In this study,Mg O was partially used as an alkali source in the peroxide bleaching process of bleached chemi-thermomechanical pulp(BCTMP).The effects of substitution percentage of Mg O for Na OH on the bulk,optical,a...In this study,Mg O was partially used as an alkali source in the peroxide bleaching process of bleached chemi-thermomechanical pulp(BCTMP).The effects of substitution percentage of Mg O for Na OH on the bulk,optical,and physical properties of bleached pulp,and the main effluent characteristics were analyzed.In addition,the influencing mechanism of Mgbased alkali on the strength properties of the BCTMP was further investigated.Strength properties of the BCTMPs were investigated as a function of charge characteristics,fiber morphology,surface lignin content,relative bonding area,and hydrogen bonds of the BCTMP.The results showed that cationic demand(CD) and chemical oxygen demand(COD_(Cr)) of the bleaching effluent decreased as the substitution percentage of Mg O for Na OH increased; meanwhile,the bulk and optical properties of the BCTMP increased.Nevertheless,the strength properties(tensile,tear,and burst indices) of the bleached pulp decreased as the substitution percentage of Mg O for Na OH increased.The decrease in the fiber charge density and increase in the surface lignin content affected the fiber swelling,resulting in a decline in pulp interfibers bonding strength and further loss of the tensile and burst indices.展开更多
Lignocellulosic biomass such as plants and agricultural waste are ideal to tackle the current energy crisis and energy-related environmental issues.Carbon-rich lignin is abundant in lignocellulosic biomass,whose high-...Lignocellulosic biomass such as plants and agricultural waste are ideal to tackle the current energy crisis and energy-related environmental issues.Carbon-rich lignin is abundant in lignocellulosic biomass,whose high-value transformation and utilization has been the most urgent problem to be solved.Herein,we propose a method for the preparation of porous carbon from lignin employing an H_(3)PO_(4)-assisted hydrothermal method.We characterize the as-prepared lignin-derived porous carbon and investigate its potential for energy storage.After assisted hydrothermal treatment followed by carbonization at 800℃,the lignin-derived porous carbon displays a high specific capacitance(223.6 F·g^(–1) at 0.1 A·g^(–1))and excellent cycling ability with good capacitance retention.In this present study,the resultant lignin-derived porous carbon was used as the electrode of a supercapacitor,illustrating yet another potential high-value use for lignin,namely as a candidate for the sustainable fabrication of main supercapacitor components.展开更多
With the rapid development of“Internet of Things”and human-computer interaction techniques,it is essential and urgent to develop facile and scalable fabrication platforms for stretchable flexible sensor.Herein,we re...With the rapid development of“Internet of Things”and human-computer interaction techniques,it is essential and urgent to develop facile and scalable fabrication platforms for stretchable flexible sensor.Herein,we report a facile strategy of using the green choline chloride-acrylamide deep eutectic solvent(CC-AM DES)to guide the in-situ ring-opening polymerization ofα-lipoic acid(LA),leading to the successful development of a stretchable ionogel material.The as-prepared ionogel from CC-AM DES system exhibits multifunctional merits including the super stretchability(>9000%),100%UV-blocking ability,tunable adhesiveness(29-414 kPa),high ionic conductivity(4.45×10^(-4) S/cm),and ideal anti-freezing(-27℃).In addition,this outstanding ionogel can be readily coated on various material substrates with designable shapes and patterns.Owning to these promising properties and performances,a scalable flexible strain sensor is assembled from the ionogel and exhibits stable resistance variations(R/R_(0))towards multiple external mechanical stimulus.This study provides a green,cost effective,and scalable strategy to fabricate ionogel materials and multifunctional flexible strain sensors,showing a great potential in the fast-emerging highly stretchable wearable/flexible electronics.展开更多
Maintaining a constant chemical concentration(Iso-concentration,IC)has been found to be an effective method to improve peroxide bleaching efficiency for chemi-thermomechanical pulp(CTMP).In this study,the mechanism of...Maintaining a constant chemical concentration(Iso-concentration,IC)has been found to be an effective method to improve peroxide bleaching efficiency for chemi-thermomechanical pulp(CTMP).In this study,the mechanism of IC bleaching was investigated.The concentrations of H2O2 and total alkali in IC bleaching were monitored and compared with those in conventional bleaching processes.Control experiments without pulp were carried out to explore the effects of bleaching additives on H2O2 decomposition.The results showed that the concentrations of H2O2 and the total alkali at the early and later stages of IC bleaching were relatively low and high,respectively;thus,undesired decomposition of H2O2 was inhibited,and brightness was improved.Moreover,the stabilizer played an important role in inhibiting the undesired H2O2 decomposition.This may explain why high bleaching efficiency was achieved in IC bleaching.These findings would provide valuable insight for the production of high-brightness bleached chemi-thermomechanical pulp(BCTMP).展开更多
基金financially supported by the Natural Science Foundation of China (31070528)Project of China “Twelfth Five-Year” National Science and Technology Supporting Plan (2011BAC11B04)the Foundation of State Key Laboratory of Pulp and Paper Engineering
文摘In this study,Mg O was partially used as an alkali source in the peroxide bleaching process of bleached chemi-thermomechanical pulp(BCTMP).The effects of substitution percentage of Mg O for Na OH on the bulk,optical,and physical properties of bleached pulp,and the main effluent characteristics were analyzed.In addition,the influencing mechanism of Mgbased alkali on the strength properties of the BCTMP was further investigated.Strength properties of the BCTMPs were investigated as a function of charge characteristics,fiber morphology,surface lignin content,relative bonding area,and hydrogen bonds of the BCTMP.The results showed that cationic demand(CD) and chemical oxygen demand(COD_(Cr)) of the bleaching effluent decreased as the substitution percentage of Mg O for Na OH increased; meanwhile,the bulk and optical properties of the BCTMP increased.Nevertheless,the strength properties(tensile,tear,and burst indices) of the bleached pulp decreased as the substitution percentage of Mg O for Na OH increased.The decrease in the fiber charge density and increase in the surface lignin content affected the fiber swelling,resulting in a decline in pulp interfibers bonding strength and further loss of the tensile and burst indices.
基金The authors wish to express their gratitude for the financial support from the National Science Foundation for Post-doctoral Scientists of China(Grant No.2019M651050)Guangxi Key Laboratory of Clean Pulp&Papermaking and Pollution Control,College of Light Industry and Food Engineering,Guangxi University(Grant No.2019KF32).
文摘Lignocellulosic biomass such as plants and agricultural waste are ideal to tackle the current energy crisis and energy-related environmental issues.Carbon-rich lignin is abundant in lignocellulosic biomass,whose high-value transformation and utilization has been the most urgent problem to be solved.Herein,we propose a method for the preparation of porous carbon from lignin employing an H_(3)PO_(4)-assisted hydrothermal method.We characterize the as-prepared lignin-derived porous carbon and investigate its potential for energy storage.After assisted hydrothermal treatment followed by carbonization at 800℃,the lignin-derived porous carbon displays a high specific capacitance(223.6 F·g^(–1) at 0.1 A·g^(–1))and excellent cycling ability with good capacitance retention.In this present study,the resultant lignin-derived porous carbon was used as the electrode of a supercapacitor,illustrating yet another potential high-value use for lignin,namely as a candidate for the sustainable fabrication of main supercapacitor components.
基金supported by the National Natural Science Foundation of China(32071715)Canada Research Chairs program of the Government of Canada,and National Science Foundation for Post-doctoral Scientists of China(2019M651050).
文摘With the rapid development of“Internet of Things”and human-computer interaction techniques,it is essential and urgent to develop facile and scalable fabrication platforms for stretchable flexible sensor.Herein,we report a facile strategy of using the green choline chloride-acrylamide deep eutectic solvent(CC-AM DES)to guide the in-situ ring-opening polymerization ofα-lipoic acid(LA),leading to the successful development of a stretchable ionogel material.The as-prepared ionogel from CC-AM DES system exhibits multifunctional merits including the super stretchability(>9000%),100%UV-blocking ability,tunable adhesiveness(29-414 kPa),high ionic conductivity(4.45×10^(-4) S/cm),and ideal anti-freezing(-27℃).In addition,this outstanding ionogel can be readily coated on various material substrates with designable shapes and patterns.Owning to these promising properties and performances,a scalable flexible strain sensor is assembled from the ionogel and exhibits stable resistance variations(R/R_(0))towards multiple external mechanical stimulus.This study provides a green,cost effective,and scalable strategy to fabricate ionogel materials and multifunctional flexible strain sensors,showing a great potential in the fast-emerging highly stretchable wearable/flexible electronics.
文摘Maintaining a constant chemical concentration(Iso-concentration,IC)has been found to be an effective method to improve peroxide bleaching efficiency for chemi-thermomechanical pulp(CTMP).In this study,the mechanism of IC bleaching was investigated.The concentrations of H2O2 and total alkali in IC bleaching were monitored and compared with those in conventional bleaching processes.Control experiments without pulp were carried out to explore the effects of bleaching additives on H2O2 decomposition.The results showed that the concentrations of H2O2 and the total alkali at the early and later stages of IC bleaching were relatively low and high,respectively;thus,undesired decomposition of H2O2 was inhibited,and brightness was improved.Moreover,the stabilizer played an important role in inhibiting the undesired H2O2 decomposition.This may explain why high bleaching efficiency was achieved in IC bleaching.These findings would provide valuable insight for the production of high-brightness bleached chemi-thermomechanical pulp(BCTMP).
