Direct conversion of cellulose into 5-hydroxymethylfurfural(HMF) was performed by using single or combined metal chloride catalysts in 1-ethyl-3-methylimidazolium chloride(Cl) ionic liquid.Our study demonstrated forma...Direct conversion of cellulose into 5-hydroxymethylfurfural(HMF) was performed by using single or combined metal chloride catalysts in 1-ethyl-3-methylimidazolium chloride(Cl) ionic liquid.Our study demonstrated formation of 2-furyl hydroxymethyl ketone(FHMK),and furfural(FF) simultaneously with the formation of HMF.Various reaction parameters were addressed to optimize yields of furan derivatives produced from cellulose by varying reaction temperature,time,and the type of metal chloride catalyst.Catalytic reaction by using FeCl3 resulted in 59.9% total yield of furan derivatives(HMF,FHMK,and FF) from cellulose.CrCl3 was the most effective catalyst for selective conversion of cellulose into HMF(35.6%) with less concentrations of FHMK,and FF.Improving the yields of furans produced from cellulose could be achieved via reactions catalyzed by different combinations of two metal chlorides.Further optimization was carried out to produce total furans yield 75.9% by using FeCl3/CuCl2 combination.CrCl3/CuCl2 was the most selective combination to convert cellulose into HMF(39.9%) with total yield(63.8%) of furans produced from the reaction.The temperature and time of the catalytic reaction played an important role in cellulose conversion,and the yields of products.Increasing the reaction temperature could enhance the cellulose conversion and HMF yield for short reaction time intervals(5~20 min).展开更多
Carboxymethyl cellulose hydrogels were developed through crosslinking process using eco-friendly crosslinkers such as maleic,succinic,and citric acids.Carboxymethyl cellulose was prepared from the cellulosic fraction ...Carboxymethyl cellulose hydrogels were developed through crosslinking process using eco-friendly crosslinkers such as maleic,succinic,and citric acids.Carboxymethyl cellulose was prepared from the cellulosic fraction of olive industry residues.A series of hydrogels with varying crosslinker acid concentrations,reaction times,and reaction temperatures was produced to study the swelling capacities and gel fraction of the obtained hydrogels.Additional study pertains to the preparation of antimicrobial nanocomposite hydrogels through in-situ incorporation of the silver nanoparticles during the crosslinking reaction.Silver nanoparticles were prepared by reduction of AgNO3 with leaves of Ricinus communis.The particle size of prepared silver nanoparticles was detected by transmission electron microscopy(TEM).Chemical structure and morphological characterizations of the prepared hydrogels were performed using Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),and energy-dispersive X-ray spectroscopy(EDX).Finally,the antimicrobial activity of the loaded silver hydrogels against Gram negative(G-ve),Gram positive(G+ve),and Candida albicans yeast was demonstrated.展开更多
基金U.S.DOE through Sustainable Energy Research Center(SERC)at Mississippi State University(DE-FG36-06GO86025)
文摘Direct conversion of cellulose into 5-hydroxymethylfurfural(HMF) was performed by using single or combined metal chloride catalysts in 1-ethyl-3-methylimidazolium chloride(Cl) ionic liquid.Our study demonstrated formation of 2-furyl hydroxymethyl ketone(FHMK),and furfural(FF) simultaneously with the formation of HMF.Various reaction parameters were addressed to optimize yields of furan derivatives produced from cellulose by varying reaction temperature,time,and the type of metal chloride catalyst.Catalytic reaction by using FeCl3 resulted in 59.9% total yield of furan derivatives(HMF,FHMK,and FF) from cellulose.CrCl3 was the most effective catalyst for selective conversion of cellulose into HMF(35.6%) with less concentrations of FHMK,and FF.Improving the yields of furans produced from cellulose could be achieved via reactions catalyzed by different combinations of two metal chlorides.Further optimization was carried out to produce total furans yield 75.9% by using FeCl3/CuCl2 combination.CrCl3/CuCl2 was the most selective combination to convert cellulose into HMF(39.9%) with total yield(63.8%) of furans produced from the reaction.The temperature and time of the catalytic reaction played an important role in cellulose conversion,and the yields of products.Increasing the reaction temperature could enhance the cellulose conversion and HMF yield for short reaction time intervals(5~20 min).
文摘Carboxymethyl cellulose hydrogels were developed through crosslinking process using eco-friendly crosslinkers such as maleic,succinic,and citric acids.Carboxymethyl cellulose was prepared from the cellulosic fraction of olive industry residues.A series of hydrogels with varying crosslinker acid concentrations,reaction times,and reaction temperatures was produced to study the swelling capacities and gel fraction of the obtained hydrogels.Additional study pertains to the preparation of antimicrobial nanocomposite hydrogels through in-situ incorporation of the silver nanoparticles during the crosslinking reaction.Silver nanoparticles were prepared by reduction of AgNO3 with leaves of Ricinus communis.The particle size of prepared silver nanoparticles was detected by transmission electron microscopy(TEM).Chemical structure and morphological characterizations of the prepared hydrogels were performed using Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),and energy-dispersive X-ray spectroscopy(EDX).Finally,the antimicrobial activity of the loaded silver hydrogels against Gram negative(G-ve),Gram positive(G+ve),and Candida albicans yeast was demonstrated.
