Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperatu...Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperature on the extent of amination. And the molecular simulation technology was adopted to analyze the conformation stability of aminate （AKGM）. The results indicate that when the amount of CEA is higher, the extent of amination is higher. The optimum concentration of NaOH, reaction time and temperature are 10% NaOH, 70 ℃ and 45 rain, respectively. IR shows KGM is successfully aminated. The conformation of AKGM is in a random clew-like shape.展开更多
Konjac glucomannan(KGM) has been generally used in food,film-former and biomedical applications,especially in the edible packing films due to its excellent film-forming ability,good biocompatibility and biodegrade-abi...Konjac glucomannan(KGM) has been generally used in food,film-former and biomedical applications,especially in the edible packing films due to its excellent film-forming ability,good biocompatibility and biodegrade-ability.It has the common flaws of natural polymers,such as low mechanical properties and poor antimicrobial activity,which severely limit their applications.In this paper,novel biodegradable films(NBF) of KGM with palmitoylated KGM(PKGM) were prepared by using the solventcasting technique.The structure,thermal and mechanical properties of the NBF were investigated.The results suggested that a strong hydrogen bonding was formed in NBF,which resulted in good miscibility between KGM and PKGM.The tensile strength and elongation at break of the NBF were enhanced significantly with the increase of PKGM in a certain range.With the addition of 0.75%PKGM by weight,tensile strength and elongation at break of NBF were improved largely to 117.12 MPa and 14.39%.From this work,we hope to provide one of the promising ways to design new edible food films and coatings materials with good mechanical properties.展开更多
Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium,which is expected to solve the difficulty in separation and the poor selectivity of traditi...Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium,which is expected to solve the difficulty in separation and the poor selectivity of traditional photocatalysts in carbonate-containing uranium wastewater.In this paper,theγ-FeOOH/konjac glucomannan grafted with phenolic hydroxyl groups/poly-N-isopropylacrylamide(γ-FeOOH/KGM(Ga)/PNIPAM)thermosensitive hydrogel is proposed as the photocatalysts for extracting uranium from carbonate-containing uranium wastewater.The dynamic phase transformation is demonstrated to confirm the arbitrary transition ofγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel from a dispersed state with a high specific surface area at low temperatures to a stable aggregated state at high temperatures.Notably,theγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel achieves a remarkably high rate of 92.3%in the removal of uranium from the wastewater containing carbonates and maintains the efficiency of uranium removal from uranium mine wastewater at over 90%.Relying on electron spin resonance and free radical capture experiment,we reveal the adsorption-reduction-nucleation-crystalliza tion mechanism of uranium onγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel.Overall,this strategy provides a promising solution to treating uranium-contaminated wastewater,showing a massive potential in water purification.展开更多
基金Supported by Foundation of Minnan Normal University,the Funding(type A,No.JA11167)from the Fujian Education DepartmentNational Natural Science Foundation of China(31071518 and 31271837)+2 种基金Joint Specialized Research Fund for the Doctoral Program of Higher Education,MOE(20113515110010)Science and Technology Planning Project of technological department(2012GA7200022)Natural Science Foundation of Fujian Province(2011J01285)
文摘Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperature on the extent of amination. And the molecular simulation technology was adopted to analyze the conformation stability of aminate （AKGM）. The results indicate that when the amount of CEA is higher, the extent of amination is higher. The optimum concentration of NaOH, reaction time and temperature are 10% NaOH, 70 ℃ and 45 rain, respectively. IR shows KGM is successfully aminated. The conformation of AKGM is in a random clew-like shape.
文摘Konjac glucomannan(KGM) has been generally used in food,film-former and biomedical applications,especially in the edible packing films due to its excellent film-forming ability,good biocompatibility and biodegrade-ability.It has the common flaws of natural polymers,such as low mechanical properties and poor antimicrobial activity,which severely limit their applications.In this paper,novel biodegradable films(NBF) of KGM with palmitoylated KGM(PKGM) were prepared by using the solventcasting technique.The structure,thermal and mechanical properties of the NBF were investigated.The results suggested that a strong hydrogen bonding was formed in NBF,which resulted in good miscibility between KGM and PKGM.The tensile strength and elongation at break of the NBF were enhanced significantly with the increase of PKGM in a certain range.With the addition of 0.75%PKGM by weight,tensile strength and elongation at break of NBF were improved largely to 117.12 MPa and 14.39%.From this work,we hope to provide one of the promising ways to design new edible food films and coatings materials with good mechanical properties.
基金supported by the National Natural Science Foundation of China(21976147,U2267224,and 22106126)the Sichuan Science and Technology Program(2021YFG0096,2024NSFSC1148,2022YFG0371,and 2024NSFTD0012)+2 种基金the Project of State Key Laboratory of Environmentfriendly Energy Materials in Southwest University of Science and Technology(21fksy22)the Research Fund of Southwest University of Science and Technology for PhD(23zx7103)the Open Fund of China National Nuclear Corporation Key Laboratory for Uranium Extraction from Seawater(KLUES202201).
文摘Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium,which is expected to solve the difficulty in separation and the poor selectivity of traditional photocatalysts in carbonate-containing uranium wastewater.In this paper,theγ-FeOOH/konjac glucomannan grafted with phenolic hydroxyl groups/poly-N-isopropylacrylamide(γ-FeOOH/KGM(Ga)/PNIPAM)thermosensitive hydrogel is proposed as the photocatalysts for extracting uranium from carbonate-containing uranium wastewater.The dynamic phase transformation is demonstrated to confirm the arbitrary transition ofγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel from a dispersed state with a high specific surface area at low temperatures to a stable aggregated state at high temperatures.Notably,theγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel achieves a remarkably high rate of 92.3%in the removal of uranium from the wastewater containing carbonates and maintains the efficiency of uranium removal from uranium mine wastewater at over 90%.Relying on electron spin resonance and free radical capture experiment,we reveal the adsorption-reduction-nucleation-crystalliza tion mechanism of uranium onγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel.Overall,this strategy provides a promising solution to treating uranium-contaminated wastewater,showing a massive potential in water purification.
