This thesis concerns with 4 basic aspects of the charge carrier transport: (1) depth of the potential well formed around the charge carrier when localized on a polymer chain; i.e. so called polaron binding energy. (2) Extent of the charge carrier delocalization over the polymer chain and influence of steric effects on this value. (3) Intrachain mobility of the charge carrier. (4) Effect of charge carrier transfer on the chain stability. Polysilanes, which are well known for their semi-conducting properties, were chosen as model material for investigation. Outlined properties were studied by means of quantum chemistry and molecular dynamics, which allowed us to investigate the process of the charge carrier transfer in great detail. Theoretical results were then compared to the experiments with very good agreement.

Dans ce travail, nous aborderons la manière dont les diverses logiques et stratégies d’entrée, de circulation et de flux frontaliers dans la région des Guyanes sont structurées. L’objectif est donc de comprendre la dynamique de circulation migratoire des Brésilien-ne-s au Suriname, mais aussi la place du Guyana et de la Guyane Française dans cette mobilité. Il s’agit alors d’analyser les logiques, les trajectoires et les dynamiques de mobilité des Brésiliennes travaillant dans la prostitution. La dynamique de mobilité liée à la prostitution est ici analysée à partir de l’expérience des personnes circulant dans l’univers du marché du sexe. Cette recherche est avant tout qualitative en ce qu’elle repose sur des entretiens semi-directifs réalisés avec 74 personnes (44 femmes, 27 hommes et 3 travestis/transsexuels) et s’appuie sur une approche ethnographique multi-située dans différents moments et lieux du Guyana, du Suriname, de la Guyane Française et de Hollande. Plus précisément, cette étude montre que les femmes passent par de multiples modalités d’échange : sexuels, affectifs, matériels, économiques et symboliques. Pour les Brésiliennes qui migrent au Guyana ou au Suriname pour travailler dans les clubs de prostitution, leur sortie de ces derniers constitue soit une transition entre la menina de club et la ploc, soit une relation avec un fixe ou un mari – ce sont là des catégories de référence pour comprendre le marché du sexe au Suriname et la dynamique migratoire de ces femmes dans la région des Guyanes. Or, chacune de ces catégories gravite autour du fait d’être femme et étrangère, d’être prostituée ou de passer par la prostitution, ou encore d’occuper d’autres rôles pour tenter de se détacher des étiquettes et des stigmates. / This work deals with the way in which the various logics and strategies of entry, circulation and border flow in the Guianas region are structured and aims to understand the dynamics of the migration of Brazilians in Suriname and the relation between this mobility and Guyana and French Guiana, to analyse the logics, circuits and mobility schemes of Brazilians in prostitution. The system of mobility linked to prostitution was analysed from the experience of people who lived the universe of the sex market or who were inserted in the circuit of this circulatory space. The study is mainly qualitative, based on semi-structured interviews with 74 people (44 women, 27 men and three transvestites/transsexuals) in a multi-sited ethnographic approach at various times and places in Guyana, Suriname, French Guiana and Holland. The study demonstrates that women transit between various modalities of exchange: sexual, affective, material, economic and symbolic; and that their mobility is frequent both in terms of spatial and labour movement. For the Brazilians who migrate to Guyana and Suriname to work in a prostitution club, the exit of the club means the transition between menina de club and ploc, or a relationship with a fixed or a husband, these are reference categories to understand the sex market in Suriname and their migratory dynamic in the Guianas region. Each of these categories revolves around the fact of being female and foreign, being a prostitute or going through the prostitution, or taking on other roles to try to distance themselves from labels and stigmata. / Este trabalho aborda a forma como são estruturadas as diversas lógicas e estratégias de entrada, de circulação e de fluxo fronteiriço na região das Guianas, e tem como objetivo compreender a dinâmica da circulação migratória de brasileiras/os no Suriname e a relação dessa mobilidade com a Guiana e a Guiana Francesa, analisar as lógicas, os circuitos e as dinâmicas de mobilidade de brasileiras na prostituição. A dinâmica de mobilidade ligada à prostituição foi analisada a partir da experiência das pessoas que vivenciaram o universo do mercado do sexo ou que estiveram inseridas no circuito desse espaço circulatório. O estudo é, sobretudo, qualitativo, realizado a partir de entrevistas semiestruturadas com 74 pessoas (44 mulheres, 27 homens e três travestis/transexuais), em uma abordagem etnográfica multissituada em diferentes momentos e lugares na Guiana, no Suriname, na Guiana Francesa e na Holanda. O estudo demonstra que as mulheres transitam entre várias modalidades de intercâmbio: sexuais, afetivos, materiais, econômicos e simbólicos; e que sua mobilidade é frequente tanto no que se refere à circulação espacial como à laboral. Para as brasileiras que migram para Guiana e o Suriname para atuar em clube de prostituição, a saída deste significa a transição entre menina de club e ploc, ou ter um fixo ou marido, categorias referenciais para compreender o mercado do sexo no Suriname e a dinâmica migratória delas na região das Guianas, uma vez que tais categorias giram em torno de ser mulher e estrangeira, de estar ou ser prostituta, de assumir outros papéis para tentar se distanciar de rótulos e estigmas.