基于PVA的湿敏薄膜制备与湿度响应性能研究

Study on the Preparation and Humidity Response Performance of Humidity-Sensitive Films Based on PVA

摘要: 湿度传感器作为环境监测、医疗设备和农业物联网等领域的关键元件，其核心在于敏感材料的湿敏特性。聚乙烯醇(PVA)具有亲水性基团和溶胀性能让其具备成为湿度敏感材料的可行性，然而纯PVA薄膜存在湿度响应性能不够灵敏、电阻响应范围有限等问题，制约其实际应用。本研究通过在PVA中添加氯化锂(LiCl)制备复合薄膜，并测试了其湿敏性能。通过对薄膜在不同温度下的吸湿情况，接触角测试，SEM及FT-IR等测试手段对样品的湿敏性能进行分析。并探究了LiCl的添加对PVA复合薄膜微观结构、湿度响应特性的调控机制。该PVA复合薄膜的湿敏行为研究为开发一种在低湿度环境下具高灵敏度及良好稳定性的湿度传感器材料提供了参考。

Abstract: As a key component of environmental monitoring, medical equipment and agricultural Internet of Things, the performance of humidity sensors fundamentally depends on the humidity response characteristics of sensitive materials. Polyvinyl alcohol (PVA), rich in hydroxyl groups, has excellent hydrophilicity and hygroscopicity, making it an ideal choice for moisture-sensitive materials. However, pure PVA films have problems such as insufficient humidity response sensitivity and limited resistance response range, which restrict their practical application. In this study, the functional modification of PVA was carried out by introducing lithium chloride (LiCl), and the performance of the samples was characterized by means of hygroscopicity test, surface water droplet contact angle test, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The mechanism by which LiCl doping regulates the microstructure and humidity response characteristics of PVA composite films was further explored. Through the study of the moisture absorption behavior of PVA films, theoretical basis and technical support are provided for the development of humidity sensor materials with high sensitivity and good stability in low-humidity environments.