氧化锌/儿茶酚甲醛树脂微球抗菌粘胶纤维的制备及其性能

Fabrication and properties of antibacterial viscose fibers containing zinc oxide/catechol-derived resin microspheres

为制备高效抗菌和力学性能优良的粘胶纤维,由一步水热反应制备氧化锌/儿茶酚甲醛树脂(ZnO/CFR)微球,将之以不同比例与粘胶纺丝液共混,通过湿法纺丝制得一系列抗菌粘胶纤维。借助扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪、多重光散射仪等研究了ZnO/CFR微球的微观形貌、化学组成及其在粘胶纺丝液中的分散性和稳定性,分析了粘胶纤维的颜色、形态、抗菌性能及力学性能等。结果表明:ZnO/CFR微球形状规则,粒径为0.9~2.5μm,微球内随机分布有若干纳米ZnO,可在粘胶纺丝液中分散均匀,长期保持稳定,纺丝过程中无明显损失;所得抗菌粘胶纤维呈棕黑色,锌含量达0.85~2.08 mg/g,对大肠杆菌和金黄色葡萄球菌具有高效的非溶出型广谱抗菌作用,抑菌率达99.9%以上,且力学性能保持优良。

Objective Viscose fibers are highly regarded for their wearing comfort,making them popularly utilized in many fields.Equally,they can provide favorable conditions for microbial growth,thereby posing a risk to both material performance and human health.ZnO nanoparticles exhibit advantages in broad-spectrum antibacterial activity and low toxicity to the human patient,and thus have been considered one of the most promising candidates.Method Using catechol,ZnCl_(2),and formaldehyde as precursors,ZnO nanoparticles/catechol-formaldehyde resins microspheres(denoted as ZnO/CFR)were synthesized via a one-pot hydrothermal method.ZnO/CFR were then used as additives to fabricate antimicrobial viscose fibers through wet-spinning technologies.Micro morphologies and chemical structures of ZnO/CFR were investigated.Dispersibility and stability of ZnO/CFR in the spinning solution were monitored.Antibacterial properties against E.coli and S.aureus of the fiber were evaluated by the zone of inhibition test and shake-flask methods.Zinc contents with the fibers were determined.Color and mechanical performance of the fibers were also investigated.Results ZnO/CFR exhibited a smooth surface with a particle size of 0.9-2.5μm,while some ZnO nanoparticles was irregularly distributed within the microsphere.Zn2p signals appeared in the XPS full spectrum of ZnO/CFR with an atomic content of 1.4%,which was composed of two strong peaks of Zn3p_(1/2) and Zn2p_(3/2) with the binding energy of 1044.8 and 1021.6 eV.ZnO/CFR were evenly dispersed in viscose spinning solutions to achieve homogeneous dispersions.With 0.2,0.4,and 0.6% additions of ZnO/CFR,all the spinning solutions(VF-2%,VF-4%,and VF-6%)showed constantΔT values around 0 throughout 24 h at different heights.All the fibers(VF-2%,VF-4%,and VF-6%)showed a regular shape and uniform brown color,while the color of fibers gradually became darker with the increasing additions of ZnO/CFR.All the fibers showed smooth surfaces without any micro-scale particles,where ZnO/CFR were buried in the fibers rather than exposing on the surface.After the zone of inhibition test,no microbial colony was found to grow in the area in contact with the fiber,while no inhibition zone appeared around the edge of the sample.All the agar plates corresponding to unmodified viscose fibers had some microbial growth,while those corresponding to VF-2%,VF-4%,and VF-6% showed fewer microbial colonies.VF-6%,with 2.08% of zinc in the fiber,achieved a high antibacterial rate of 99.9%against both E.coli and S.aureus.The L*value of VF-2%,VF-4%,and VF-6% decreased to 56.3,49.2,and 39.2 from 91.3 of the control sample while the K/S value increased to 3.9,5.1,and 10.7 from 0.7 of the reference fiber.VF-2%,VF-4%,and VF-6% each showed a slight decrease in breaking tenacity to 11.8,11.6,and 11.4 cN/tex from 12.8 cN/tex of the unmodified fiber.VF-2%,VF-4%,and VF-6%respectively had a breaking elongation rate of 17.8%,17.3%,and 17.1% while that of VF was 19.9%.Conclusion ZnO/CFR prepared were monodisperse microspheres with some ZnO nanoparticles within the microsphere.ZnO/CFR microspheres were uniformly dispersed in the viscose spinning solution and showed long-term stability without any sedimentation of the particles.VF-2%,VF-4%,and VF-6% all showed smooth surfaces where most of ZnO/CFR were buried in the fiber.ZnO/CFR modified fibers exhibited the non-dissolution antibacterial behaviors.With 0.6% additions of ZnO/CFR,VF-6% presented a high antibacterial rate of 99.9% against both E.coli and S.aureus.ZnO/CFR blackened viscose fibers while slightly influencing the mechanical performance of the fiber.This work widens the window of ZnO nanoparticles for the production of antibacterial viscose fibers through wet spinning methods and presents a versatile approach for preparing antibacterial cellulosic materials such as films,foams,and hydrogels.