木糖渣酶解耦合机械处理制备球形纳米纤维素

Preparation of Spherical Nanocellulose Using Enzymatic Hydrolysis and Mechanical Treatment from Corncob Residues

球形纳米纤维素(SNC)是一种环境友好型生物质材料,具有良好的生物降解性、生物相容性、高热稳定性、高强度等特点,可应用于生物医学、电子科技、环境治理、膜科学等领域.本文以木糖渣为原料,采用酶解耦合机械处理(超声破碎或高压均质)的方法,制备不同大小、形貌的SNC.考察了3种预处理方法、酶解时长、超声破碎时长、高压均质压力与循环次数对SNC形貌、粒径、结晶度和产率的影响及规律.结果表明:与氢氧化钠的醇溶液和水溶液相比,碱性过氧化氢处理使得木糖渣结晶度最高,由50.1%提高至74.7%;酶解3 h,超声破碎120 min所制得的SNC直径为30~80 nm,产率为50.6 mg/g;酶解3 h,80 MPa高压均质15次,所得SNC直径为10~40 nm,产率为80.6 mg/g.

Spherical nanocellulose(SNC)is an eco-friendly biomass material with good biodegradability,biocompatibility,high thermal stability,and high strength.It can be used in the fields of biomedical science,electronic technology,environmental remediation,membrane science,and so on.SNC with different sizes and morphologies can be obtained using enzymatic hydrolysis and mechanical treatment(sonication and high-pressure homogenization)of corncob residues.This paper investigated the effects of three pretreatment methods,enzymatic hydrolysis time,sonication time,high-pressure homogenization pressure and cycle times on the morphology,particle size,crystallinity,and yield of SNC.The results showed that the crystallinity of corncob residues was increased from 50.1%to 74.7% by alkaline hydrogen peroxide,which is higher than that obtained using sodium hydroxide and alcoholic sodium hydroxide.SNC with a diameter 30-80 nm and yield of 50.6mg/g was obtained through enzymatic hydrolysis for 3 h and sonication for 120 min.SNC with a diameter 10-40 nm and yield of 80.6mg/g after repeating enzymatic hydrolysis for 3 h and homogenization at 80 MPa for 15times.