改性环氧树脂纳米复合涂层的制备及其阻垢性能测试

Preparation of Modified Epoxy Resin Nanocomposite Coating and Its Scale Inhibition Performance Test

摘要:

为解决热蒸发法处理高浓工业废水时换热器管路结垢问题，对金属换热表面环氧树脂（ER）防腐涂层进行改性，提升其在高温、高盐废水中的阻垢性能，从而提升换热器换热效率，延长使用寿命。采用氟硅烷（SFT）与聚偏二氟乙 烯（PVDF）修饰ER?SiO₂涂层，制备得到超疏水ZnO/ER?0.7%SiO₂?SFT?0.7%PVDF涂层（双氟改性涂层），然后使用配制溶液对纯铝基材和铝基双氟改性涂层分别进行耐垢性能测试与机理分析，探究盐度、流速与温度对于涂层结垢性能的影响。结果表明，双氟改性后，涂层的水接触角从（149.8 ± 0.5）°增加到（154.3 ± 0.5）°，乙二醇接触角从 （77.4 ± 1.5）°显著增加至（148.8 ± 1.8）°。在盐度不高于4%、温度80 ℃以及低流速条件下，涂层阻垢率分别维持在70%、76%~77%和78%。

Abstract:

To address heat exchanger fouling during the treatment of highly concentrated industrial wastewater via thermal evaporation， this paper modifies the epoxy resin （ER） anticorrosive coating on metal heat exchanger surfaces to improve scale inhibition performance in high-temperature and high-salinity conditions， thereby enhancing heat transfer efficiency and prolonging service life. The ER-SiO₂ coating was further modified with fluorosilane （SFT） and polyvinylidene difluoride （PVDF）， producing a superhydrophobic ZnO/ER-0.7%SiO₂-SFT-0.7%PVDF coating （bi-fluorine modified coating）. The fouling resistance tests were conducted on pure aluminum substrate and the aluminum-based bi-fluorine modified coating， and the scale inhibition mechanism was analyzed. The effects of salinity， flow rate， and temperature on coating performance were investigated. The results show that after bi-fluorine modification， the water contact angle increases from （149.8 ± 0.5）° to （154.3 ± 0.5）° and the glycol contact angle increases significantly from （77.4 ± 1.5）° to （148.8 ± 1.8）°. The coatings maintain scale inhibition rates of 70%， 76%-77%， and 78% under salinities up to 4%， temperatures up to 80 °C， and low flow rates， respectively.