Controllable phase segregation adjustment for immiscible polymer blends has always been tough, which hinders the development of amphiphilic antifouling coatings from more accessible blends. Herein, methacrylated poly(dimethylsiloxane) (PDMS-MA) was synthesized and mixed with poly(ethylene glycol) methylether methacrylate (PEG-MA). It was interestingly discovered that these PDMS-MA/PEG-MA blends displayed upper critical solution temperatures (UCST) due to thermo-induced conformational change of PEG-MA and the UCST changed with PDMS-MA/PEG-MA mass ratios. Micro-/nano-phase segregation, nanophase segregation, or homogenous morphology were therefore achieved. These PDMS-MA/PEG-MA blends with different mass ratios were UV-cured under varying temperatures to fabricate coatings. Their surface morphology and wettability are readily adjusted by phase segregation. For the first time, highly hydrophilic surface was achieved for coatings with microphase segregation because of the exposure of PEG-rich domains, which exhibited an enhanced protein resistance against bovine serum albumin (BSA). Anti-bacterial performance (Shewanella loihica) was also observed for these PDMS/PEG coatings. (C) 2016 Wiley Periodicals, Inc.