氧化石墨烯表面改性聚乳酸薄膜的制备与性能研究
发布时间：2018-12-07 21:22
【摘要】：为了减少石油基塑料材料的使用，保护环境，缓解当下日益严峻的石油资源短缺的问题，开发和利用生物基可降解的环保型塑料材料成了包装材料领域的研究重点。聚乳酸(Poly(lactic acid), PLA)材料是目前应用最为广泛的可降解塑料材料之一，作为包装薄膜材料，PLA具有很好的透明度、机械性能和生物相容性，但PLA薄膜的阻隔性能较差，大大地限制了它在包装领域的应用。氧化石墨烯(Graphene Oxide, GO)，是石墨烯的一种重要的衍生物，具有和石墨烯相似的二维片层结构，不仅有很好的机械性能和生物相容性，更是很好的阻隔性材料，并且它的制备简单、安全，有广泛的应用前景。 本文采用层层自组装法(Layer-by-layer assembly, LBL)，利用氧化石墨烯(GO)和聚电解质阳离子聚乙烯亚胺(Polyethyleneimine, PEI)之间的静电结合力，将氧化石墨烯/聚乙烯亚胺的多层膜(GO/PEI)n沉积到PLA基膜的表面以提高PLA薄膜的阻隔性能。实验结果发现：多层膜(GO/PEI)n对PLA薄膜透氧性能的降低有极好的作用，当GO的浓度为0.5mg/ml，多层膜的组装层数n≥4时，PLA薄膜的透氧量下降了99%以上；经GO层层自组装后的PLA薄膜还有较好的透光性能和力学性能；但对薄膜透湿性能的降低作用不够理想，透湿量仅比原PLA基膜下降了15.12%。为了更好的降低此层层自组装复合PLA薄膜的透湿性能，采用十六烷基三甲基溴化铵(CTAB)对氧化石墨烯进行改性，提高氧化石墨烯材料的疏水性，得到的改性氧化石墨烯(m-GO)再和PEI层层自组装到PLA基膜材料的表面，接触角测试表明：m-GO有效地提高了多层膜对水的接触角，，在相同浓度条件下(m-GO/PEI)16PLA薄膜的接触角比(GO/PEI)16PLA薄膜提高了40.20o；与原PLA基膜相比(m-GO/PEI)16PLA薄膜的透湿量也下降了40.73%，相比(GO/PEI)nPLA薄膜，透湿性能有了明显的下降。 在此基础上，为了能进一步降低此类层层自组装复合PLA薄膜的透湿性能，又用溶胶-凝胶法(Sol-Gel)在GO和m-GO层层自组装复合PLA薄膜表面沉积了SiOx层，(此类层层自组装复合PLA薄膜也称为多层复合薄膜)。SiOx在多层复合薄膜的表面沉积的过程中，填补了多层膜(GO/PEI)n和(m-GO/PEI)n的表面以及它们层层之间的空隙。通过AFM和表面接触角图像的观察可知：沉积SiOx后，(GO/PEI)nPLA薄膜的表面粗超度和对水的接触角都增大了；相反，(m-GO/PEI)nPLA薄膜的则都是被减小了。增加SiOx层后有效阻隔了GO亲水层对水分子的吸附，以此减少了(GO/PEI)nPLA薄膜的透湿量，当n=16时，透湿量下降了41.63%；而(m-GO/PEI)n层本身有较好的疏水性，在沉积SiOx后(m-GO/PEI)nPLA薄膜的透湿性能没有明显的变化。
[Abstract]:In order to reduce the use of petroleum-based plastics, protect the environment and alleviate the increasingly severe shortage of petroleum resources, the development and utilization of biodegradable environment-friendly plastic materials has become the focus of research in the field of packaging materials. Polylactic acid (Poly (lactic acid), PLA) is one of the most widely used degradable plastic materials. As a packaging film material, PLA has good transparency, mechanical properties and biocompatibility, but the barrier property of PLA film is poor. It greatly limits its application in the field of packaging. Graphene oxide (Graphene Oxide, GO),) is an important derivative of graphene. It has a two-dimensional lamellar structure similar to graphene. It not only has good mechanical properties and biocompatibility, but also has a good barrier material. Moreover, its preparation is simple, safe and has wide application prospect. In this paper, the layer by layer self-assembly (Layer-by-layer assembly, LBL),) method was used to utilize the electrostatic binding force between graphene oxide (GO) and polyelectrolyte cationic polyimide (Polyethyleneimine, PEI). The multilayer (GO/PEI) n of graphene oxide / polyethyleneimine was deposited on the surface of PLA substrate to improve the barrier property of PLA film. The experimental results show that multilayer (GO/PEI) n has an excellent effect on the oxygen permeability of PLA films. When the concentration of GO is 0.5 mg / ml and the number of assembled layers n 鈮
本文编号：2367894
[Abstract]:In order to reduce the use of petroleum-based plastics, protect the environment and alleviate the increasingly severe shortage of petroleum resources, the development and utilization of biodegradable environment-friendly plastic materials has become the focus of research in the field of packaging materials. Polylactic acid (Poly (lactic acid), PLA) is one of the most widely used degradable plastic materials. As a packaging film material, PLA has good transparency, mechanical properties and biocompatibility, but the barrier property of PLA film is poor. It greatly limits its application in the field of packaging. Graphene oxide (Graphene Oxide, GO),) is an important derivative of graphene. It has a two-dimensional lamellar structure similar to graphene. It not only has good mechanical properties and biocompatibility, but also has a good barrier material. Moreover, its preparation is simple, safe and has wide application prospect. In this paper, the layer by layer self-assembly (Layer-by-layer assembly, LBL),) method was used to utilize the electrostatic binding force between graphene oxide (GO) and polyelectrolyte cationic polyimide (Polyethyleneimine, PEI). The multilayer (GO/PEI) n of graphene oxide / polyethyleneimine was deposited on the surface of PLA substrate to improve the barrier property of PLA film. The experimental results show that multilayer (GO/PEI) n has an excellent effect on the oxygen permeability of PLA films. When the concentration of GO is 0.5 mg / ml and the number of assembled layers n 鈮
本文编号：2367894
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