Dielectric-barrier discharge (DBD) is a typical non-equilibrium gas discharge with AC at low temperature and atmospheric pressure.In this paper the influence of DBD plasma on the crystallization of Cu(NO3)2· 3H2O is investigated.The experimental results show that DBD plasma has great influence on inducing the primary nucleation thus greatly reducing the nucleation time.Moreover

by applying DBD plasma

the morphology of Cu(NO3)2·3H2O was controlled during crystallization.In crystallization without DBD treatment

quadrilateral Cu(NO3)2·3H2O crystals were preferentially produced.However

if DBD plasma was applied during the nucleation process

the typical quadrilateral forms of crystal seeds transform to hexagonal crystals.The hexagonal crystals can grow to either hexagonal prism without further DBD plasma treatment or unique contact-twinned shaped hexangular star form under the environment of DBD plasma.