Caetano Daniel L Z, de Carvalho Sidney J
Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Rua Cristovão Colombo 2265, Jd. Nazareth, 15054-000, São José do Rio Preto, São Paulo, Brazil.
Eur Phys J E Soft Matter. 2017 Mar;40(3):33. doi: 10.1140/epje/i2017-11525-5. Epub 2017 Mar 27.
Polyampholytes are polymers that have positive and negative monomers along their chain. The adsorption of polyampholytes on charged surfaces has been the subject of a large number of theoretical, computational and experimental studies due to its importance in a variety of bio and nanothechnological systems. However, computational studies focusing on interaction between polyampholytes and cylindrical charged surfaces are rather scarce. This study, therefore, aims to investigate the conformational properties of block-polyampholytes in the presence of a negatively charged cylinder by means of Metropolis Monte Carlo simulations. Adopting a simplified model in which the electrolyte solution is treated at the Debye-Hückel level, the effects of the ionic strength, the linear charge density of the cylinder and the block length on monomers distributions have been investigated. It was found that increasing the salt concentration promotes a transition from a conformation characterized by large loops to a necklace-like conformation parallel to the surface. It was also shown that, at low cylinder charge density, the increase in salt concentration and the length of the blocks lead to a change in the orientation of the adsorbed chain.
聚两性电解质是一种聚合物，其链上含有带正电和负电的单体。由于聚两性电解质在各种生物和纳米技术系统中的重要性，其在带电表面的吸附一直是大量理论、计算和实验研究的主题。然而，专注于聚两性电解质与圆柱形带电表面之间相互作用的计算研究相当匮乏。因此，本研究旨在通过 metropolis 蒙特卡罗模拟研究在带负电圆柱体存在下嵌段聚两性电解质的构象性质。采用一种简化模型，其中电解质溶液在德拜-休克尔水平上进行处理，研究了离子强度、圆柱体的线性电荷密度和嵌段长度对单体分布的影响。研究发现，增加盐浓度会促使构象从以大环为特征的构象转变为平行于表面的项链状构象。研究还表明，在低圆柱体电荷密度下，盐浓度和嵌段长度的增加会导致吸附链的取向发生变化。
