کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1387062 982545 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modification of surface properties of thin polysaccharide films by low-energy electron exposure
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Modification of surface properties of thin polysaccharide films by low-energy electron exposure
چکیده انگلیسی

The effect of low-energy electron irradiation on thin layers of two different polysaccharide materials, namely amylose and chitosan, has been investigated. Modification of the samples occurs at electron energies as low as 5 eV. In the case of amylose, a change in the wetting properties is observed upon exposure. Loss of oxygen from the hydroxyl groups and consequent formation of a hydrocarbon material is responsible for this effect as revealed by analysing the samples before and after electron exposure by means of reflection absorption infrared spectroscopy (RAIRS) and X-ray photoelectron spectroscopy (XPS). It is shown that the amide side groups in chitosan are more reactive than the hydroxyl groups and consequently dominate the modifications in this case. Additional experiments by high-resolution electron energy loss spectroscopy (HREELS) on thin condensed films of the model compound α-d-glucose show that facile oxidation of the saccharide occurs in the presence of O2. Traces of O2 as a residual gas can therefore be held responsible for the formation of carboxyl groups that are observed by RAIRS in samples of amylose after electron exposure.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 83, Issue 2, 10 January 2011, Pages 608–615
نویسندگان
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