Effect of ammonium salts on dispersive and adsorptive parameters of silicas precipitated from sodium metasilicate solution

Żurawska, Jolanta; Krysztafkiewicz, Andrzej; Jesionowski, Teofil

doi:10.1016/s0927-7757(03)00192-4

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…These properties limit the application of amorphous silica in organic materials. Modifiers are used to modify the surface of amorphous silica to be hydrophobic-lipophilic and to improve the compatibility between amorphous silica particles and polymer molecules, the interaction between the filler and polymer, the processing technology, and the performance of reinforcing filler [10][11][12][13][14][15][16]. In order to investigate the methods of preparing amorphous silica from oil shale residue and modifying its surface, in this paper an alkaline dissolution -homogeneous chemical sedimentation method is applied.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Amorphous Silica From Oil Shale Residue and Surface Modification by Silane Coupling Agent

Xu¹,

Ji²,

De-Min³

et al. 2010

Oil Shale

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Two kinds of modified amorphous silica, grafted vinyl trimethoxysilane and N-(n-butyl)-3-aminopropyl trimethoxysilane (DYNASYLAN 1189), were obtained from oil shale residue by the technical process of calcination and activation, alkaline dissolution, homogeneous sedimentation with ethylacetate and modification with silane coupling agents. The number of surface hydroxyl groups, modification degree, the structure and other properties of amorphous silica were investigated by chemical method, infrared analysis, nuclear magnetic resonance analysis, X-ray diffraction and scanning electron microscopy. The results show that amorphous silica treated with coupling agents AH-171 and DYNASYLAN 1189 is characterized by modification degrees of surface hydroxyl groups 93.7% and 71.2% and hydrophobic degrees 98% and 94%, respectively, as well as also by improved dispersion in organic solutions. This work gives a valid method to prepare surface modified amorphous silica from the oil shale residue.

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Section: Introductionmentioning

confidence: 99%

Preparation of Amorphous Silica From Oil Shale Residue and Surface Modification by Silane Coupling Agent

Xu¹,

Ji²,

De-Min³

et al. 2010

Oil Shale

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“…Silica may be used as thickening agent of rubber and strengthening agent of coating products. The residue is neither able to react, nor compatible with organics, difficult to infiltrate and disperse because of hydroxyls on its surface, so hydroxyls must be alkylated to get hydrophobic modified silica [14][15][16][17][18][19][20][21]. Modified silica can be obtained from the oil shale residue by treating it with silane coupling agents vinyltrimethoxysilane (AH-171) and N-(normal-butyl)-3-aminopropyl trimethoxysilane (DYNASYLAN 1189) as modifiers, and adopting the process route of calcination and activation → alkaline dissolution → homogeneous sedimentation with ethyl acetate → modification with silane coupling agents, at what the modification rate of hydroxyls on the surface are 93.7% and 71.2% [21], respectively.…”

Section: Introductionmentioning

confidence: 99%

Technique of Preparing Modified Silica From Oil Shale Residue

Xu¹,

Ji²,

Jia-Wei³

et al. 2011

Oil Shale

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The raw material -residue of oil production from Huadian oil shale -was modified with cationic surfactants; the hydroxyl groups on the aggregated silica surface were alkylated directly. The structure of alkylated Si-hydroxyl on modified silica surface was characterized by means of infrared spectroscopy, nuclear magnetic resonance analysis, thermal gravimetric analysis and scanning electron microscopy analysis. The results showed that modification rate of hydroxyl groups on the surface of the modified silica obtained was about 84%. The modification conditions were optimized basing on application of the orthogonal experimental method, and the optimum parameters were as follows: the reaction temperature of water medium -40 °C, pH value within the range of 9-10, and the molar ratio of cationic surfactant to silica hydroxyl on the surface -2:1.

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“…In modern new methods, non-metallic minerals and their derived are used as raw materials as silica source for hydrated silica by precipitation method. The critical methods include the silica crystal and silicate are transformed into non-crystal silica [1][2][3][4][5][6]. Their raw materials are mainly wollastonite, olivine, snake-tripe stone, kaolin, coal gangue, fly ash and so on [7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Process Investigation for Purifying Hydrated Silica from Fly Ash by Acid and Alkali Combination Method

Liu

Guo

2010

AMR

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In this paper, with sodium carbonate as an auxiliary agent in the fly ash, the mixtures were sintered at 880°C for 90 min, then dissolved by different concentrations of sulfuric acid respectively for extracting the hydrated silica. The results show that when the activated ash fly is dissolved by different concentrations of sulfuric acid, the dissolution rates of ash fly increase with the concentration of sulfuric acid increasing. Impurities of aluminum and iron atoms are present in an orderly array of micro-andalusite structure in the generative hydrated silica. When they are dissolved by sulfuric acid for 2%(wt%), the orderly structure is destroyed obviously, and the aluminum and iron atoms are separated out. The purity of hydrated silica can reach 99.9%.

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Effect of ammonium salts on dispersive and adsorptive parameters of silicas precipitated from sodium metasilicate solution

Cited by 8 publications

References 13 publications

Preparation of Amorphous Silica From Oil Shale Residue and Surface Modification by Silane Coupling Agent

Preparation of Amorphous Silica From Oil Shale Residue and Surface Modification by Silane Coupling Agent

Technique of Preparing Modified Silica From Oil Shale Residue

Process Investigation for Purifying Hydrated Silica from Fly Ash by Acid and Alkali Combination Method

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