Preparation and structure performance regulation of paraffins/TOCNF phase change aerogels
To prevent liquid leakage in solid-liquid phase change materials,improve the stability of phase change materials,reduce the agglomeration and increase the heat transfer surface area,the article,took TEMPO-oxidized cellulose nanofibers(TOCNF)as the stabilizer and paraffins as the oil phase,prepared the paraffins/TOCNF phase change aerogels(PTA)by freeze-drying after obtaining paraffins/TOCNF Pickering emulsion(PTPE)at high speed and mixing it with TOCNF,the main body of the aerogel.The effects of TOCNF concentration and solution pH value on the morphology and stability of the Pickering emulsion,the morphology structure,heat storage capacity,thermal stability and mechanical properties of PTA with different amounts of Pickering emulsion were studied.The results showed that when the mass fraction of TOCNF emulsifier was 0.5%and pH was within 7-11,the Pickering emulsion had small and uniform size,with the average particle size distribution ranging from 8.3 μm to 14.8 μm,indicating excellent stability.After emulsification and dispersion,paraffin particles were evenly embedded on the surface of PTA hole wall without liquid leakage.The latent heat value of PTA could be as high as 225.8 J/g indicating good mechanical properties.It can be seen that the phase change aerogel with a three-dimensional porous network structure prepared by the Pickering emulsion template method using TOCNF as the emulsifier and the skeleton of aerogels solves the problems of liquid leakage,low latent heat,and poor mechanical strength existing in the current cellulose composite phase change aerogels to some extent.