EPR, optical, infrared and Raman spectral studies of Actinolite mineral

Gopal, N.O.; Narasimhulu, K.; Rao, J.L.

doi:10.1016/j.saa.2003.12.021

Cited by 72 publications

(44 citation statements)

References 29 publications

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“…The presence of the silanol groups were confirmed by the band centred about 960 cm -1 , which is associated with the stretching mode of the Si-OH groups [24]. The symmetric stretching vibrations of Si-O-Si appear at 800 cm −1 and 680 cm −1 [20,21,25] and its bending mode appears at 467-458 cm −1 [21,24,26,27].…”

Section: Ft-ir Analysismentioning

confidence: 93%

Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid

Putz

Len

Ianăși

et al. 2016

Korean J. Chem. Eng.

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2Mesoporous silica matrices have been prepared via classic acid catalyzed and sono-catalyzed sol-gel routes. Tetramethoxysilan (TMOS) and methyl-trimethoxysilane (MTMS) were used as silica precursors, and N-butyl-3-methylpyridinium tetrafluoroborate ([bmPy][BF4]) was employed as cosolvent and pore template. The ionic liquid (IL) to silica mole ratio was varied between 0.007 and 0.07. Nitrogen adsorption-desorption and small-angle neutron scattering measurements have been used to characterize the obtained materials. The ionic liquid played the role of catalyst that affected the formation of the primary xerogel particles, and changed the porosity of the materials. Ultrasound treatment resulted in microstructure change on the level of the colloid particle aggregates. In comparison with IL containing xerogels, the IL containing sonogels show increased pore diameter, bigger pore volumes and diminished surface areas.

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Section: Ft-ir Analysismentioning

confidence: 93%

Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid

Putz

Len

Ianăși

et al. 2016

Korean J. Chem. Eng.

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“…The weak absorption band for S Si1 and The medium intense absorption band for S Si2 corresponding to the adsorbed water molecules deformation vibrations appear at 1615.27 and 1633.59 cm -1 , [22], respectively. The medium broad band at 1448.44 cm -1 revealed to symmetric and asymmetric bending of C-H bond of -CH 2 -CH 2 -and very intense broad band at 1161.07 cm -1 assigned to the longitudinal A) Water volume = 0 ml, B) 25 ml and C) 50 ml [25]. This difference in spectra between S Si1 and S Si2 may attributed to the impurities present in yellow sand such as Al and Ti.…”

Section: Ftirmentioning

confidence: 99%

Preparation and Characterization of Silica Nanoparticles by Wet Mechanical Attrition of White and Yellow Sand

Akl¹,

Aly²,

Soliman³

et al. 2013

J Nanomed Nanotechnol

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Mechanical alloying is a simple and useful processing technique that is now being employed in the production of nanocrystals and/or nanoparticles from all material classes. In the present work, preparation of silica nanoparticles (SiO 2 NPs) by wet mechanical attrition of white and yellow sand using a lab scaled ball mill was investigated. The different experimental parameters affecting the milling process were thoroughly studied such as the milling period, water volume and the initial size of sand particles. Analysis of the results obtained revealed that SiO 2 NPs with particle size 22-33 nm and 38-48 nm could successfully be prepared from original white and yellow sand, respectively. The optimum experimental parameters to obtain these SiO 2 NPs are 25 g original sand particle, 50 ml water, 113 g media weight and 8 hr milling period at 400 rpm mill speed. The SiO 2 NPs obtained were characterized by SEM, XRD, EDS and FTIR. The results obtained showed high homogeneity of the produced spherical SiO 2 NPs. These SiO 2 NPs have good potentials for use in industry such as their use as additive materials in ultrahigh performance concrete for the next development. Based on economic value, the produced SiO 2 NPs have excellent potential to be developed.SiO 2 NPs are used in many industries such as semiconductor technology, optical communication, removal of heavy metals and dyes from water, catalysts, pigments and pharmacy industry.SiO 2 NPs have been prepared by several techniques sol -gel process [6][7][8][9][10][11][12], microemulsion [13][14][15][16], oxidation of tetraethyl-orthosilicate TEOS in the bench-scale diffusion flame reactor [17], an interdigital micromixer and a batch reactor, have been used to prepare silica nanoparticles [18]. Recently, encapsulation of water insoluble drugs in mesoporous silica nanoparticles using supercritical carbon dioxide has been described [19].A literature survey revealed that little information is available regarding the preparation of SiO 2 NPs by wet mechanical attrition of white and yellow sand. The aim of the present study is to throw light on the preparation and characterization SiO 2 NPs by wet mechanical attrition white and yellow sand based on their following peculiar properties: 1) they have mechanic strength to enhance the usable life.2) The SiO 2 NPs possess nano-scaled size larger specific surface area allowing the easy adsorption of different environmental pollutants 3) the raw materials are low-cost and the synthetic approach is simple, which make these nanoparticles potentially commercializable. factors affecting the milling process were thoroughly investigated. The proposed method is particularly suitable for large quantity production, relatively simple with a few operation parameters, high homogenous product and low cost.

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“…The existence of terminal silanol groups (Si-OH) is responsible for the adsorption of water molecules on the material surface which deformation vibrations appear at 1,635 cm -1 [42]. Besides, the Si-O in-plane stretching vibrations of the silanol groups appear at 956 cm -1 [43]. The intense and broad band at 1,090-1,080 cm -1 and the shoulder at around 1,200 cm -1 are attributed to the transversal optical (TO) and longitudinal optical (LO) modes of the Si-O-Si asymmetric stretching vibrations of the dense silica network, where oxygen atoms play the role of bridges between each two silicon sites [44].…”

Section: Ftir Spectroscopymentioning

confidence: 99%

Synthesis and Characterization of Mesoporous Hybrid Silica-Polyacrylamide Aerogels and Xerogels

Ramadan

Coradin

Masse

et al. 2010

Silicon

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We report the synthesis of highly porous hybrid silica-polyacrylamide aerogels where the inorganic network was obtained through the hydrolysis and poly-condensation of tetramethoxysilane via a two-step sol-gel process while the polyacrylamide polymer was made by photocopolymerization of two organic monomers, the acrylamide and the bis-acrylamide. These aerogels were obtained after a carbon dioxide supercritical drying while the corresponding xerogels were dried by simple evaporation. These materials, as well as pure silica and polyacrylamide aerogels and xerogels, were characterized by FTIR spectroscopy, solid-state 29 Si and 13 C NMR spectroscopy, Thermogravimetric Analysis, a nitrogen adsorptiondesorption technique, and Scanning Electron Microscopy. The FTIR and NMR spectra and the TGA/DTA analyses confirm the coexistence of highly branched silica and polyacrylamide networks reflecting the hybrid nature of the materials obtained. Nitrogen adsorption measurements reveal high specific surface areas and pore size distributions disclosing the mesoporous character of these hybrid materials. Hybrid silica-polyacrylamide aerogels having a specific surface area equal to 572 m 2 /g and a pore volume 1.92 cm 3 /g were successfully prepared for the first time in this study. The high porosity of these aerogels is due to a better resistance of the silica network to capillary forces during the supercritical drying when silica coexists with a polyacrylamide network.

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EPR, optical, infrared and Raman spectral studies of Actinolite mineral

Cited by 72 publications

References 29 publications

Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid

Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid

Preparation and Characterization of Silica Nanoparticles by Wet Mechanical Attrition of White and Yellow Sand

Synthesis and Characterization of Mesoporous Hybrid Silica-Polyacrylamide Aerogels and Xerogels

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