Amphiphilic Block Copolymer‐Functionalized VO 2 Nanocomposites for Smart Waterborne Polyurethane Coatings

ABSTRACT Aqueous vanadium dioxide (VO 2 )‐based smart thermal insulation coatings represent a viable strategy to decrease building energy consumption and advance sustainable development goals. However, the inherent instability and limited compatibility with polymer matrices of VO 2 hinder its widespread application. Herein, a core‐shell structured nanocomposite, VO 2 @poly(hexafluorobutyl methacrylate‐ block ‐ N , N ‐dimethylacrylamide) (VO 2 @PHFBMA‐ b ‐PDMA), is developed and applied to water‐based intelligent coatings. The experimental results show that the designed block copolymer shell PHFBMA‐ b ‐PDMA not only has excellent acid and oxidation resistance but also improves the water dispersion stability of VO 2 , ensuring the compatibility between VO 2 and the organic polymer matrix. Moreover, the shell can effectively increase the carrier concentration in VO 2 , thereby significantly enhancing the local surface plasmon resonance effect and giving it excellent optical performance. By optimizing the formula and incorporating the VO 2 @PHFBMA‐ b ‐PDMA nanocomposites into water‐based polyurethane resins, the resulting coating exhibits excellent adhesion, high hardness, and strong resistance to thermal cycling and ultraviolet aging. In addition, the coating has significant thermochromic properties, which can transmit near‐infrared radiation at low temperatures and effectively shield near‐infrared radiation at high temperatures. Compared with uncoated glass, the designed coated glass can reduce indoor temperature by approximately 5°C.