Investigation of Phase Change Material Encapsulation by Complex Coacervation

Autor(es)

Veiga Ribeiro, Lucas Fagundes ; Silva, Vanessa Martins ; Prata Soares, Ana Silvia

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF COLLOID SCIENCE AND BIOTECHNOLOGY; v. 2, n. 2, p. 8-pg., 2013-06-01.

Resumo

Two potential phase change materials (PCMs) were microencapsulated by complex coacervation with gelatin- gum arabic and the characteristics of these microparticles were investigated. Methyl-palmitate and paraffin wax were used as core material, since they provide two different melting points ( around to 30 degrees C and 50 degrees C, respectively). The protective barrier provided by microencapsulation prevents the material from sticking on and spreading out the surrounding material during the phase change. These systems can be applied in solar systems or building materials and textiles, for heat storage and release. Some operational variables were investigated to select suitable production conditions for paraffin wax: temperature, surfactant addition, time of addition and amount of core material. The encapsulation ratio (ER%) of these systems was indirectly determined by differential scanning calorimetry (DSC). As results, an increased core to coating ratio from 50 to 75% and the ER raised from 25% to 50%. The paraffin influenced the complexation of the polymers and with the largest amount of this hydrocarbon, about 39% of the polymer was not complexed. The use of methyl palmitate did not have this influence on the coacervation process. Energy storage capacities of 58.49 J g(- 1) and 107 J g(- 1) were observed, respectively, for paraffin wax and methyl palmitate systems, indicating the potentiality of both for use as energy storage systems. The melting point of microcapsules produced with paraffin was 46 degrees C, and with methyl palmitate was 28 degrees C, both near of the melting point of the pure compounds. The average particle size of the paraffin and methyl palmitate microcapsules obtained was 69.43 mu m and 111.55 mu m, respectively. (AU)

• Processo FAPESP: 11/04230-5 - Projeto de partículas para o acabamento funcional de têxteis: investigação de técnicas de microencapsulação
• Beneficiário: Ana Silvia Prata
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores