微纳米木质素颗粒在酸碱溶液中的溶解行为

通过测试粒径,研究了具有微纳米尺寸的木质素颗粒在酸碱溶液中的溶解行为。结果显示:木质素在碱性溶液中的溶解无规律,但在酸性溶液中的溶解却首先是溶胀然后才是溶解,而这两者的分水岭似乎是在80min(25℃条件下),与酸液浓度无关。但值得关注的是这两者引起木质素颗粒的外型从球状改变为长方体。红外光谱显示木质素在酸性溶液中的溶解主要是其芳香环的断裂即分子量降低而无结构变化。

Dissolution Behavior for Micro/Nano Lignin Particles in Acid-Base Solutions

By taking particle diameter measurement as a tool,the behavior for lignin particles with micro-or nano size dissolved in acid or base solution has been studied.Results showed that lignin could not be dissolved in base under a room temperature,e.g.25℃,however,can be easily in acid solution.In addition to general understood,this paper showed that those mentioned lignin particles dissolved in acid solution,e.g.HCl,is initially swelled by acid then is expected dissolution.Moreover,it was found that the time,e.g.about 80 min,seems to be a watershed for understanding lignin in swelling or dissolution because these two phenomena were obviously observed to ignore the variety of acid concentration.However,SEM presented an of importance phenomenon indicated that lignin particles under swelling or dissolution might be greatly changed of its morphology due to a ball observed at about 60 min while a cuboid obviously at about 100 min.A comparison of FTIR spectra obtained at different acid reaction times furthermore indicated that lignin dissolved in acid solution caused changes only on the degradation without on its molecular structure.