Micro-encapsulated phase-change materials (microPCMs) with Na2HPO4 center dot 12H(2)O encapsulated in poly(lactic acid) (PLA) shell were prepared by a solvent evaporation-precipitation method that involves the use of a coaxial needle. The effects of PLA concentration, stirring speed, injection rate of core and shell solutions, and polyvinyl alcohol (PVA) concentration on phase change properties were investigated. The thermal properties of microPCMs were characterized by differential scanning calorimetry (DSC). The capsules prepared under the optimal conditions are about 2 mm in diameter and show a latent heat of up to 122.2 J.g(-1). (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.