Novel Materials and Nanotechnology Group, IATA, CSIC, Apartado Correos 73, 46100 Burjassot, Spain.
J Agric Food Chem. 2010 Dec 22;58(24):12847-57. doi: 10.1021/jf102764e. Epub 2010 Nov 12.
The current study presents the development and characterization of novel carrageenan nanobiocomposites showing enhanced water barrier due to incorporation of cellulose nanowhiskers (CNW). CNW, prepared by acid hydrolysis of highly purified α cellulose microfibers, were seen to have a length of around 25-50 nm and a cross section of ca. 5 nm when dispersed in the matrix. The nanobiocomposites were prepared by incorporating 1, 3, and 5 wt % of the CNW into a carrageenan matrix using a solution casting method. Morphological data (TEM and optical microscopy) of the nanocomposites containing CNW were compared with the morphology of the corresponding biocomposites containing the original cellulose microfibers and the differences discussed. Thermal stability by TGA, water vapor permeability, and percent water uptake were also determined. The main conclusion arising from the analysis of the results is that the nanobiocomposites containing 3 wt % of CNW exhibited the lowest reduction in water vapor permeability, that is, ca. 71%, and that this reduction was largely attributed to a filler-induced water solubility reduction. This fully biobased nanoreinforced carrageenan can open new opportunities for the application of this biopolymer in food-packaging and -coating applications.
本研究开发并表征了新型卡拉胶纳米生物复合材料，由于掺入了纤维素纳米纤维（CNW），其水阻隔性能得到了增强。CNW 通过高度纯化的α纤维素微纤维的酸水解制备，当分散在基质中时，其长度约为 25-50nm，横截面约为 5nm。纳米生物复合材料通过溶液浇铸法将 1、3 和 5wt%的 CNW 掺入卡拉胶基质中制备而成。对含有 CNW 的纳米复合材料的形态数据（TEM 和光学显微镜）与含有原始纤维素微纤维的相应生物复合材料的形态进行了比较，并对差异进行了讨论。还测定了热稳定性（TGA）、水蒸气透过率和吸水率。对结果进行分析得出的主要结论是，含有 3wt%CNW 的纳米生物复合材料表现出最低的水蒸气透过率降低，约为 71%，这种降低主要归因于填充剂引起的水溶性降低。这种完全基于生物的纳米增强卡拉胶为该生物聚合物在食品包装和涂层应用中的应用开辟了新的机会。
