Study on the Preparation of Hierarchical Porous Materials by Particle Stabilized Soft Matter Templating and Employing as Supportings for Phase Change Materials

Author:Li Ya Li

Supervisor:li jin hong


Degree Year:2019





In this paper,the structure of the novel porous material was designed by the particlestabilized soft matter system,and is applied as the carrier of the phase change energy storage material.The difficulty of the particle-stabilized soft matter system lies in how to stabilize the particles at the gas/water or oil/water interface for a long time.For which,the main research are divided into high-solid content particle-stabilized Pickering foam,high-solid content particle-stabilized Pickering emulsion and low solid content particles-stabilizes Capillary foam soft matter system.Using inorganic Ti O2,Al2O3 particles and organic cellulose particles,polyethylene(PE),polyvinyl chloride(PVC)particles as the raw materials,using three kinds of particles stabilized soft matter system to prepare hierarchical porous structure materials.Pickering foam has an air/water/particle interface.Modified Al2O3 particles with size of 500 nm and sucrose are used as raw materials,graphite @Al2O3 hierarchical porous material(PACF)with a three-dimensionally connected hierarchical pore structure was constructed in situ,and also,the pore structure was controlled by changing the amount of sucrose,the graphite structures were controlled by the sintered temperature.Moreover,PACFs were studied as carrier for phase change material(PCM),and successfully prepared shape-stable paraffin/PACF.In Pickering emulsion,the surface tension of the oil/water interface is much lower than that of air/water.Solid content of the Ti O2 particle(size: 23 nm)stabilized Pickering emulsion is 20-35 wt%,wherein,particles was modified.The prepared porous Ti O2 ceramics(PTF)were used to prepare the paraffin/PTF(PTFP)as a carrier material.In order to increase the thermal conductivity and specific surface area of the PTF,sucrose was added to the solution and carbonized in situ to form C/PTF(PTFC).As we know,particle-stabilized Pickering foam systems are only suitable for hydrophobic particles,thus usually required surface modified particles.A new class of Capillary foams,which are formed by the adsorption of low solids content particles on the surface of the oil-coated bubbles,were studied.Since the particles are more easily adsorbed at the oil/water interface than the air/water interface,thus this system greatly broadens the application of particles with different surface properities.We used hydrophilic HP55 and hydrophobic EC cellulose particles as stabilizers,and successfully got the long-term particle stabilized Capillary foams proved that the Capillary system has a wide selection of particles.And also,the effects of oil type,p H and ionic strength on foam stability were also investigated.In addition,we prepared dry lightweight Capillary foams under the synergy of PE and PVC particles with TMPTMA,and explored their application properties as support materials for the two kind of phase change materials(paraffin and PEG2000).