On Halsey's New Multilayer Adsorption Equation

1952 ◽  
Vol 74 (4) ◽  
pp. 1081-1081 ◽  
Author(s):  
W. Keith Hall
2019 ◽  
Vol 67 (2) ◽  
pp. 59-68
Author(s):  
Jerzy K. Garbacz ◽  
Karol Karpiński ◽  
Mariusz Kozakiewicz

Abstract Continuing the discussion on the description of adsorbate-adsorbate association on homogeneous surfaces of solids, an attempt was made to formulate an analytical form of adsorption equation for a multilayer adsorption phase. The validity of Berezin’s and Kiselev’s assumptions concerning the independence of adsorption in further layers from the model of the phenomenon in the first of them was discussed. The fundamental validity of this assumption has been demonstrated, simultaneously ridding it of its arbitrary character. The main aim of the study was to demonstrate the possibility of formulating a description assuming molecule association in the entire adsorption phase (and not only in the first layer). Theoretical considerations are confined to the case of dimerisation in the concentration range thus warranting the approximation characteristic of the Berezin and Kiselev model. The obtained final adsorption equation exhibits physically acceptable boundary properties; with adequate assumptions it amounts to the Brunauer, Emmett and Teller equation, the equation formulated earlier by one of the authors of this paper or the Langmuir equation.


Holzforschung ◽  
2002 ◽  
Vol 56 (1) ◽  
pp. 91-97
Author(s):  
Kei Morisato ◽  
Yutaka Ishimaru ◽  
Hiroyuki Urakami

Summary To understand the swelling phenomenon of wood in liquids,the saturated amount of adsorption of liquids onto wood and the standard free energy changes of the adsorption were determined. The saturated amount of adsorption obtained by regression for several liquids decreased with increasing molecular size of the solvents. The mechanism of wood swelling is discussed systematically taking all the liquids examined in previous experiments into account. Since methanol molecules require more energy for release from cohesive interactions within bulk liquids in the adsorption onto pre-swollen wood,the values of free energy change of adsorption for methanol were lower than the values for acetone,although the relative swelling with methanol was higher. These results suggest that although the cohesive interaction within the bulk liquids reduces adsorptivity,the phenomenon of wood swelling is influenced not only by monolayer adsorption but also by multilayer adsorption. Therefore,the cohesive interaction within the bulk liquids reduces adsorptivity but enhances the condensation which strongly influences the swelling of wood.


2015 ◽  
Vol 345 ◽  
pp. 81-89 ◽  
Author(s):  
Alexandre de O. Jorgetto ◽  
Adrielli C.P. da Silva ◽  
Marcos H.P. Wondracek ◽  
Rafael I.V. Silva ◽  
Edivaldo D. Velini ◽  
...  

2018 ◽  
Vol 7 (3) ◽  
pp. 966
Author(s):  
Kartik Kulkarni ◽  
Varsha Sudheer ◽  
C R Girish

The potential of agricultural waste cashew nut shells as an adsorbent for removing phenol from wastewater is presented in this paper. The adsorbent was treated with 3M sulphuric acid in order to improve the properties. The experimental parameters such as adsorbent dosage, concentration and temperature were optimized with response surface methodology (RSM). The isotherm data were tested with different isotherm models and it obeyed Freundlich Isotherm showing the multilayer adsorption. The kinetic data satisfied pseudo-first order kinetic model. The maximum adsorption capacity was calculated to be 35.08 mg/g proving the capability of cashew nut shells for removing phenol from wastewater.  


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Qing Chen ◽  
Yuanyuan Tian ◽  
Peng Li ◽  
Changhui Yan ◽  
Yu Pang ◽  
...  

Shale gas is an effective gas resource all over the world. The evaluation of pore structure plays a critical role in exploring shale gas efficiently. Nitrogen adsorption experiment is one of the significant approaches to analyze pore size structure of shale. Shale is extremely heterogeneous due to component diversity and structure complexity. Therefore, adsorption isotherms for homogeneous adsorbents and empirical isotherms may not apply to shale. The shape of adsorption-desorption curve indicates that nitrogen adsorption on shale includes monolayer adsorption, multilayer adsorption, and capillary condensation. Usually, Langmuir isotherm is a monolayer adsorption model for ideal interfaces; BET (Brunauer, Emmett, Teller) adsorption isotherm is a multilayer adsorption model based on specific assumptions; Freundlich isotherm is an empirical equation widely applied in liquid phase adsorption. In this study, a new nitrogen adsorption isotherm is applied to simultaneously depict monolayer adsorption, multilayer adsorption, and capillary condensation, which provides more real and accurate representation of nitrogen adsorption on shale. In addition, parameters are discussed in relation to heat of adsorption which is relevant to the shape of the adsorption isotherm curve. The curve fitting results indicate that our new nitrogen adsorption isotherm can appropriately describe the whole process of nitrogen adsorption on shale.


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