超低掺量氧化石墨烯的分散行为及其对水泥基材料结构与性能的影响

Dispersion behavior of ultra-low dosage graphene oxide and its effect on structures and performances of cement-based materials

研究了氧化石墨烯(GO)纳米片层在水相及分散剂作用下的存在状态及分散行为,发现GO在水泥基材料中存在掺量大、成本高及应用效果不稳定不显著的主要原因是:GO纳米片层容易团聚导致其在水泥基体中分散不均匀。为此制备了两性聚羧酸分散剂(APC)及与GO的复合物(APC-GO),研究发现GO在APCGO复合物中不再以团簇式聚集态存在,而是主要吸附在APC多支链分子上并呈现多支链状的分散状态,通过掺入APC-GO复合物引入与水泥质量比为0.0003%的超低掺量GO,能够显著提高水泥基材料的力学性能和耐久性。SEM显示掺入APC-GO的水泥基材料具有规整致密的微观结构形貌,说明了GO在水泥基体中能够均匀分散,且对水泥水化产物的形貌和结构具有规整性调控效果,研究结果对GO在水泥基材料中的应用具有指导意义。

The existence state and dispersion behavior of graphene oxide(GO)nanosheets in aqueous phase and dispersant were studied.It is found that the main reason for the large dosage,high cost and unstable and insignificant application effect of GO when it is applied to cement-based materials is that GO nanosheets are easy to agglomerate and cannot be evenly dispersed in the cement matrix.Amphoteric polycarboxylate dispersant(APC)and its composite with GO(APC-GO)were prepared.The result finds that GO no longer exists in the cluster state in APCGO composite,and is mainly adsorbed on APC multi-chain molecules and presents a multi-chain dispersion state.The mechanical properties and durability of cement-based materials can be significantly improved by the addition of APC-GO composite with ultra-low content(mass ratio to cement)of GO of 0.0003%.SEM results show that cement-based materials have regular and compact microstructure morphology.The results show that GO can be uniformly dispersed in cement matrix and has regular regulation effect on the morphology and structure of cement hydration products.The research results have guiding significance for the application of GO.