McDonagh Birgitte Hjelmeland, Chinga-Carrasco Gary
SINTEF Industry, P.O. Box 4760 Torgarden, 7034 Trondheim, Norway.
RISE PFI, Høgskoleringen 6b, 7491 Trondheim, Norway.
Polymers (Basel). 2020 Oct 30;12(11):2538. doi: 10.3390/polym12112538.
Bleached and unbleached pulp fibers were treated with 2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO) mediated oxidation to obtain cellulose nanofibrils (CNFs). The resulting bleached and unbleached CNFs were mixed with salicylic acid (0, 5, 10, 20 wt%) before casting and freeze-drying or 3D-printing. A series of methods were tested and implemented to characterize the CNF materials and the porous structures loaded with salicylic acid. The CNFs were characterized with atomic force microscopy and laser profilometry, and release of salicylic acid was quantified with UV-visible absorbance spectroscopy, conductivity measurements, and inductive coupled plasma mass spectrometry (ICP-MS). Fourier-transform infrared spectroscopy (FTIR) complemented the analyses. Herein, we show that aerogels of bleached CNFs yield a greater release of salicylic acid, compared to CNF obtained from unbleached pulp. The results suggest that biodegradable constructs of CNFs can be loaded with a plant hormone that is released slowly over time, which may find uses in small scale agricultural applications and for the private home market.
将漂白和未漂白的纸浆纤维用2,2,6,6-四甲基哌啶-1-氧基（TEMPO）介导的氧化处理，以获得纤维素纳米纤维（CNF）。在浇铸、冷冻干燥或3D打印之前，将所得的漂白和未漂白的CNF与水杨酸（0、5、10、20 wt%）混合。测试并实施了一系列方法来表征CNF材料和负载水杨酸的多孔结构。用原子力显微镜和激光轮廓仪对CNF进行表征，并用紫外可见吸收光谱、电导率测量和电感耦合等离子体质谱（ICP-MS）对水杨酸的释放进行定量。傅里叶变换红外光谱（FTIR）补充了分析。在此，我们表明，与从未漂白纸浆获得的CNF相比，漂白CNF的气凝胶能释放更多的水杨酸。结果表明，CNF的可生物降解构建体可以负载一种植物激素，该激素会随着时间的推移缓慢释放，这可能在小规模农业应用和私人家庭市场中找到用途。
