【摘要】：為了減少石油基塑料材料的使用，保護(hù)環(huán)境，緩解當(dāng)下日益嚴(yán)峻的石油資源短缺的問(wèn)題，開(kāi)發(fā)和利用生物基可降解的環(huán)保型塑料材料成了包裝材料領(lǐng)域的研究重點(diǎn)。聚乳酸(Poly(lactic acid), PLA)材料是目前應(yīng)用最為廣泛的可降解塑料材料之一，作為包裝薄膜材料，PLA具有很好的透明度、機(jī)械性能和生物相容性，但PLA薄膜的阻隔性能較差，大大地限制了它在包裝領(lǐng)域的應(yīng)用。氧化石墨烯(Graphene Oxide, GO)，是石墨烯的一種重要的衍生物，具有和石墨烯相似的二維片層結(jié)構(gòu)，不僅有很好的機(jī)械性能和生物相容性，更是很好的阻隔性材料，并且它的制備簡(jiǎn)單、安全，有廣泛的應(yīng)用前景。 本文采用層層自組裝法(Layer-by-layer assembly, LBL)，利用氧化石墨烯(GO)和聚電解質(zhì)陽(yáng)離子聚乙烯亞胺(Polyethyleneimine, PEI)之間的靜電結(jié)合力，將氧化石墨烯/聚乙烯亞胺的多層膜(GO/PEI)n沉積到PLA基膜的表面以提高PLA薄膜的阻隔性能。實(shí)驗(yàn)結(jié)果發(fā)現(xiàn)：多層膜(GO/PEI)n對(duì)PLA薄膜透氧性能的降低有極好的作用，當(dāng)GO的濃度為0.5mg/ml，多層膜的組裝層數(shù)n≥4時(shí)，PLA薄膜的透氧量下降了99%以上；經(jīng)GO層層自組裝后的PLA薄膜還有較好的透光性能和力學(xué)性能；但對(duì)薄膜透濕性能的降低作用不夠理想，透濕量?jī)H比原PLA基膜下降了15.12%。為了更好的降低此層層自組裝復(fù)合PLA薄膜的透濕性能，采用十六烷基三甲基溴化銨(CTAB)對(duì)氧化石墨烯進(jìn)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層層自組裝到PLA基膜材料的表面，接觸角測(cè)試表明：m-GO有效地提高了多層膜對(duì)水的接觸角，，在相同濃度條件下(m-GO/PEI)16PLA薄膜的接觸角比(GO/PEI)16PLA薄膜提高了40.20o；與原PLA基膜相比(m-GO/PEI)16PLA薄膜的透濕量也下降了40.73%，相比(GO/PEI)nPLA薄膜，透濕性能有了明顯的下降。 在此基礎(chǔ)上，為了能進(jìn)一步降低此類層層自組裝復(fù)合PLA薄膜的透濕性能，又用溶膠-凝膠法(Sol-Gel)在GO和m-GO層層自組裝復(fù)合PLA薄膜表面沉積了SiOx層，(此類層層自組裝復(fù)合PLA薄膜也稱為多層復(fù)合薄膜)。SiOx在多層復(fù)合薄膜的表面沉積的過(guò)程中，填補(bǔ)了多層膜(GO/PEI)n和(m-GO/PEI)n的表面以及它們層層之間的空隙。通過(guò)AFM和表面接觸角圖像的觀察可知：沉積SiOx后，(GO/PEI)nPLA薄膜的表面粗超度和對(duì)水的接觸角都增大了；相反，(m-GO/PEI)nPLA薄膜的則都是被減小了。增加SiOx層后有效阻隔了GO親水層對(duì)水分子的吸附，以此減少了(GO/PEI)nPLA薄膜的透濕量，當(dāng)n=16時(shí)，透濕量下降了41.63%；而(m-GO/PEI)n層本身有較好的疏水性，在沉積SiOx后(m-GO/PEI)nPLA薄膜的透濕性能沒(méi)有明顯的變化。
[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

本文編號(hào)：2367894