Three types of electrodeposition,DC electrodeposition,low-frequency pulsed electrodeposition and high-frequency pulsed electrodeposition,were used to deposit cuprous oxide on the concrete surface to improve the antiba...Three types of electrodeposition,DC electrodeposition,low-frequency pulsed electrodeposition and high-frequency pulsed electrodeposition,were used to deposit cuprous oxide on the concrete surface to improve the antibacterial properties of concrete.The effects of pulse deposition frequency on the antibacterial property of concrete were studied using sulfate-reducing bacteria(SRB)and Escherichia coli(E.coli)as model bacteria.The bacterial concentration and the antibacterial rate were measured to evaluate the antibacterial performance of concrete.The effects of different deposition methods on the elemental content of copper and the amount of copper ions exuded were studied.XRD and SEM were used to analyze the microstructure of the deposited layers.The experimental results show that the concrete treated by electrodeposition exhibited good antibacterial properties against SRB and E.coli.The antibacterial effect of cuprous oxide deposited on concrete by pulse method was better than that by direct current(DC)method.The antibacterial rate of concrete was positively correlated with the exudation rate of copper ion.As the pulse frequency increased,the deposits content on the surface was increased with an accompanying improvement in the antibacterial property.Besides,the pulsed current had an indiscernible effect on the composition of the sediments,which were all mainly composed of Cu_(2)O,but the morphology of the Cu_(2)O differed greatly.Cubic octahedral cuprous oxide had better antibacterial properties with the highest copper ion leaching rate compared with cubic and spherical cuprous oxide.展开更多
自新冠疫情爆发以来,废弃一次性医用口罩(disposable medical masks,DMMs)处理问题日益严峻,通过制备DMMs纤维增强砂浆,不仅可以大量回收利用一次性医用口罩,还可以提高砂浆的抗裂性能。研究了DMMs纤维长度、掺量对砂浆的力学性能、干...自新冠疫情爆发以来,废弃一次性医用口罩(disposable medical masks,DMMs)处理问题日益严峻,通过制备DMMs纤维增强砂浆,不仅可以大量回收利用一次性医用口罩,还可以提高砂浆的抗裂性能。研究了DMMs纤维长度、掺量对砂浆的力学性能、干燥收缩以及早期抗裂性能的影响,验证其应用于建筑材料的可行性。结果表明:DMMs纤维的掺入会略微降低砂浆的抗压强度;DMMs纤维长度增加会降低砂浆抗折强度的提升效果;砂浆的后期抗折强度随着DMMs纤维掺量增加呈现先升高后下降的趋势,DMMs纤维长度为15 mm、掺量为1.00%时,28 d抗折强度提升最高,相比基准砂浆提高了19.39%;而随着掺量增加,砂浆的干缩率持续下降,抗裂性能逐渐提高,DMMs纤维掺量为1.25%时,砂浆表面24 h内无裂缝出现。展开更多
基金National Natural Science Foundation of China(Nos.52079048 and 52178203)the Natural Science Foundation of Jiangsu Province(BK20221503)+1 种基金the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical EngineeringInstitute of Rock and Soil Mechanics,Chinese Academy of Sciences(Z020012)。
文摘Three types of electrodeposition,DC electrodeposition,low-frequency pulsed electrodeposition and high-frequency pulsed electrodeposition,were used to deposit cuprous oxide on the concrete surface to improve the antibacterial properties of concrete.The effects of pulse deposition frequency on the antibacterial property of concrete were studied using sulfate-reducing bacteria(SRB)and Escherichia coli(E.coli)as model bacteria.The bacterial concentration and the antibacterial rate were measured to evaluate the antibacterial performance of concrete.The effects of different deposition methods on the elemental content of copper and the amount of copper ions exuded were studied.XRD and SEM were used to analyze the microstructure of the deposited layers.The experimental results show that the concrete treated by electrodeposition exhibited good antibacterial properties against SRB and E.coli.The antibacterial effect of cuprous oxide deposited on concrete by pulse method was better than that by direct current(DC)method.The antibacterial rate of concrete was positively correlated with the exudation rate of copper ion.As the pulse frequency increased,the deposits content on the surface was increased with an accompanying improvement in the antibacterial property.Besides,the pulsed current had an indiscernible effect on the composition of the sediments,which were all mainly composed of Cu_(2)O,but the morphology of the Cu_(2)O differed greatly.Cubic octahedral cuprous oxide had better antibacterial properties with the highest copper ion leaching rate compared with cubic and spherical cuprous oxide.