麦秆表面自由能及其分量研究

Study on Wheat Straw Surface Free Energy and Its Polar and Non Polar Part

连续跟踪不同处理麦秆表面接触角随时间的变化值,确定用于计算表面自由能的接触角数据,依据Young方程及Owens-Wendt-Kaelble法,求解不同处理麦秆表面自由能及其极性和非极性分量(色散力分量)。结果表明,未经处理麦秆外表面自由能为37.20 mJ/m2,其非极性分量占84.11%,内表面自由能高达51.54 mJ/m2,其非极性分量占50.50%。经1%的NaOH溶液95℃和85℃热处理,麦秆外表面自由能由37.20 mJ/m2增至51.72 mJ/m2和44.21 mJ/m2,其极性分量增加了377.58%和229.13%。经180℃和160℃热处理,麦秆外表面自由能变化不显著,但其极性分量显著增加,非极性分量显著降低。

The contact angles for calculating free energy of wheat straw surface pretreated with different methods were chosen by continuous monitoring the response of contact angles to time. The surface free energies and its polar and non polar part were studied, based on Young equation and methods suggested by Owens-Wendt-Kaelble. The results reveal that both free energy of out and inner surfaces untreated are 37.20 mJ/m^2and 51.54 mJ/m^2, wherein the non polar part of out and inner surfaces accounts for 84.11% and 50.50%, respectively. After pretreated with 1% NaOH solution at 95℃ and 85℃, 51.72 mJ/m^2and 44.21 mJ/m^2out surface free energy are achieved,wherein the polar part increases 377. 58% and 229.13%, respectively. Pretreated at 180℃ and 160℃, the out surface free energy changes a little, but its polar part elevats significantly, its non polar Dart decreases sienificantlv.