农作物秸秆表面特性研究

Study on the surface characteristics of crop straw

研究了菜籽杆、莜麦杆、小麦秆和向日葵秸秆的显微构造,对4种农作物秸秆表面采用热碱、水热、稀酸、微波、高温蒸汽等多种方法进行处理,并进行了接触角的测定。实验结果表明,以上处理方法均能减少秸秆表皮木质素的含量,使其表面粗糙度提高,固液界面张力下降,接触面积增加;经热氢氧化钠、水热、稀硫酸、乙酸、微波、高温蒸汽处理后,菜籽秸秆接触角分别平均降低了36.3046°、22.9034°、22.2952°、15.3827°、19.0167°、16.5680°;莜麦秸秆接触角分别平均降低了20.4242°、5.0017°、2.9163°、3.3952°、12.3357°、5.9703°;小麦秸秆接触角分别平均降低了25.3517°、4.0027°、2.3433°、12.5973°、8.8697°、6.4633°;向日葵秸秆接触角分别平均降低了27.1917°、3.8204°、4.4057°、6.4994°、3.7410°、3.7169°。热碱处理后秸秆的润湿性明显增强,高温处理秸秆的润湿性改善较差;小麦秸秆润湿性最佳,菜籽秸秆的润湿性最差。

The microstructure of rapeseed straw,naked oats straw,wheat straw and sunflower straw were studied.4 crop straws were treated using a variety of processing methods such as hot sodium hydroxide treatment,hydrothermal treatment,diluted acid treatment,microwave treatment and steam treatment.Contact Angles were measured by contact angle tester.The results showed that all the methods could reduce the content of lignin,increased the surface roughness,reduced the solid-liquid interfacial tension,increased the contact area.The contact angle test of rapeseed straw revealed that after treatments with hot sodium hydroxide,hydrothermal,sulfuric acid,acetic acid,microwave and steam,the contact angle decreased by 36.3046°,22.9034°,22.2952°,15.3827°,19.0167°,16.5680°on average,respectively.The contact angle test of naked oats straw decreased by 20.4242°,5.0017°,2.9163°,3.3952°,12.3357°,5.9703°on average,respectively.The contact angle test of wheat straw decreased by 25.3517°,4.0027°,2.3433°,12.5973°,8.8697°,6.4633°on average,respectively.The contact angle test of sunflower straw decreased by 27.1917°,3.8204°,4.4057°,6.4994°,3.7410°,3.7169°on average,respectively.The wettability of crop straws were obviously enhanced after treatment of hot sodium hydroxide,the wettability of straws were poor by steam treatment.The wettability of wheat straw was the best,while rapeseed straw was the worst.