagent to produce a hydrophobic surface. The resulting waveguide was used to obtain infrared spectra from samples of benzonitrile in water. The benzonitrile spectral features obtained with the modified waveguide are enhanced by more than a factor of 103 when compared with those obtained with an unmodified waveguide.

Superhydrophobic Surface Modified by Sol-Gel Silica Nanoparticle Coating

2019 ◽  
Vol 960 ◽  
pp. 155-160
Author(s):  
Xiao Xing Zhang ◽  
Yan Yan Wang ◽  
Liang Gu ◽  
Zhi Yong Xu ◽  
Yan Hua Liu ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Sol Gel ◽  
Silica Nanoparticle ◽  
Hydrophobic Surface ◽  
Cost Effective ◽  
Silica Film ◽  
Water Contact ◽  
Superhydrophobic Silica ◽  
Surface Modified ◽  
Surface Fabrication

We reported a superhydrophobic silica-coated surface with a water contact angle of 160° with a 4 μL water droplet, and transparency of 70-86% in the wavelength range of 380-800 nm. The silica film was synthesized at room temperature (22 °C) using sol-gel process by a simple, cost-effective and uniform spin-coating by mixing silicon dioxide sol-gel with γ-(2, 3-epoxypropyloxy) propyltrimethoxysilane (KH-560). The durability of the coating could be effectively enhanced by controlling the ratio of KH-560 and modified silicon dioxide sol-gel. It was believed that this process that we used can hold a great potential in super-hydrophobic surface fabrication.

Comparative Studies of Ultra Low-κ Porous Silica Films with 2-D Hexagonal and Disordered Pore Structures

2004 ◽  
Vol 812 ◽  
Author(s):  
Nobutoshi Fujii ◽  
Kazuhiro Yamada ◽  
Yoshiaki Oku ◽  
Nobuhiro Hata ◽  
Yutaka Seino ◽  
...  
Keyword(s):  
Pore Structure ◽  
Nonionic Surfactants ◽  
Porous Silica ◽  
Silica Film ◽  
X Ray Diffraction ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Porous Silica Film ◽  
Diffraction Peaks

AbstractPeriodic 2-dimensional (2-D) hexagonal and the disordered pore structure silica films have been developed using nonionic surfactants as the templates. The pore structure was controlled by the static electrical interaction between the micelle of the surfactant and the silica oligomer. No X-ray diffraction peaks were observed for the disordered mesoporous silica films, while the pore diameters of 2.0-4.0 nm could be measured by small angle X-ray scattering spectroscopy. By comparing the properties of the 2-D hexagonal and the disordered porous silica films which have the same porosity, it is found that the disordered porous silica film has advantages in terms of the dielectric constant and Young's modulus as well as the hardness. The disordered porous silica film is more suitable for the interlayer dielectrics for ULSI.

Gas-Sensitive Optical Absorption of Ultrafine Silver Particles Dispersed in a Porous Silica Film

1988 ◽  
Vol 27 (Part 2, No. 2) ◽  
pp. L164-L166 ◽  
Author(s):  
Akihisa Yanase ◽  
Hiroshi Komiyama ◽  
Kazunobu Tanaka
Keyword(s):  
Optical Absorption ◽  
Porous Silica ◽  
Silica Film ◽  
Silver Particles ◽  
Porous Silica Film

scholarly journals The roles of hydrophobic group on the surface of ultra low dielectric constant porous silica film during thermal treatment

2007 ◽  
Vol 515 (18) ◽  
pp. 7275-7280 ◽  
Author(s):  
Jen-Tsung Luo ◽  
Wen-Fa Wu ◽  
Hua-Chiang Wen ◽  
Ben-Zu Wan ◽  
Yu-Ming Chang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Thermal Treatment ◽  
Porous Silica ◽  
Silica Film ◽  
Low Dielectric Constant ◽  
Hydrophobic Group ◽  
Low Dielectric ◽  
Porous Silica Film

A novel fabrication of meso-porous silica film by sol-gol of TEOS

2004 ◽  
Vol 5 (4) ◽  
pp. 422-427 ◽  
Author(s):  
Ming-zhi Yin ◽  
Xi Yao ◽  
Liang-ying Zhang
Keyword(s):  
Porous Silica ◽  
Silica Film ◽  
Porous Silica Film

Structure control of periodic porous silica film for low-k application

2002 ◽  
Author(s):  
Kazuhiro Yamada ◽  
Yoshiaki Oku ◽  
Nobuhiro Hata ◽  
Shozo Takada ◽  
Takamaro Kikkawa
Keyword(s):  
Porous Silica ◽  
Silica Film ◽  
Structure Control ◽  
Porous Silica Film ◽  
Low K

A Novel Organosiloxane Vapor Annealing Process for Improving Elastic Modulus of Porous Low-k Films

2004 ◽  
Vol 812 ◽  
Author(s):  
Kazuo Kohmura ◽  
Shunsuke Oike ◽  
Masami Murakami ◽  
Hirofumi Tanaka ◽  
Syozo Takada ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Mechanical Strength ◽  
Porous Silica ◽  
Thermal Desorption Spectroscopy ◽  
Silica Film ◽  
Low Dielectric ◽  
Porous Silica Film ◽  
Vapor Annealing ◽  
Ft Ir ◽  
Low K

AbstractA novel organosiloxane-vapor-annealing method has been developed for improving the mechanical strength of porous silica films with a low dielectric constant. Treatment of a porous silica film with 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) under atmospheric nitrogen above 350 °C significantly enhanced the mechanical strength (i.e., elastic modulus and hardness) of the film. Results of Fourier transform infrared spectroscopy (FT-IR) and thermal desorption spectroscopy (TDS) suggested the formation of cross-linked poly(TMCTS) network on the porous silica internal wall surfaces by the TMCTS treatment. Such TMCTS cross-linked network is thought to enhance the mechanical strength of the low-k film.

Photo-Induced Growth of Low Dielectric Constant Porous Silica Film at Room Temperature

2000 ◽  
Vol 612 ◽  
Author(s):  
Jun-Ying Zhang ◽  
Ian W. Boyd
Keyword(s):  
Dielectric Constant ◽  
Substrate Temperature ◽  
Room Temperature ◽  
Sol Gel ◽  
Porous Silica ◽  
Silica Film ◽  
Electrical Measurements ◽  
Processing Times ◽  
Low Dielectric ◽  
Stretching Vibration

AbstractWe report low temperature (25-200°C) photo-assisted sol-gel processing for the formation of porous silicon dioxide films on Si (100) substrates using 172 nm radiation from an excimer lamp. The effects of substrate temperature and irriadation time on the properties of the films formed have been studied using ellipsometry, Fourier transform infrared spectroscopy (FTIR), and electrical measurements. The FTIR spectra revealed the presence of a Si-O-Si stretching vibration peak at 1070 cm-1 after UV irradiation at 200°C. This is similar to that recorded for oxides grown by thermally oxidation of silicon at temperatures between 600-1000°C. Capacitance measurements indicated that the dielectric constant values of the films, found to be between 1.7-3.3, strongly depended on the substrate temperature during irradiation. Dielectric constant values as low as 1.7 were readily achievable at room temperature. These results show that the photochemical induced effects initiated by the UV radiation enable both reduced processing times and reduced processing temperatures to be used.

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