This thesis offers a mixed-method exploratory investigation of global scientific mobility. Contextualised as an important factor in the development of national capacities in science and innovation, global scientific mobility has so far remained a relatively underdeveloped subject in current scholarship. In this doctoral research, the focus on the impact of global scientific mobility that entails change of affiliation on (1) research practice, in particular, boundaries of academic activities, and (2) career development trajectories, increasingly affected by globalisation, is assumed. This research responds to the interest among academic and policy communities in the role of human resources in science-driven economic growth. It integrates three sets of literature, encompassing systems approach to studying learning and innovation; transnational approach to migration studies, and social studies of science that focus on academic citizenship, to explain global transformations in scientific mobility flows across countries and regions; and the post-migration impact of scientists in host organisations and communities. Empirically, this research focuses on career trajectories and elements of academic practice of Russian-speaking nanoscientists educated in post-Soviet countries and working abroad. The Soviet Union was an internationally isolated research system and developed peculiar norms of organisation, communication and governance of science. After the breakdown, post-Soviet countries experienced large-scale human capital flight. Nanotechnology is a generic technology, thought to aggregate advanced use-inspired areas of physics, chemistry and engineering. Around the world, nanotechnology has significant political importance. Policy and public-driven emerging technology agendas reveal contribution of competent post-Soviet scientists, but also elicit differences in approaches and rewards. This study finds significant transformations in scientific mobility flows caused by globalisation-induced opportunities. As relocation becomes easier to accomplish, scientists increasingly build their careers not only in multiple organisations, but also in multiple countries. At the same time, national differences in career development paths and norms of academic community membership have significant influence on career development opportunities of scientists. However, unique skills developed during mobility open up alternative options for globally mobile Russian-speaking nanoscientists, such as engagement in transnational science diaspora networks. This research contributes to understanding of scientific mobility as a simultaneous, continuous, network-based process. It further provides insight into development of multidisciplinary research area that encompasses broader understanding of roles, activities, contributions and opportunities of foreign-born scientists in the globalising world.