کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10603153 | 982464 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Degradation of chitosan and starch by 360-kHz ultrasound
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Degradation of chitosan and starch by 360-kHz ultrasound Degradation of chitosan and starch by 360-kHz ultrasound](/preview/png/10603153.png)
چکیده انگلیسی
Effects of 360-kHz ultrasound on aqueous solutions of chitosan and starch were studied. This treatment is an efficient procedure for reduction of molecular weight of both polysaccharides. It has been demonstrated that at the applied ultrasound frequency degradation is caused both by OH radicals and mechanochemical effects. In Ar-saturated 2Ã10â2 mol dmâ3 chitosan solutions, pH 3, at an ultrasound dose rate of 170 W kgâ1, the average sonochemical chain scission yield in the sonication time range of 0-90 min is ca. 8Ã10â11 mol Jâ1. This yield has been shown to depend on polymer concentration, ultrasound power and gas used to saturate the solution. Scission is accompanied by side reactions leading to the formation of carbonyl groups. Ultrasound-induced chain scission of starch proceeds with lower yield, one of the reasons being probably the different chain conformation when compared with rod-like chitosan macromolecules.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 60, Issue 2, 6 May 2005, Pages 175-184
Journal: Carbohydrate Polymers - Volume 60, Issue 2, 6 May 2005, Pages 175-184
نویسندگان
Renata Czechowska-Biskup, Bozena Rokita, Salah Lotfy, Piotr Ulanski, Janusz M. Rosiak,