In the emerging knowledge economy, scientific pursuit in the form of international collaboration has escalated. Studies consistently report that such collaboration, which has been intensifying in the last several decades, is common among not only advanced economies but also in emerging scientific nations such as China, India, and Brazil. The emergence of a "new invisible college" of international knowledge exchange has aroused interest from social scientists and captured the attention of policymakers. Indeed, recognizing its importance as a means of monitoring and exploiting other countries' R&D investment, more and more countries champion and participate in international joint research. International collaboration between the United States (US) and China is particularly interesting. The US has been and will continue to be the leader in scientific development for the foreseeable future. However, as a rising scientific power, China is changing the global landscape of ideas and innovation along with other emerging countries. The growing significance of the US-China relationship and worldwide interest in China's development suggest that the characteristics of the scientific collaboration of these two countries and its associated knowledge dissemination across national borders are timely topics to study. Surprisingly, few studies have examined research collaboration between a scientific superpower and an emerging scientific power, particularly in the context of emerging state-of-the-art technology. This dissertation seeks to address this research gap by examining patterns of collaboration in the US-China scientific community and its impact on China's rapid knowledge accumulation in nanotechnology, if any, through Chinese knowledge moderators (CKMs)--Chinese scholars who bridge two otherwise distant scientific communities through intensive collaboration with both sides. The research focuses on the following three aspects: firstly, built upon the notions of the boundary spanner and the structural hole, the study develops the concept of Chinese knowledge moderators and uses it as an instrument to examine the relationship between international collaboration and knowledge spillover across national boundaries. Secondly, it operationalizes and tests the impact of US-China collaboration using multiple methods. In addition to citation-based indicators, based on the turnover of nanotechnology keywords, the study investigates the impact of collaborating with US scholars on CKMs' research trajectory and the international knowledge spillover facilitated by CKMs. Thirdly, utilizing a longitudinal publication dataset of 77 CKMs and their CV data, this study is able to quantify the dynamic impact of US collaboration on the quality of CKMs' research over time. The combination of bibliometric analyses, empirical testing, and case studies allows for the development of a comprehensive blueprint of US-China scientific collaboration in the field of nanotechnology. This research yields several significant findings. First, the evolution of US-China collaboration in nanotechnology has gone beyond quantitative growth, as qualitative and structural changes have begun to take place. Secondly, CKMs play a critical role in fostering China's nanotechnology development, manifested in both knowledge creation and knowledge diffusion. The present study also reveals that US-China collaboration has a diminishing effect over time on the research quality of CKMs at level of individual papers, but as pertaining to entire journals. Thirdly, the case studies on the evolution of research streams suggest that US-China collaboration influences the research trajectory of CKMs, who, as the conduits of knowledge, further disseminate it within the national boundaries of China. The research also has policy implications for both sides. Chinese policy makers need to strengthen the mechanisms that encourage CKMs collaborating with the US, and, in order to amplify international knowledge spillover, these mechanisms should further encourage more interactions between CKMs and their Chinese domestic colleagues. From the US American perspective, given China's scientific emergence in nanotechnology, the US should direct its efforts to ensuring its ample access to exploiting the heavy R&D investment of this emerging scientific powerhouse by collaborating with top Chinese scientists.