纳米聚多巴胺六方氮化硼–二氧化硅/环氧树脂涂层对水泥砂浆抗碳化能力的影响  

Effect of nano polydopamine hexagonal boron nitride-functionalised silicon dioxide/epoxy coating for resistance carbonation ability of cement mortar

作　　者：刘嘉源 张宏亮 左晓宝[1] 邹欲晓 LIU Jiayuan;ZHANG Hongliang;ZUO Xiaobao;ZOU Yuxiao(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学理学院,南京210094

出　　处：《复合材料学报》2023年第9期5046-5056,共11页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(52078252,51778297)。

摘　　要：为了获得具有良好分散性、填充性和阻隔性的纳米材料,同时将其作为填料以提升环氧树脂涂层对水泥砂浆试件的防护能力,本文制备了纳米聚多巴胺六方氮化硼–二氧化硅(PDABN-fSiO_(2))/环氧树脂涂层,涂覆于水泥砂浆试件表面,研究涂层对试件的防护效果。首先,利用盐酸多巴胺(DA)自聚合形成的聚多巴胺(PDA)与偶联剂(KH550),分别修饰纳米六方氮化硼(hBN)与纳米二氧化硅(SiO_(2)),获得纳米聚多巴胺六方氮化硼(PDABN)与功能化的SiO_(2)(fSiO_(2));其次,经聚合以制备纳米PDABN-fSiO_(2);最后,将其作为填料改性环氧树脂,并涂覆于水泥砂浆表面。通过FTIR、SEM-EDS和XPS等微观表征,观察并研究了纳米材料的微观特征;开展了碳化试验和涂层透气性试验,分析了纳米PDABN-fSiO_(2)对环氧树脂涂层的改性效果。结果表明:制备的纳米PDABN-fSiO_(2)具有“片层+颗粒”特殊结构,且在涂层中具有良好的分散性,可有效减缓其涂层中CO_(2)的渗透;同无填料涂层相比,涂覆有纳米PDABN-fSiO_(2)/环氧树脂涂层的水泥砂浆试件,在碳化7天、14天和28天时的碳化深度分别下降了68.7%、72.9%和64.8%,其涂层在48 h的透气性降低了34.7%。因此,纳米PDABN-fSiO_(2)掺入环氧树脂涂层后,明显地提高了涂层水泥砂浆试件的抗碳化能力,并降低了环氧树脂涂层的透气性。In order to obtain nanomaterials with better dispersal,filling and barrier properties,which were used as fillers to enhance the protection of the epoxy coatings for cement mortar,the polydopamine(PDA),which was prepared by self-polymerization of dopamine hydrochloride(DA)and silane coupling agent(KH550),was utilized to modify nano hexagonal boron nitride(hBN)and nano silicon dioxide(SiO_(2)),respectively,to obtain two nanomaterials polydopamine hexagonal boron nitride(PDABN)and functionalised SiO_(2)(fSiO_(2))by polymerization reactions.A new nanomaterial,polydopamine hexagonal boron nitride-functionalised silicon dioxide(PDABN-fSiO_(2)),was synthesized,and it was mixed with epoxy to prepare a modified coating.The coating was covered on the surface of cement mortar to enhance its carbonation resistance.The microscopic characteristics of nano materials were observed by FTIR,SEM-EDS and XPS.The modified effect of epoxy coating by nano PDABN-fSiO_(2)was analyzed by carbonation experiments and permeability tests.Results indicate that the prepared nano PDABN-fSiO_(2)has a layer-particle structure and better dispersion in coating,which can effectively slow down the penetration of CO_(2)in the coating.Compared with the blank coating,the carbonation depth of the cement mortar coated with nano PDABNfSiO_(2)/epoxy coating is decreased by 68.7%,72.9%and 64.8%at 7,14 and 28 days of carbonation,respectively,and the permeability of its coating is decreased by 34.7%at 48 hours.Thus,the epoxy coating with nano PDABN-fSiO_(2)can significantly improve the carbonation resistance of cement mortar and reduce its permeability.

关 键 词：纳米聚多巴胺六方氮化硼(PDABN)-功能化的SiO_(2)(fSiO_(2)) 环氧树脂涂层 微观表征 碳化 透气性 

分 类 号：TU593[建筑科学—建筑技术科学] TB332[一般工业技术—材料科学与工程]