MFC气凝胶的制备及其精油缓释性能研究

Preparation and Essential Oil’s Sustained-release Property of MFC Aerogel

目的利用孔隙率高、比表面积大和吸附性能好的微纤化纤维素(MFC)气凝胶与百里香精油结合,解决抗菌保鲜包装中精油释放过快的问题,实现精油的缓慢释放。方法采用不同用量的内切纤维素酶预处理桉木漂白硫酸盐浆,通过高压均质制备MFC,经冷冻干燥制备MFC气凝胶,在基本性能表征的基础上,研究其精油缓释性能。结果由百里香精油的GC-MS分析得出其主要抑菌成分为麝香草酚。MFC气凝胶均为三维多孔结构,比表面积和平均孔径的变化范围分别为2.0~5.1m^2/g和5.0~22.0nm;当精油与MFC的质量比为1∶1时,MFC气凝胶的精油初始保留率为4.38mg/g(每克气凝胶中保留4.38mg精油),向密闭容器释放的精油量均呈现出先增大后减小,随后逐渐稳定的趋势,释放速率平均为3.1%。结论MFC气凝胶为高孔隙率、中孔材料,可延长精油释放时间,具有优异的缓释性能。

The work aims to solve the excessive release problem of essential oil in antibacterial fresh-keeping packaging and achieve its sustained release by means of the microfibrillated cellulose (MFC) aerogel which has high porosity,large specific surface area and good adsorption performance combined with thyme essential oil.The pretreatedment of eucalyptus bleached kraft pulp was carried out with different dosages of endocellulase and high pressure homogenization was used to prepare MFC.MFC aerogel was prepared by freeze drying,and the sustained release properties of its essential oil were studied based on the basic performance characterization.GC-MS analysis of thyme essential oil showed that,the main antibacterial component of it was thymol.MFC aerogels were of a three-dimensional porous structure.The specific surface area of aerogel varied from 2.0 to 5.1 m^2/g,and the average pore size ranged from 5.0 to 22.0 nm.When the essential oil: MFC mass ratio was 1∶1,the initial retention rate of essential oil of MFC aerogel was 4.38 mg/g (4.38 mg essential oil remained in per gram of aerogel),and the amount of essential oil released to the sealed container showed a trend of increasing first,then decreasing and gradually stabilizing with the average release rate of 3.1%.MFC aerogel is a kind of mesoporous material of high porosity that can prolong the release time of essential oil and has excellent sustained release properties.