Gauden Piotr A, Terzyk Artur P, Rychlicki Gerhard, Kowalczyk Piotr, Cwiertnia Magdalena S, Garbacz Jerzy K
Physicochemistry of Carbon Materials Research Group, Department of Chemistry, N. Copernicus University, Gagarina 7, 87-100 Toruń, Poland.
J Colloid Interface Sci. 2004 May 1;273(1):39-63. doi: 10.1016/j.jcis.2003.08.033.
Experimental adsorption isotherms of four adsorbates (N2, Ar, C6H6, and CCl4) as well as adsorption enthalpy (C6H6 and CCl4) measured on two strictly microporous carbons are used to evaluate the porosity of adsorbents (i.e., pore size distributions (PSDs) and average pore diameter ( Lav )). The influence of the diameter of adsorbates ( dA) as well as of the temperature ( T ) is analyzed in order to explain the differences or similarities between the above-mentioned quantities for all systems. Proposed previously, the general relationships between the parameters of the Dubinin-Astakhov (DA) isotherm equation (the characteristic energy of adsorption ( E0 ) and the exponent of this equation ( n )) and the average slit-width of carbon micropores are investigated. Moreover, the thermodynamic verification of the Horvath-Kawazoe (HK) theory and the ND model is presented based on data of the adsorption and enthalpy of adsorption of benzene and carbon tetrachloride on two carbons. Finally, the pore diameters calculated from calorimetry data using the Everett and Powl method and those calculated applying the recently developed equations are compared. In our opinion the change of apparent PSD should be monitored by performing a series of isotherm measurements from high (equal and higher than room temperature) to low temperatures (ca. 77.5 K) as was presented in the current study. Moreover, the analysis of the experimental data leads to the conclusion that the entropy of C6H6 and CCl4 can approach to the values characteristic of quasi-solid (a partially ordered structure). Therefore, this behavior of the adsorbate should be taken into consideration in the theoretical assumptions of model and its thermodynamic verification.
在两种严格意义上的微孔碳上测量的四种吸附质（N₂、Ar、C₆H₆和CCl₄）的实验吸附等温线以及吸附焓（C₆H₆和CCl₄）被用于评估吸附剂的孔隙率（即孔径分布（PSD）和平均孔径（Lav））。分析了吸附质直径（dA）以及温度（T）的影响，以解释所有系统中上述量之间的差异或相似性。如先前提出的，研究了杜宾宁 - 阿斯塔霍夫（DA）等温线方程参数（吸附特征能量（E0）和该方程的指数（n））与碳微孔平均狭缝宽度之间的一般关系。此外，基于苯和四氯化碳在两种碳上的吸附及吸附焓数据，对霍瓦特 - 川添（HK）理论和ND模型进行了热力学验证。最后，比较了使用埃弗雷特和鲍尔方法从量热数据计算得到的孔径与应用最近开发的方程计算得到的孔径。我们认为，如本研究所示，应通过从高温（等于或高于室温）到低温（约77.5 K）进行一系列等温线测量来监测表观PSD的变化。此外，对实验数据的分析得出结论，C₆H₆和CCl₄的熵可以接近准固体（部分有序结构）的特征值。因此，在模型的理论假设及其热力学验证中应考虑吸附质的这种行为。
