In Situ Preparation And Antibacterial Activity Of Metal-organic Frameworks/Pulp Fibers Composite

HKUST-1/pulp fibers composite and ZIF-8/pulp fibers composite were in site prepared in this paper. The morphology and specific functional groups of composite were analyzed by SEM-EDX, XRD and FTIR. Besides, the deposition ratio, tensile strength and antibacterial activity were also determined with different conditions.In the research of HKUST-1/pulp fibers composite, the copper-based metal-organic framework materials, HKUST-1, was in situ generated on the surface of pulp fibers, in which Cu2+ and 1,3,5-benzenetricarboxylic acid were used as metal ion and organic ligand, respectively, and ethanol was utilized as the solvent of organic ligand. SEM observation showed HKUST-1 was existed on the pulp fiber surface as micro-rods, and the existence of HKUST-1 was further demonstrated by XRD, FTIR and EDX. The deposition ratio, tensile strength and antibacterial activity were also evaluated on the aspect of dosage of Cu(Ac)2, absorption time, reaction time and reaction temperature. The results revealed that Cu(Ac)2 dosage had the critical impact on the above performances. When it reached 3 mmol, the deposition ratio and antibacterial activity were optimal but the tensile strength was the lowest. On the other hand, temperature showed little impact and absorption time, reaction time had almost no influence. In summary, the optimum preparation conditions were:H3BTC of 2 mmol, Cu(Ac)2 of 3 mmol, absorption time of 10 min, reaction time of 5 min and reaction temperature of 25 ℃. In addition, it was confirmed through the research on the antibacterial activity of the composite that the composite could inhibit the growth of E. coli and S. aureus while the original pulp fibers and H3BTC couldn’t inhibit their growth, which indicated that the antibacterial activity was attributed to copper ions.In the research of ZIF-8/pulp fibers composite, the zinc-based metal-organic framework materials, ZIF-8, was in situ generated on the surface of pulp fibers, in which Zn2+ was used as metal ion and 2-methylimidazole with deprotonation pretreatment of NaOH was used as organic ligand. The result of SEM revealed that ZIF-8 appeared on the surface of pulp fiber with the morphology of nanoparticles. Otherwise, the existence of ZIF-8 was further characterized by FTIR,XRD and EDX. Through the evaluation of deposition ratio, tensile strength and antibacterial activity from the aspect of dosage of NaOH and Zn(Ac)2, absorption time, reaction time and reaction temperature, it was concluded that the 2-methylimidazole was completely deprotonated with 4 mmol NaOH, which showed the highest deposition ratio and antibacterial activity with the worst tensile strength. Zn(Ac)2 as reactant could significantly affect the properties of composite, and their values were the optimal when Zn(Ac)2 reached 2 mmol. Temperature had weak impact and absorption time and reaction time had almost no influence on the properties of composite. In summary, the optimum preparation conditions were:NaOH of 4mmol,2-methylimidazole of 4 mmol, Zn(Ac)2 of 2 mmol, absorption time of 10 min, reaction time of 10 min and reaction temperature of 25 ℃. In the other hand, it was confirmed through the research on the antibacterial activity of composite that the composite could inhibit the growth of E. coli and S. aureus while the original pulp fibers and deprotonated 2-methylimidazole couldn’t inhibit their growth, which concluded that the antibacterial activity was due to the abundant zinc ions in ZIF-8.With the comparison between two kinds of the composites, ZIF-8/pulp fibers composite had obvious advantages on process realizability, deposition efficiency, antibacterial activity and so on.