用于铜离子检测的静电纺纤维膜制备及其性能

Preparation and performance of electrospun membrane for Cu(Ⅱ) detection

针对铜离子检测费用高、难以现场检测及检测探针的污染问题,以天然染料紫胶红为铜离子识别单元,聚丙烯腈(PAN)及聚乙烯吡咯烷酮(PVP)为载体,通过静电纺丝法制备紫胶红/PAN/PVP纤维膜。借助旋转黏度计、扫描电子显微镜、接触角测量仪、X射线衍射仪、傅里叶变换红外光谱仪研究了纺丝液中PAN/PVP质量分数及PAN与PVP质量比对纤维膜结构和性能的影响,并考察了纤维膜对铜离子的检测能力。结果表明:当PAN/PVP质量分数为10%时,纺丝液黏度为300.0 mPa·s,紫胶红与PAN/PVP基纤维膜复合效果较好,纤维形貌良好,平均直径为(171.6±1.9) nm;当PAN与PVP质量比为7∶3时,纤维平均直径为(149.7±0.7) nm,紫胶红/PAN/PVP纤维膜的水接触角为64.1°;紫胶红/PAN/PVP纤维膜在干扰离子溶液中的色相值与颜色无明显变化,而在铜离子溶液中色相变化明显,且产生由红到黄的颜色响应,具有良好的抗干扰性;纤维膜在0.03 mmol/L铜离子溶液中能产生由红到黄的颜色响应,随铜离子浓度递增,纤维膜颜色响应增强,满足复杂水体环境中铜离子的可视化现场检测。

Objective Excessive Cu(Ⅱ)content may cause gastrointestinal disorders,liver and kidney damage,and even death.Therefore,the study of convenient Cu(Ⅱ)detection method is significant for maintaining human health.At present,the Cu(Ⅱ)detection is faced with problems of high detection cost,difficult on-site detection and pollution of detection probes.In order to solve the above problems,this study proposed a convenient Cu(Ⅱ)detection material for more intuitively detecting Cu(Ⅱ)content to avoid the inability so as to timely understand the Cu(Ⅱ)content of water that poses potential health risks.Method In this study,the natural dye lac red(Lac)was used as the Cu(Ⅱ)detection probe,and polyacrylonitrile(PAN)and polyvinylpyrrolidone(PVP)were used as the carrier of the detection probe,and the Lac/PAN/PVP fiber membrane was prepared by electrospinning method.By means of rotational viscometer,scanning electron microscope,X-ray diffractometer and infrared spectrometer,the influences of spinning solution mass fraction and blending ratio on the structures and properties of fiber membranes were studied,and the Cu(Ⅱ)detection performance of fiber membrane was investigated.Results When the mass fraction of PAN/PVP in spinning solution was increased from 7%to 19%,the corresponding viscosity was changed from 52.5 mPa·s to 4316.7 mPa·s.When the mass fraction of PAN/PVP in the spinning solution was 7%,a lot of beads appeared on the surface of the fiber,and the fiber diameter was(102.3±1.8)nm.As the mass fraction of PAN/PVP in spinning solution was increased to 19%,the fiber formation tended to be uniform and smooth,and the fiber diameter increases to(546.3±7.4)nm.The fibers can be formed well at different mass ratios of PAN to PVP.The fiber diameter was decreased from(220.7±2.4)nm when the mass ratio of PAN to PVP was 5∶5 to(113.9±1.3)nm when the mass ratio of PAN and PVP was 9∶1.The water contact angle of the fiber membrane was decreased from 102.2°when the mass ratio of PAN to PVP was 10∶0 to 43.0°when the mass ratio of PAN to PVP was 5∶5.The addition of PVP improved the hydrophilicity of Lac/PAN/PVP fiber membrane.The infrared spectra showed that the absorption peak at 1041 cm-1 was enhanced in the Lac/PAN/PVP fiber membrane,caused by the introduction of more hydroxyl groups on the lac red molecule to enhance the stretching of C—O in C—OH.It meant that lac red was successfully mixed into the fiber membrane.Two crystalline structures were found in the Lac/PAN/PVP fiber membrane.The Lac/PAN/PVP fiber membrane had no significant diffraction peaks at 2θof 32°,46°and 56°.It was found that the lac red was fully dissolved and evenly distributed in the fiber membrane by electrospinning.Only Cu(Ⅱ)can change the hue value of Lac/PAN/PVP fiber membrane from 338.0°to 22.3°,accompanied by a color response from red to yellow.It showed that the Lac/PAN/PVP fiber membrane has good anti-interference ability.The Lac/PAN/PVP fiber membrane hue value gradually changed from 349.9°red to 38.1°yellow.0.03 mmol/L Cu(Ⅱ)solution was able to produce an obvious color response of Lac/PAN/PVP fiber membranes,and the color response intensity was increased with the Cu(Ⅱ)concentration from 0.03 mmol/L to 0.09 mmol/L.Conclusion Lac/PAN/PVP fibers with a good morphology and a diameter of(149.7±0.7)nm were produced when the mass fraction of PAN/PVP was 10%and the mass ratio of PAN to PVP was 7∶3.The Lac/PAN/PVP fibers were able to specifically recognize Cu(Ⅱ)in solutions containing a variety of metal ions,producing a clear color response from red to yellow.Lac/PAN/PVP fiber membranes were capable of detecting Cu(Ⅱ)up to 0.03 mmol/L with the naked eye.The use of Lac/PAN/PVP fiber membranes for Cu(Ⅱ)detection enables the visualization of Cu(Ⅱ)detection and improves the convenience of Cu(Ⅱ)detection.Lac/PAN/PVP membranes have the advantages of good interference immunity and low detection limits,thus has potential applications in the field of Cu(Ⅱ)detection.