基于低场核磁技术和环境扫描电镜的卷烟吸湿机制研究

Study on moisture adsorption mechanism by LF—NMR and ESEM

卷烟易吸湿,其水分含量对其品质有着较大的影响,为分析卷烟吸湿过程中水分变化规律及添加剂对其吸湿特性的影响,利用低场核磁技术(LF—NMR)测定不同卷烟样品弛豫时间分布,及其对应横向弛豫积分面积,采用环境扫描电镜(ESEM)分析不同湿度下卷烟样品表观特征及变化。结果表明,卷烟存在3个T2区间,其中T21反映的化学结合水是烟草水分主要存在形式;烟草自身吸湿以毛细管吸附为主,添加羟基等极性基团后吸湿机制转向化学吸附为主;海绵组织与栅栏组织是烟草内部重要的组织形态,其组织结构对卷烟吸湿有较大影响,其存在状态与组织结构受到水分含量与化学物质添加作用的共同影响。

Tobacco is hygroscopic products, and the moisture content has a significant impact on its quality. The relaxation time of differ ent cigarette samples were measured by low-field NMR techniques to study the moisture adsorption mechanism and the microstructure difference between different tobacco samples which in different water content and were observed by ESEM. T21 values are the most sensi- tive indicators reflected the bonding strength of water. The domina ted way of tobacco absorption is through the capillary sorption while after adding a polar group such as a hydroxyl the absorption mecha- nism steering chemisorptions. Spongy tissue and palisade tissue is an important organizational form of tobacco, its present state and organ- izational structure is subjected to the combined effect of moisture and chemicals adding.