Institute of Biomedical and Pharmaceutical Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350002, China.
Institute of Biomedical and Pharmaceutical Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350002, China.
Carbohydr Polym. 2020 May 15;236:115999. doi: 10.1016/j.carbpol.2020.115999. Epub 2020 Feb 16.
Cellulose nanofibers (CNFs) from kelp were prepared by cellulase treatment with lengths greater than 3 μm. CNFs were further oxidized by TEMPO-oxidized system, and the lengths of the oxidized CNFs (TEMPO-CNFs) were 0.6-1 μm. AFM and TEM images showed that intertwined CNFs fibers were divided into individual nanofibrils. The crystallinity of TEMPO-CNFs increased to 66.5 %. TGA analysis indicated that TEMPO-CNFs were more sensitive to temperature than cellulose and CNFs. FT-IR spectra revealed no changes in the basic cellulose structures of CNFs and TEMPO-CNFs. In the sunflower oil/water (20/80, v/v) model emulsions, the oil droplet sizes were less than 20 μm in CNFs emulsions, which became smaller in TEMPO-CNFs emulsions. Delamination was found in CNFs emulsions after three days of storage. Addition of NaCl increased the volumes of TEMPO-CNFs emulsions but enlarged the oil droplets sizes. TEMPO-CNFs emulsions had the largest volume with smallest and most homogeneous oil droplets at pH 3. TEMPO-CNFs emulsions showed good stability after storage for 30 days. Further, TEMPO-CNFs could also emulsify 50 % (v/v) of sunflower oil. All these results indicated that TEMPO-CNFs can be used in preparing Pickering emulsions.
从海带中用纤维素酶处理制备长度大于 3 μm 的纤维素纳米纤维（CNFs）。进一步用 TEMPO 氧化体系氧化 CNFs，氧化 CNFs（TEMPO-CNFs）的长度为 0.6-1 μm。原子力显微镜和透射电子显微镜图像表明，交织的 CNF 纤维被分成单个纳米原纤维。TEMPO-CNFs 的结晶度增加到 66.5%。TGA 分析表明，TEMPO-CNFs 比纤维素和 CNFs 对温度更敏感。FT-IR 谱表明 CNFs 和 TEMPO-CNFs 的纤维素结构基本没有变化。在葵花籽油/水（20/80，v/v）模型乳液中，CNFs 乳液中的油滴尺寸小于 20 μm，而在 TEMPO-CNFs 乳液中则更小。在储存三天后，CNFs 乳液发生分层。添加 NaCl 会增加 TEMPO-CNFs 乳液的体积，但会增大油滴的尺寸。在 pH 3 时，TEMPO-CNFs 乳液具有最大的体积，油滴最小且最均匀。TEMPO-CNFs 乳液在储存 30 天后仍具有良好的稳定性。此外，TEMPO-CNFs 还可以乳化 50%（v/v）的葵花籽油。所有这些结果表明，TEMPO-CNFs 可用于制备 Pickering 乳液。
