摘要:
针对天然竹纤维粗细不均、变异性大的特点,采用Whihelmy 力学法测定了竹纤维的平均润湿周长及动态接 触角,利用Owens-Wendt 法对11 种浸润速率下的纤维表面能、色散及极性分量进行了表征,并借助边际均值研究了 测试速率与动态接触角、表面能的关系。结果表明:采用30 根纤维的平均润湿周长来估算动态接触角的方法是可 行的,其相对误差较小。随着测试速率的增加,动态前进接触角符合先快速增加后逐渐稳定的分子动力学模型,而 表面能有非线性减小的趋势。测试速率设置为1 ~3 mm/ min 较合理,此时测得竹纤维表面能为41.71 ~43.61 mN/ m。浸润速率在11 个水平下测定的动态接触角边际均值可分成7 组子集,高浸润速率下测得的纤维接触角比低浸 润速率的显著提高。动态接触角和测试速率的相关程度有14.11%由测试液体的协同作用产生。竹纤维表面能与 动态前进接触角边际均值呈负相关线性关系。
Abstract:
In regards to the characteristics of uneven thickness and a larger variability of natural plant fibers, average wetting perimeter and dynamic contact angle of bamboo fiber were determined by using Whihelmy technique. Surface energy, dispersion and polar components of fiber were characterized under 11 types of wetting speed by Owens-Wendt method. Also, the relationships between wetting speed and dynamic contact angle, wetting speed and surface energy were investigated with the help of marginal mean. The results showed that: the method of using average wetting perimeter of 30 fibers to estimate the circumference and dynamic contact angle was feasible, with a smaller relative error of 0.69%. As the testing rate increased, dynamic advancing contact angles imitated the molecular dynamics model, rapid rising at initial stage and then gradually level off, while surface energy showed a non鄄linear decreasing trend. Surface energy of bamboo fiber was calculated as 41.71 -43.61 mN / m when testing speed was set as 1 -3 mm/ min. Consistent subset analysis represented that marginal mean of dynamic contact angle at 11 levels can be divided into 7 groups, and each group can be considered as a subset. Dynamic contact angle was significantly increased under the high testing speed compared with the low one. Correlation and partial correlation analysis showed that 14.11% degree of correlation between dynamic contact angle and testing speed determined from synergies effect of testing liquid. It has a negative linear relation between the value of bamboo fiber'surface energy and marginal mean of dynamic advancing contact angle.
百度学术
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