变色硅胶吸湿及变色特性研究

Research of moisture absorption and color variation properties of allochroic silicagel

目的通过建立变色硅胶吸湿模型和色度值与吸湿量关系的模型,明确变色硅胶颜色变化与环境湿度的关系,进而为基于变色硅胶的湿度指示卡提供理论依据。方法建立变色硅胶在不同湿度和温度下的数学模型,并进行验证实验。结果变色硅胶饱和吸湿量与环境湿度的关系模型为:Q_h=-0.00434RH^2+0.7113RH+2.6664,R^2=0.9933;所用数学模型模型(Q_t=Q_h*[1-exp(--k*t)])和Arrhenius方程拟合所得方程的判定系数R^2都在0.99以上,验证实验的平均相对误差在90%RH和70%RH时分别为1.51%和2.85%;变色硅胶吸湿量与色度值(b值)的线性回归方程为:b=20.488-0.654 Q_t,R^2=0.9799,验证实验的平均相对误差为5.24%,远远低于10%的可接受水平。结论所建模型能够很好地预测变色硅胶的吸湿过程及吸湿后的颜色变化情况,可据此制作基于变色硅胶的湿度指示卡。

Objective To provide theoretical foundation for humidity sensitive indicators based on al-lochroic silicagels by establishing a moisture absorption model and a chromatic value and moisture absorption amount relationship model of allochroic silicagel which could describe the relationship between color varia-tions and environmental humidities. Methods Obtaining and validating the moisture absorption models of allochroic silicagel under different humidities and temperatures. Results The model that described the rela-tionship between saturated moisture amount and relative humidity is: Qh=-0.00434RH2+ 0.7113RH+2.6664, R2=0.9933; Determination coefficient R2 of the mathematical model (Qt=Qh*[1-exp(-k*t)]) and the Arrhenius equation fitting equations were all above 0.99, the average relative errors of validation test under 90%RH and 70%RH were 1.51%and 2.85%, respectively, and the equation of linear regression between chromatic value (b value) and moisture absorption amount was:b=20.488-0.654Qt, R2=0.9799, with a 5.24%average relative error that was far below the acceptable level. Conclusion The established models well forcasted the color varia-tions related to moisture absorption amount of allochroic silicagel, providing a possibility of getting humidity sensitive indicators based on the color variations of allochroic silicagels.