کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5357895 | 1388225 | 2010 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Water vapour sorption on hydrophilic and hydrophobic nanoporous materials
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
The aim of this study is to compare water vapour sorption isotherms on various mesoporous materials in their pristine state and after silanisation. Commonly the pristine state is regarded as hydrophilic and the silanised one as hydrophobic. Water vapour sorption experiments are discussed for a highly ordered nanoporous aluminium oxide with straight cylindrical channels of ca. 25Â nm diameter and for various controlled porous glasses (CPGs) with disordered pores in the range of 13Â nm diameter. The water sorption isotherms exhibit in both cases a hysteresis over the entire humidity range. At higher humidities the pristine materials show capillary condensation whereas for the silanised samples this phase transition does not occur or even a loss of water is recorded as for the silanised Al2O3. Surprisingly, for the silanised Al2O higher water uptake is observed in the low humidity region. Application of the excess surface work (ESW) method delivers a reduced structural component in the long range interaction of the water molecules with a hydrophobic surface. Inverse gas chromatography studies of the silanised CPGs result in an increased short range dispersive part of the surface energy with the increasing degree of silanisation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 256, Issue 17, 15 June 2010, Pages 5482-5485
Journal: Applied Surface Science - Volume 256, Issue 17, 15 June 2010, Pages 5482-5485
نویسندگان
Dirk Enke, Michael Rückriem, Andreas Schreiber, Jürgen Adolphs,