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首页> 外文期刊>Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites >Study of the influence of some DCCAs on the structure of sol-gel silica membranes
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Study of the influence of some DCCAs on the structure of sol-gel silica membranes

机译：一些DCCA对溶胶-凝胶二氧化硅膜结构的影响研究

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We obtained silica gel membranes by sol-gel processing. In order to study the effect of some drying control chemical additives, we used an alkoxide/additive molar ratio of 1/1. The performance of the drying additives in obtaining crack-free gels was evaluated through monolithicity measurements. The structural evolution occurring in the interconnected network of the membranes during thermal treatment was monitored by Fourier transform infrared spectroscopy, structural density measurements and nitrogen gas sorption. The degree of cross-linking of the silica network was inferred from the frequency of the Si-O(Si) vibration in the range. We noted that in the presence of formamide and N,N-dimethylformamide, the Si-O-Si bonds are stronger and belong to a more cross-linked structure. Changes in the chemical properties of the membranes, evaluated by quantities of molecular water and silanol groups on their surface, were monitored by absorption bands in the range of 3800-3000 cm(-1). Membranes obtained with additives have surfaces covered by a large content of isolated silanol groups even when annealed at 800 degreesC. The membrane obtained in the presence of amide has larger pore volume and its pore structure is in the range of mesoporosity. The membranes without additive and with propylene carbonate are microporous. Formamide and N,N-dimethylformamide allowed the preparation of crack-free membranes stabilized at high temperatures. (C) 2003 Elsevier B.V. All rights reserved. [References: 22]
机译：我们通过溶胶-凝胶法获得了硅胶膜。为了研究某些干燥控制化学添加剂的效果，我们使用1/1的醇盐/添加剂摩尔比。通过整体性测量来评估干燥添加剂在获得无裂纹凝胶中的性能。通过傅立叶变换红外光谱，结构密度测量和氮气吸附监测在热处理过程中在膜的互连网络中发生的结构演变。从该范围内的Si-O（Si）振动的频率推断出二氧化硅网络的交联度。我们注意到在存在甲酰胺和N，N-二甲基甲酰胺的情况下，Si-O-Si键更牢固，并且属于更交联的结构。膜的化学性质的变化，通过其表面的分子水和硅烷醇基团的数量进行评估，并通过3800-3000 cm（-1）范围内的吸收带进行监测。用添加剂获得的膜即使在800℃退火时，其表面也被大量孤立的硅烷醇基团覆盖。在酰胺存在下获得的膜具有较大的孔体积，并且其孔结构在介孔率范围内。没有添加剂并且带有碳酸亚丙酯的膜是微孔的。甲酰胺和N，N-二甲基甲酰胺可以制备在高温下稳定的无裂纹膜。 （C）2003 Elsevier B.V.保留所有权利。 [参考：22]

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