Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delig...Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delignified sapwood(DSW),delignified heartwood(DHW)and lignocellulose(LC)samples at different temperatures.Results indicate that below the freezing point of bulk water,free water freezes,causing its signal to disappear from the distribution.Then,the low temperature distributions of the unfrozen bound water contain more information about its components,with DSW,DHW and LC containing two distinct states of bound water(OH bound water(B-water)and more freely bound water(C-water)).Furthermore,it was observed that within the temperature range of−3°C to−60°C,B-water in DSW,DHW and LC maintained a higher unfrozen water content(UWC)value than C-water,and the T_(1)/T_(2)ratios for B-water were consistently higher than that for C-water,indicating that B-water has a greater antifreeze capacity.T_(2)and T_(1)distributions offer different kinds of information about water components,and all peaks within the distribution have been assigned.展开更多
MXenes,an extensive family of two-dimensional(2D)materials,have attracted significant attention across diverse fields owing to their exceptional biological,optoelectronic,mechanical,and chemical properties,enabling th...MXenes,an extensive family of two-dimensional(2D)materials,have attracted significant attention across diverse fields owing to their exceptional biological,optoelectronic,mechanical,and chemical properties,enabling their application in numerous fields.Among these,photothermal water evaporation(PWE)has emerged as a particularly promising approach in wastewater treatment,driven by the escalating demand for fresh and pure water.Despite the development of various evaporators to address water scarcity,challenges such as low evaporation efficiency and limited scalability hinder their practical implementation.Over the past decade,MXenes have gained substantial interest owing to their unique elemental composition,porous structure,and surface terminations,which result in remarkable physical and chemical properties that depend on their synthesis methods.However,a key challenge in leveraging MXenes lies in their inherent instability,as they are prone to rapid oxidation upon exposure to air.Stabilizing pristine MXenes is,therefore,critical for their long-term application in PWE.This review highlights strategies to enhance the oxidation stability of MXenes through the incorporation of protective materials such as polymers,delignified wood(DW),and carbonaceous compounds,thereby improving their performance in PWE systems.Furthermore,this review delves into the development of MXene-based composite materials,exploring factors and mechanisms pertinent to their role in PWE.This comprehensive analysis provides valuable insights for researchers and practitioners in the field of wastewater treatment.展开更多
基金supported by Natural Science Foundation of Inner Mongolia Autonomous Region of China (2023MS03027)the National Natural Science Foundation of China (31860185 and 31160141)
文摘Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delignified sapwood(DSW),delignified heartwood(DHW)and lignocellulose(LC)samples at different temperatures.Results indicate that below the freezing point of bulk water,free water freezes,causing its signal to disappear from the distribution.Then,the low temperature distributions of the unfrozen bound water contain more information about its components,with DSW,DHW and LC containing two distinct states of bound water(OH bound water(B-water)and more freely bound water(C-water)).Furthermore,it was observed that within the temperature range of−3°C to−60°C,B-water in DSW,DHW and LC maintained a higher unfrozen water content(UWC)value than C-water,and the T_(1)/T_(2)ratios for B-water were consistently higher than that for C-water,indicating that B-water has a greater antifreeze capacity.T_(2)and T_(1)distributions offer different kinds of information about water components,and all peaks within the distribution have been assigned.
基金the National Natural Science Foundation of China(Grant Nos.22478162,22208128)the Natural Science Foundation of Jiangsu Province(Grant No.BK20210775)Jiangsu University Senior Talent Funding(Grant No.4111310025).
文摘MXenes,an extensive family of two-dimensional(2D)materials,have attracted significant attention across diverse fields owing to their exceptional biological,optoelectronic,mechanical,and chemical properties,enabling their application in numerous fields.Among these,photothermal water evaporation(PWE)has emerged as a particularly promising approach in wastewater treatment,driven by the escalating demand for fresh and pure water.Despite the development of various evaporators to address water scarcity,challenges such as low evaporation efficiency and limited scalability hinder their practical implementation.Over the past decade,MXenes have gained substantial interest owing to their unique elemental composition,porous structure,and surface terminations,which result in remarkable physical and chemical properties that depend on their synthesis methods.However,a key challenge in leveraging MXenes lies in their inherent instability,as they are prone to rapid oxidation upon exposure to air.Stabilizing pristine MXenes is,therefore,critical for their long-term application in PWE.This review highlights strategies to enhance the oxidation stability of MXenes through the incorporation of protective materials such as polymers,delignified wood(DW),and carbonaceous compounds,thereby improving their performance in PWE systems.Furthermore,this review delves into the development of MXene-based composite materials,exploring factors and mechanisms pertinent to their role in PWE.This comprehensive analysis provides valuable insights for researchers and practitioners in the field of wastewater treatment.
