Translocation of a polymer chain under geometric confinement

Abstract

ENGLISH ABSTRACT: The advent of the synthesis or manufacturing of controlled structures on submicron scales as well as experimental developments enabling the investigation of physics in speci c biological systems at extremely small length scales underlines the need for dealing with the statistical physics of small systems which are geometrically con ned. A typical example of a system for which physical questions can be answered by means of theoretical modelling is the virus, where polymer genetic material is encapsulated in a protein shell. In this project the role of con nement on polymer chains will be investigated. We investigate how the translocation of polymer from one region to another through a small opening depends on various electrolytic, polymer concentration and wall interaction conditions. This is an extension of the simple, purely entropic, picture in that the interaction terms enter the picture. We employ a variational scheme in deriving our results.

AFRIKAANSE OPSOMMING: Sowel die moontlikheid van beheerbare sintese of vervaardiging van strukture op sub-mikrometer lengteskale asook die koms van eksperimentele metodes vir die ondersoek van biologiese stelsels op baie klein lengteskale onderstreep hoe nodig dit is om die statiestiese sika van klein stelsels met geometriese beperkings te verstaan. 'n Tipiese voorbeeld waar teoretiese metodes vir siese vrae aangewend word is 'n virus, waar die polimeriese genetiese materiaal in 'n proteïen skil beweeg. In die huidge projek word die rol van 'n spesi eke geometriese beperking op polimeerkettings ondersoek. Ons ondersoek hoe die oorplasing van 'n polimeer deur 'n klein opening van een gebied na die ander deur verskillende elektrolietiese, polimeer-konsentrasie en wandinteraksie eienskappe afhang. Dit is 'n uitbreiding van die eenvoudige, volledig entropiese beeld vir oorplasing deurdat wisselwerkings ingesluit word. 'n Variasiebeginsel word aangewend om die resultate af te lei.