The bet method of analysis of gas adsorption data and its relevance to the calculation of surface areas

Dollimore, D.; Spooner, P.; Turner, Andrew

doi:10.1016/0376-4583(76)90024-8

Cited by 175 publications

(72 citation statements)

References 77 publications

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“…The carbon samples from the degradation in nitrogen for both cellulose and starch were analysed to measure their surface area [13,14]. The cellulose and starch were charred in an oven at 350~ under an atmosphere of nitrogen and the resulting char was analysed for its surface area using a simple adsorption apparatus using nitrogen gas at-170~…”

Section: Materials"mentioning

confidence: 99%

Comparative thermal analysis study of two biopolymers, starch and cellulose

Aggarwal

Dollimore

Heon

1997

Journal of Thermal Analysis

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The degradation of cellulose and starch samples in air and nitrogen has been investigated by thermal analysis techniques. The techniques employed were differential thermal analysis, rising temperature and temperature jump thermogravimetry. Rate data were obtained from these experiments and Arrhenius parameters calculated from these values. This data was used to determine the mechanism by which the cellulose and starch samples degraded. The Arrhenius parameters were also calculated. The behavior of starch and cellulose upon thermal analysis were compared and are reported. Eaa for corn starch was found to be 474 kJ mol q and for a cellulose 242 kJ mol q

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Section: Materials"mentioning

confidence: 99%

Comparative thermal analysis study of two biopolymers, starch and cellulose

Aggarwal

Dollimore

Heon

1997

Journal of Thermal Analysis

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“…In the case of surface properties oftheresidues left in the decomposition the character of the surface is usually assessed from its adsorption properties. The adsorption usually studied is nitrogen adsorption at the temperature of liquid boiling nitrogen and the interpretation is in terms of the surface area [5] and the pore size distribution [6]. The other important property which changes in a solid state decomposition is the density.…”

mentioning

confidence: 99%

The use of complementary data in the application of thermal analysis techniques

Dollimore

1978

Journal of Thermal Analysis

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Tha use of thermal analytical procedures to obtain both thermodynamic and kinetic parameters is outlined. The advantage of DTA techniques in establishing thermodynamic data is demonstrated. Kinetic data calculated from TG data is demonstrated~ Kinetic data calculated from TG data leads to plots of the logarithm of the specific reaction rate constant against lIT (where Tis the temperature in degrees Kelvin) and from this point onwards the calculation is the same to establish the kinetic parameters no matter whether the data was obtained from TG or isothermal studies, Information on changes in the density and surface area of solid residues in the decomposition process leads to the conclusion that the number of particles present changes significantly during the decomposition and it is pointed out that this factor is largely ignored in setting up kinetic models for the decomposition of solid materials.Differential thermal analysis (DTA) and Thermogravimetry (TG) can be used to produce thermodynamic or kinetic data when dealing with the decomposition of solid oxysalts [1 ]. To obtain unambiguous interpretations however it is necessary to obtain data on the systems under investigations by as many different techniques as possible [2]. The complementary data that can be best utilised are those associated with surface texture and structure [3]. This is especially true when dealing with kinetic aspects of a reaction [4]. In the case of surface properties oftheresidues left in the decomposition the character of the surface is usually assessed from its adsorption properties. The adsorption usually studied is nitrogen adsorption at the temperature of liquid boiling nitrogen and the interpretation is in terms of the surface area [5] and the pore size distribution [6]. The other important property which changes in a solid state decomposition is the density. This can be combined with the surface area changes to indicate the change in particle size during decomposition [7], The manner by which the density is determined is important as also is the pretreatment received, such as effective outgassing before commencing measurements [8 ]. The investigation of solid's receiving heat treatment is made more important in that many industrial processes the solids involved are subjected to a rising temperature programme which can be simulated on DTA or TG equipment. The ancillary information is of two kinds, first information producing kinetic parameters by an alternative route or which restrict the number of possible kinetic processes and secondly data which adds to the general information regarding the Jr. Thermal Anal. 13, 1978

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“…A forma empírica de uma isoterma de adsorção foi reconhecida em 1926 por Freundlich [35] , e, mais tarde, foi derivada teoricamente a partir da equação de Langmuir [35,36] , com a adoção do mecanismo de Langmuir e a introdução de uma série de hipóteses simplificadoras, os pesquisadores Brunauer, Emmet e Teller desenvolveram o método de BET [9,35,36,37] , para determinar a efetiva área de materiais sólidos que apresentam complicadas formas, tais como os materiais particulados porosos. A superfície de um pó é um fator importante que determina muitas de suas propriedades.…”

Section: Modelo Betunclassified

“…A superfície de um pó é um fator importante que determina muitas de suas propriedades. Existem vários métodos de avaliação desta área, mas a resposta em cada caso depende muito do método e da propriedade utilizada [37] .…”

Section: Modelo Betunclassified

“…A EIE é uma técnica eletroanalítica onde se aplica um potencial de [1] ;  A região da Dupla Camada Elétrica (DCE) é determinada com o intervalo entre os picos de redução e oxidação do eletrólito [1,41-44, 55, 56] ;  Tempo do ensaio depende da velocidade de varredura [1] ;  Em caso de perturbações no ensaio os pontos obtidos serão do potencial de equilíbrio [1,17,21,22] ;  Requer elevada relação superfície/volume do eletrodo poroso [1] ; Impedância  Utilização de sinais muitos pequenos que não perturbam as propriedades do eletrodo [15,[45][46][47] ;  Possibilidade de estudar reações Redox e medir as taxas destas reações em meios de baixa condutividade [15, 45-47, 49, 50] ;  A resistência de polarização e a capacitância da dupla camada podem ser determinadas numa mesma medida [15, 45-47, 49, 50] ;  A cinética eletródica é determinada por outros métodos [15,[45][46][47] ; BET  Determinação acurada da área superficial da amostra, independe da morfologia da partícula [9,10,35,37] ;  Depende da massa da amostra, precisa de um tamanho pré-determinado da amostra [9,10,35,37] ; Oxidação do CO  Permite determinar a área superficial ativa dos eletrodos das CaC [12,13,39,40,48] ;  Este método permite determinar a área superficial dos eletrodos das CaC, mas somente dos eletrocatalisadores metálicos, aplicação esta relacionada com muitas incertezas [12,39,40,48] ;…”

Section: Introductionunclassified

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Uso da voltametria cíclica e da espectroscopia de impedância eletroquímica na determinação da área superficial ativa de eletrodos modificados à base de carbono

Souza¹

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The bet method of analysis of gas adsorption data and its relevance to the calculation of surface areas

Cited by 175 publications

References 77 publications

Comparative thermal analysis study of two biopolymers, starch and cellulose

Comparative thermal analysis study of two biopolymers, starch and cellulose

The use of complementary data in the application of thermal analysis techniques

Uso da voltametria cíclica e da espectroscopia de impedância eletroquímica na determinação da área superficial ativa de eletrodos modificados à base de carbono

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