Chitosan-functionalized mesoporous silica MCM-41 (Chi/M41) was prepared by a mild method. In the composite materials, the spherical MCM-41 particles were regarded as supporting skeletons, which reduced the effect of chitosan swelling on the repeatability and reliability of quartz crystal microbalance (QCM) sensors at high relative humidity (RH), and chitosan provided good film-forming properties of the final composite. The composite structure effectively improved the sensitivity of the QCM sensors compared to that of chitosan and MCM-41 sensors. The QCM sensor based on the Chi/M41 composites showed excellent sensitivity (58.4 ± 0.3 Hz/% RH). In addition, the optimal sensor exhibited excellent reliability, such as negligible humidity hysteresis (0.8 ± 0.1% RH), a small variation coefficient (1.1 ± 0.1), short response and recovery times (18 s/15 s) and good long-term stability. Furthermore, the Langmuir adsorption isotherm model and the Gibbs free energy were used to investigate the adsorption mechanism of water molecules on the sensitive films in this work.

通过温和的方法制备壳聚糖官能化的介孔二氧化硅MCM-41（Chi / M41）。在复合材料中，球形MCM-41颗粒被视为支撑骨架，从而降低了壳聚糖溶胀对高相对湿度（RH）下石英晶体微天平（QCM）传感器的重复性和可靠性的影响，并且壳聚糖提供了良好的膜最终复合材料的成型性能。与壳聚糖和MCM-41传感器相比，这种复合结构有效地提高了QCM传感器的灵敏度。基于Chi / M41复合材料的QCM传感器具有出色的灵敏度（58.4±0.3 Hz /％RH）。此外，最佳传感器还具有出色的可靠性，例如可忽略的湿度滞后（0.8±0.1％RH），较小的变异系数（1.1±0.1），响应和恢复时间短（18 s / 15 s），长期稳定性好。此外，本文利用Langmuir吸附等温线模型和Gibbs自由能研究了水分子在敏感膜上的吸附机理。