Effect of Substrate on Nucleation Rate of Two-Dimensional Colloidal Crystals
Effect of Substrate on Nucleation Rate of Two-Dimensional Colloidal Crystals
复制标题
DOI：
10.1021/acs.cgd.9b00069
复制
发表时间：
2019-06-01
影响因子：
3.8
通讯作者：
Uda, Satoshi
中科院分区：
文献类型：
--
作者：
Guo, Suxia;Nozawa, Jun;Uda, Satoshi
研究了衬底对胶体晶体非均匀二维成核的影响。测量未涂覆的盖玻片、Pt涂覆的盖玻片和Au涂覆的盖玻片上的2D胶体晶体的成核速率J。在三种基板中，未涂覆的盖板玻璃的J被发现是最大的，而在相同的过饱和条件下，Pt涂覆的盖板玻璃的J是最小的。的界面自由能的变化，Δ Σ，是从基于经典成核理论（CNT）的成核速率，表明未涂覆的盖板玻璃具有最小的Δ Σ，而它是最大的Pt-涂覆的盖板玻璃。由于Delta sigma来源于原子晶体中的键能，我们推断它与胶体系统中胶体颗粒与基底之间的相互作用有关。胶体颗粒（聚苯乙烯）和每个基板之间的相互作用，确定与表面力测量使用原子力显微镜（AFM）。结果表明，颗粒与未镀膜玻璃之间的粘附力最弱，主要由货车范德华力组成，而镀铂玻璃的粘附力最强。胶体粒子与基质之间的吸引力越大，则Δ sigma越大，J越小。胶体粒子与基质之间的相互作用对胶体晶体的异质成核速率有很大的影响。
The effect of a substrate on the heterogeneous two dimensional (2D) nucleation of colloidal crystals has been investigated. Nucleation rates, J, of 2D colloidal crystals on uncoated cover glass, Pt-coated cover glass, and Au-coated cover glass are measured. Among the three substrates, the J of the uncoated cover glass is found to be the largest, while it is smallest for the Pt-coated cover glass under the same supersaturation conditions. The interfacial free energy change, Delta sigma, is obtained from the nucleation rate based on classical nucleation theory (CNT), indicating that uncoated cover glass possesses the smallest Delta sigma, while it is largest for the Pt-coated cover glass. Since Delta sigma originates from the bond energy in atomic crystals, we deduce that it is related to the interaction between colloidal particles and the substrate in a colloidal system. The interactions between a colloidal particle (polystyrene) and each substrate are determined with surface force measurements using atomic force microscopy (AFM). The results show that the adhesive force, which predominantly consists of the van der Waals force, between particles and uncoated cover glass, is the weakest, while that for the Pt-coated cover glass is the strongest. A larger attractive interaction between the colloidal particles and the substrate yields a higher Delta sigma, and thus a smaller J. The interaction between particles and substrate has a great influence on the heterogeneous nucleation rate of colloidal crystals.