Key Laboratory of Bio-based Materials Science and Technology of Ministry of Education, Northeast Forestry University, Harbin, PR China; Research Center of Wood Bionic Intelligent Science, Northeast Forestry University, Harbin, PR China.
Key Laboratory of Bio-based Materials Science and Technology of Ministry of Education, Northeast Forestry University, Harbin, PR China.
Int J Biol Macromol. 2019 Jul 15;133:243-252. doi: 10.1016/j.ijbiomac.2019.04.045. Epub 2019 Apr 8.
Bromothymol blue (BTB) was fixed on the cationic cellulose fibers (CCFs) to prepare pH sensitive fibers (pH-SFs). The pH-SFs as intelligent indicator were added into the semen cassiae gum (SCG) as a weakly acidic matrix to prepare a visual-olfactory film. The C NMR results show that the CCFs were successfully obtained by introducing hydroxypropyltriethylamine groups which showed strong affinity to BTB molecules. Rheology results demonstrated that all of the film-forming solutions were shear-thinned fluids with non-Newtonian behavior. Scanning electronic microscopy showed that the addition of pH-SFs makes the film surface rougher and rougher. The addition of pH-SFs < 3% improved the tensile strength of the film. The visual-olfactory film was sensitive to ammonia with a highly visible color change from pale yellow to blue-green. The SCG-3SFs film pre-treated in NaOH solution changed from blue to pale yellow while the raw milk was close to spoilage. The light yellow SCG-3SFs film changed to blue-green as the freshwater shrimp changed from fresh to spoilage. The results indicate that the visual-olfactory film can be used for perceiving the freshness of milk and freshwater shrimp.
溴百里酚蓝（BTB）固定在阳离子纤维素纤维（CCFs）上，制备 pH 敏感纤维（pH-SFs）。将 pH-SFs 作为智能指示剂添加到决明子胶（SCG）中作为弱酸性基质，制备可视-嗅觉薄膜。C NMR 结果表明，成功地通过引入羟丙基三乙胺基团制备了 CCFs，该基团对 BTB 分子表现出很强的亲和力。流变学结果表明，所有成膜溶液均为剪切变稀的非牛顿流体。扫描电子显微镜表明，添加 pH-SFs 会使薄膜表面变得越来越粗糙。添加 pH-SFs < 3%可提高薄膜的拉伸强度。可视-嗅觉薄膜对氨敏感，颜色从浅黄色变为蓝绿色，具有高度可见的颜色变化。用 NaOH 溶液预处理的 SCG-3SFs 薄膜由蓝色变为浅黄色，而原奶接近变质。浅黄色的 SCG-3SFs 薄膜随着淡水虾从新鲜变为变质而变为蓝绿色。结果表明，可视-嗅觉薄膜可用于感知牛奶和淡水虾的新鲜度。
