College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, PR China.
College of Chemical Engineering, Sichuan University, Chengdu, 610065, PR China.
Carbohydr Polym. 2019 May 1;211:237-248. doi: 10.1016/j.carbpol.2019.01.084. Epub 2019 Jan 25.
Cellulose films are of poor water-vapor barrier performance. Herein, we put forward an effective way to suppress adsorption by crosslinking of hydroxyl groups via epichlorohydrin (ECH), meanwhile graphene oxide (GO) nanosheets are utilized to prolong the pathway of vapor penetration. The strategy confers a significant enhancement of vapor barrier performance as well as mechanical properties to cellulose-based films. Specifically, an outstanding reduction of 67.4% in water-vapor permeability coefficient is achieved in nanocomposite films compared to the uncrosslinked cellulose films. Furthermore, for the first time, two-dimensional correlation analysis reveals that crosslinking of ECH do not alter penetration direction, while GO can eminently act as shielding for the formation of bound water which change the sequential order of firstly-interacted vapor area from crystalline to amorphous area. Free volume is the penetration destination. The retarding effect introduced by the GO in amorphous area gives rise to the improvement of the vapor-barrier.
纤维素薄膜的水汽阻隔性能较差。在此，我们提出了一种通过环氧氯丙烷（ECH）交联羟基来抑制吸附的有效方法，同时利用氧化石墨烯（GO）纳米片来延长蒸汽渗透的途径。该策略赋予了纤维素基薄膜显著提高的水汽阻隔性能和机械性能。具体来说，与未交联的纤维素薄膜相比，纳米复合材料薄膜的水蒸气透过系数显著降低了 67.4%。此外，这是首次通过二维相关分析揭示了 ECH 的交联不会改变渗透方向，而 GO 可以作为阻挡层来阻止结合水的形成，从而改变了首先相互作用的蒸汽区域从结晶区到无定形区的顺序。自由体积是渗透的目的地。无定形区中 GO 引入的阻碍作用提高了阻隔性能。
