关键词: 复合材料, 膜, 制备, 空气除湿, 水蒸气透过性, 氯化锂

Abstract:

In order to improve dehumidification efficiencies of membrane-based energy recovery ventilator(ERV), composite membranes based on cellulose acetate, sodium alginate and lithium chloride(LiCl) were fabricated.Cellulose acetate was adopted as supporting constructions and sodium alginate and LiCl were the corresponding active layer and hydrophilic additive.Then their key characteristics were tested and analyzed to investigate practical performance in the ERV.The highest permeance of composite membranes reaches up to 4.42×10^-5g·m^-2·s^-1·Pa^-1, which is 1.56 and 2.63 times higher than those of the asymmetric membrane without LiCl and the traditional commercial paper, respectively.Water solubility of the modified active layer ranges from 18.29% to 28.55% for cross-linking improves the waterproofness.Moreover, thermal gravity curves indicate membranes can be regenerated by contacting 55℃ dry air.Fourier transform infrared spectra illustrates that there are plenty of hydrophilic hydroxyl groups on the surface of composite membranes.Finally, the total mass transfer of ERV composed by the composite membranes is analyzed and compared with the commercial one.These properties demonstrate this membrane has great potential to be applied on the ERV.

Key words: composites, membranes, preparation, air dehumidification, water vapor permeance, lithium chloride