室内空气质量（Indoor air quality，简称IAQ）的低劣不仅严重影响人类的舒适和健康，同时对工作效率也有着明显的影响。由于人造板的广泛使用，使得甲醛等具有挥发特性的有机化合物（Volatile organic compounds, 简称VOCs）成为室内空气的主要污染物。要改善室内空气质量，需研究建材中VOCs的散发特性从而较为准确地估测其散发速率并进行有效地控制。初始可散发浓度Cm,0、扩散系数Dm和分配系数K是三个描述建材散发特性的关键参数。已有研究主要集中于如何快速、准确测得这三个特性参数方面，鲜有涉及可散发浓度影响机理方面的研究。针对上述问题，本论文开展了相关研究，主要学术贡献如下：首先，提出了一种新的测定建材中VOCs三大散发特性参数的方法——直流舱C-history方法，该方法实验装置简单、测试结果精度较高、测试时间短（不超过12小时）、通用性强（可以用常规测试设备如GC/MS和HPLC进行分析），更适合于工程应用，为建材散发特性的快速测试提供了可靠的技术手段。其次，实验研究了10种建材萃取法得到的总含量和直流舱C-history方法得到的初始可散发浓度Cm,0的差异，研究了温度范围为25oC~80oC时三个散发特性参数随温度的影响机理，发现了温度50oC以上与50oC以下时特性参数随温度的不同变化规律。从微观角度用统计物理理论诠释了初始可散发浓度Cm,0随温度变化的物理机制，解释了萃取法得到的总含量与初始可散发浓度存在差异的原因，导出了Cm,0随温度的变化公式。第三，首次实验研究了相对湿度对建材VOCs初始可散发浓度Cm,0的影响，定性解释了甲醛的Cm,0随湿度升高而增加的原因，并获得了相对湿度范围为20%~85%时和Cm,0及分配系数K与相对湿度之间的经验关系式。最后，综合分析了温度及湿度对散发速率的影响规律，可方便地将建材在环境舱中的测量结果推广至实际使用情况，为室内建材污染物限量标准的改进以及建材的预处理提供了一定的理论依据。
The indoor pollution caused by formaldehyde emitted from building materials, as well as other volatile organic compounds (VOCs) poses an adverse effect on people’s health. Three characteristic parameters, i.e., the initial emittable concentration (Cm,0), the diffusion coefficient (Dm) and the material/air partition coefficient (K), are found to be successful for describing the formaldehyde and VOCs emissions from building materials. Therefore, it is necessary to do some research on the 3 parameters in order to predict and control the emission of VOCs. For the previous researches, there are some weakpoints: (1) the former measurement method of the three characteristic parameters has some defects. For example, complicated system, long test time or poor universal applications; (2) it should be noted that these three characteristic parameters are not only dependent on the physical and chemical properties of the material-pollutant combinations, but also related with the environmental conditions. However, there are little researches on these impact factors; (3) the former studies focused on experiments and models which are all macroeconomic researches. It lacks of microcosmic cognition of the VOCs emission. For the above mentioned problems, the main contributions to academic of this doctoral thesis are shown below:First of the paper, a ventilated C-history method is proposed to measure the 3 characteristic parameters. The test time is very short (less than 12h). It avoids mass loss of the static chamber C-history method and can use universal instruments such as HPLC and GC/MS to detect the VOCs concentration. It is provides technical tools to predict the esmission of VOCs from building materials and is very convenient for engineering application.Secondly, this paper presents a novel insight to understand the change tendency of the initial emittable concentration with temperature, and derives a theoretical correlation to describe the relationship between the emittable percentage (ratio of emittable concentration to total concentration) and temperature by applying the statistical physics theory. The effectiveness of the correlation is validated, which will be very helpful for the scaling of experimental results. Meanwhile, it is discovered that the variation tendency of diffusion coefficient and partition coefficient with temperature above 50oC is very different from that below 50oC. This part will be helpful for predicting the emission characteristics of pollutants under temperature changing conditions and for evaluating the exposure level of people in indoor environment.Thirdly, the impact of relative humidity on the initial emittable concentraton is studied for the first time. The diffusion and partition coefficient effects of relative humidity are also discussed. According to timbering empirical formula that describe relative humudity impact on the characteristic parameters，the character of emission under other humidity can be predicted. Finally, based on the above，correlations between the emission rate and circumstance conditions (temperature and raletive humidity) are derived based on formaldehyde emission from building materials. It is more convenient for engineering application to predict the emission characters under different conditions.
