ABS塑料小件化学镀银及银层氯化的研制

Research and preparation of electroless silver plating on tiny ABS plastic pieces and chloridization of the silver coating

在H2SO4/H2O2混合液中对ABS塑料进行表面粗化,然后进行化学镀银,再用FeCl3溶液氯化镀银层,制备出心电图仪(ECG)用一次性Ag/AgCl电极。研究了活化时间和装载量对化学镀银增重及电阻的影响。采用扫描电镜(SEM)和X射线衍射(XRD)技术分析了镀层的表面形貌和物相组成,分别用四探针法和冷热循环法测试了镀层表面的方块电阻及镀层与基体的结合力。结果表明,粗化处理后的ABS塑料表面粗糙度增大,亲水性增加。适宜的活化时间和化学镀银装载量分别为5 min和80 cm2/L。此条件下制备的化学镀银层均匀致密,与基体的结合力强。氯化前后镀银层的导电性均良好,表面方块电阻分别为30 mΩ/□和53.6 mΩ/□。测得Ag/AgCl心电电极的交流阻抗≤3 kΩ,直流失调电压≤100 mV,内部噪音≤150μV,模拟除颤恢复≤3 kΩ,偏置电流耐受度≤100 mV,符合国家医药行业YY/T 0196–2005标准。

The surface of ABS plastic was roughened in H2SO4/H202 mixture solution, and then deposited with silver by electroless plating method. The electroless silver coating was chloridized in FeCl3 solution to prepare a disposable Ag/AgCl electrode for electrocardiograph （ECG）. The effects of activation time and loading capacity on weight gain and sheet resistance of the electroless silver coating were studied. The surface morphology and phase composition of the silver coating were analyzed by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The sheet resistance of the silver coating and its adhesion to the substrate were determined by four-point probe method and hot-cold cycling test, respectively. It was found that roughening treatment increases the surface roughness and hydrophilicity of ABS plastic. The suitable activation time and loading capacity for electroless silver plating is 5 min and 80 cm2/L, respectively. The silver coating obtained under these conditions is uniform, compact, and well-adhered to the substrate. The silver coating has a sheet resistance of 30 mΩ/□ before chloridization and 53.6 mΩ/D after chloridization, showing good conductivity. The Ag/AgCI ECG electrode has an alternating-current impedance voltage ≤100 mV, internal of ≤3 kΩ, direct-current offset noise ≤150 μV, simulated defibrillation recovery 〈3 kΩ and bias current tolerance ≤100 mV, meeting the requirement of YY/T 0196-2005 standard for pharmaceutical industry in China.