Mapping China’s New Materials Industry Chain for Sustainable Development: Evidence from Listed-Firm Investment-Based City Association Networks

Understanding the spatial organization of the new materials industry chain is essential for promoting sustainable industrial development. However, existing research rarely examines it as an integrated intercity network spanning multiple segments and specialized sub-sectors. To address this gap, this study constructs the New Materials City Association Network (NM-CityNet) using firm-level cross-regional equity investment data for 294 Chinese cities from 2010 to 2024. NM-CityNet includes two dimensions: segment networks (upstream, midstream, downstream) and sub-sector networks (advanced basic materials, critical strategic materials, and frontier new materials). A chain-lock model is applied, combined with social network analysis and the quadratic assignment procedure. Location quotients are integrated with weighted degree to capture specialized division-of-labour patterns. Using these methods, this study reveals the regional distribution, network structure, specialization patterns, and formation mechanisms of NM-CityNet. Results show that: (1) upstream core cities cluster in eastern China, midstream activities diffuse toward central and western regions, and downstream activities concentrate along the south-eastern coast; (2) NM-CityNet remains sparse and shows clear community structures, while different segments form differentiated spatial organization mechanisms; (3) sub-sectors exhibit clear specialization, with critical strategic materials showing broader spatial coverage; (4) drivers are heterogeneous: administrative proximity promotes link formation; government S&T financial-support differences are positively associated with link formation, although this association may partly reflect selective investment effects; economic and transport disparities inhibit link formation; innovation differences matter only in the midstream segment; and resource-endowment differences matter upstream and downstream.