Department of Food Science and Technology, Faculty of Agriculture and Natural resources, University of Mohaghegh Ardabili, Ardabil, P.O. Box: 56199-11367, Iran.
Department of Food Science and Technology, Faculty of Agriculture and Natural resources, University of Mohaghegh Ardabili, Ardabil, P.O. Box: 56199-11367, Iran.
Carbohydr Polym. 2018 Nov 1;199:415-425. doi: 10.1016/j.carbpol.2018.07.031. Epub 2018 Jul 10.
In this study, a novel carboxymethyl cellulose (CMC)-based ternary nanocomposite films containing sodium montmorillonite (Na-MMT) (1, 3 and 5% wt) and titanium dioxide (TiO) (1, 3 and 5% wt) nanoparticles (NPs) were made via casting method. The results showed that addition of NPs decremented water vapor permeability of the films up to 39% and 50% by adding Na-MMT, and Na-MMT + TiO, respectively, while moisture content, density and glass transition temperature incremented slightly. The nanoclays amplified resistance of the nanocomposites against tensile stress and Young's modulus (YM) of the films at the expense of elongation at break. A synergistic effect of NPs on moisture uptake reduction (≈ 40%) of films was observed. Nano-TiO was strongly effective in UV-light blocking (The films containing 5% TiO removed more than 99% of UV and more than 98% of visible lights). The interactions, crystallinity and morphology of the nanocomposites were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). Development of hydrogen bonds between the hydroxyl groups of CMC and nanoparticles was indicated by FT-IR spectroscopy. Conforming to the XRD analysis, clay nanolayers organized an intercalated structure in the nanocomposites, whereas a limited agglomeration of TiO nanoparticles led to increment of films crystallinity. SEM micrographs showed well-dispersed Na-MMT and TiO NPs through the films surface especially at low concentrations. In conclusion, although the films loaded with nanoclays exhibited better properties than the control film, inclusion of TiO more improved the functional characteristics of them and extended the potential as a biodegradable packaging.
在这项研究中，通过浇注法制备了一种新型的羧甲基纤维素（CMC）基三元纳米复合薄膜，其中含有钠蒙脱石（Na-MMT）（1、3 和 5wt%）和纳米二氧化钛（TiO）（1、3 和 5wt%）纳米粒子（NPs）。结果表明，添加 NPs 可使薄膜的水蒸气透过率降低 39%和 50%，分别添加 Na-MMT 和 Na-MMT+TiO，而水分含量、密度和玻璃化转变温度略有增加。纳米粘土放大了纳米复合材料对拉伸应力的阻力和薄膜的杨氏模量（YM），但其断裂伸长率降低。观察到 NPs 对薄膜吸湿性降低（≈40%）的协同效应。纳米 TiO 对阻挡紫外线（含有 5%TiO 的薄膜可去除超过 99%的紫外线和超过 98%的可见光）具有很强的作用。通过傅里叶变换红外（FT-IR）光谱、X 射线衍射（XRD）分析和扫描电子显微镜（SEM）研究了纳米复合材料的相互作用、结晶度和形态。FT-IR 光谱表明，纳米复合材料中 CMC 的羟基与纳米粒子之间形成了氢键。XRD 分析表明，粘土纳米层在纳米复合材料中形成了插层结构，而 TiO 纳米粒子的有限聚集导致了薄膜结晶度的增加。SEM 显微照片显示，纳米 Na-MMT 和 TiO 均匀分散在薄膜表面，特别是在低浓度时。总之，尽管负载纳米粘土的薄膜表现出比对照薄膜更好的性能，但 TiO 的加入更能改善它们的功能特性，并扩大了作为可生物降解包装的潜力。
