کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
612595 880702 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecularly smooth cellulose surfaces for adhesion studies
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Molecularly smooth cellulose surfaces for adhesion studies
چکیده انگلیسی

Cellulose is deposited on silicon wafer surfaces via spin coating from a solution of cellulose in dimethylacetamide (+7%+7% lithium chloride). The resulting cellulose layers were analyzed by ellipsometry, AFM, FTIR, ICP-MS, X-ray reflectivity, and contact angle measurements. For cellulose concentrations below 0.07 wt% the wafer surfaces are covered with a network of cellulose fibrils. For concentrations between 0.07 and 0.5 wt%, closed films with thicknesses between 1.5 and ≈10 nm are obtained. These films are molecularly smooth (rms roughness < 2 nm). Higher concentrations result in thicker films with significantly rougher surfaces (rms roughness > 2 nm). The cellulose layers were used to investigate cellulose/cellulose adhesion and their modification by polyelectrolytes. To this end the sticking behavior of cellulose beads was analyzed. It is demonstrated that the sticking of the beads depends on the type, amount, and adsorption symmetry of adsorbed polyelectrolyte. Low, incomplete polyelectrolyte coverage always enhances sticking, whereas for high coverage the symmetry of the polyelectrolyte coating is very important. In this case, sticking (adhesion) is enhanced if only one surface is covered with polyelectrolyte prior to contact. If both surfaces were fully covered with polyelectrolytes before contact, sticking (adhesion) is decreased.

3D-view and thickness profile of a region with and without cellulose film (scratched off with the tips of tweezers). The thickness profile is taken from an averaged box of 2×3 μm2×3 μm along the edge.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 301, Issue 2, 15 September 2006, Pages 376–385
نویسندگان
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