Studies On HKUST-1/zeolite Beta Composites And Hydrophobicity Modification Of HKUST-1

In recent years,metal-organic frameworks(MOFs)materials are emerging as a functional porous material.They have high specific surface area and porosity,and tunable chemical functionality.Their unique characteristics make them be widely studies and used in catalysis,adsorption and separation,drug delivery,bio-sensing,and etc.Unfortunately,MOFs have some shortages such as poor stability and mechanical strength,which limit their practical applications.Especially,most MOFs with weak metal-ligand coordination bonds are more or less vulnerable to water molecules under an ambient atmospheric environment.Recently,the preparation of composites based on metal-organic frameworks and their modification to improve the stability of the MOFs material have become the research hotspots in the MOFs material field.Herein we successfully prepared zeolite beta microsphere@HKUST-1 core-shell composites by a step-by-step seeding procedure with zeolite beta as core and fabricated HKUST-1@nanosized zeolite beta composites with octahedron-shaped HKUST-1 as support.The HKUST-1 and zeolite beta composites were applied to remove thiophene from isooctane solution and indole from isooctane solution.Results showed that the composite materials exhibited excellent adsorption capacity and rate when the concentration of sulfur was less than 300 ppm or the concentration of nitrogen was at 100 ppm.The HKUST-1@nanosized zeolite beta composite which contained 68.5 wt% HKUST-1 had a better adsorption capacity than bare HKUST-1 when the initial S-content was below 300 ppm,and a comparable adsorption capacity when the initial S-content was above 300 ppm for a model oil composed of thiophene and isooctane.In addition,the post-synthesis hydrophobicity modification of HKUST-1 using polydimethylsiloxane thermal deposition modification and ligand exchange method was also investigated.The results show that the polydimethylsiloxane-modified HKUST-1 has better hydrophobicity without a decrease in the specific surface area.