Anomalous transport in molecularly confined spaces (2007)
We develop a novel theory to predict the density dependence of the diffusivity of simple fluids in a molecularly sized nanopore with diffusely reflecting walls, incorporating nearest neighbor...
Thermal degradation of high density polyethylene in a reactive extruder (2007)
The thermal degradation of high density polyethylene was conducted in a reactive extruder at various screw speeds with reaction temperatures of 400 degrees C and 425 degrees C. The residence time of...
Pore accessibility of N-2 and Ar in disordered nanoporous solids: theory and experiment (2007)
Recently (Nguyen and Bhatia, J. Phys. Chem. C 111:2212-2222, 2007) we have proposed a new algorithm utilising cluster analysis principles to determine pore network accessibility of a disordered...
Kumar, AVA, Jobic, H, Bhatia, SK
We report here our investigations using Monte Carlo and molecular dynamics (MD) simulations, as well as quasi-elastic neutron scattering experiments, to study the adsorption and diffusion of H-2 and...
Determination of pore accessibility in disordered nanoporous materials (2007)
We propose a new algorithm based on application of cluster analysis to group adsorbate molecules of a highly dense adsorbed phase in the atomistic structural model of a disordered material into...
Kowalczyk, P, Gauden, PA, Terzyk, AP, Bhatia, SK
Hydrogen in slit-like carbon nanopores at 77 K represents a quantum fluid in strong confinement. We have used path-integral grand canonical Monte Carlo and classical grand canonical Monte Carlo...
Kowalczyk, P, Brualla, L, Zywocinski, A, Bhatia, SK
We investigate possible usage of single-walled carbon nanotubes (SWNTs) as an efficient storage and separation device of hydrogen-methane mixtures at room temperature. The study has been done using...
Air reactivity of petroleum cokes: Role of inaccessible porosity (2007)
Tran, KN, Bhatia, SK, Tomsett, A
This paper presents a detailed study of the air reactivity of petroleum cokes measured at temperatures between 400 and 600 degrees C using a combination of characterization techniques and reactivity...
Gigras, A, Bhatia, SK, Kumar, AVA, Myers, AL
The idea that increasing the enthalpy of adsorption increases the adsorptive capacity of carbon and makes it a better storage material for hydrogen is examined here considering the entire...
Density functional theory for adsorption in carbons is adapted here to incorporate a random distribution of pore wall thickness in the solid, and it is shown that the mean pore wall thickness is...
A modified discrete random pore model allowing for different initial surface reactivity (2000)
We investigate here a modification of the discrete random pore model [Bhatia SK, Vartak BJ, Carbon 1996;34:1383], by including an additional rate constant which takes into account the different...
Isotherm hysteresis and pore-blocking effects of trapped molecules on adsorption dynamics is studied here, using the iodine-carbon system in the 300-343 K temperature range. It is found that a...
Characterization of pore size distributions of mesoporous materials from adsorption isotherms (2000)
In this article, a new hybrid model for estimating the pore size distribution of micro- and mesoporous materials is developed, and tested with the adsorption data of nitrogen, oxygen, and argon on...
Investigation of network connectivity in activated carbons by liquid phase adsorption (2000)
The connectivity of the pore network is an important aspect of the structure of porous materials. In this paper we propose a simple percolation theory based method for the determination of pore...
Adsorption hysteresis and criticality in regular mesoporous materials (2000)
In the present work, various theories predicting the critical diameter for the absence of capillary condensation and hysteresis are applied to experimental adsorption isotherms of vapors on regular...
Comprehensive structural characterization of MCM-41: From mesopores to particles (2000)
Sonwane, CG, McLennan, AD, Bhatia, SK
In the present work the meso- and macro-structural characteristics of the mesoporous adsorbent MCM-41 have been estimated with the help of various techniques. The structure is found to comprise four...
A modified discrete random pore model allowing for different initial surface reactivity (2000)
We investigate here a modification of the discrete random pore model [Bhatia SK, Vartak BJ, Carbon 1996;34:1383], by including an additional rate constant which takes into account the different...
Investigation of Network Connectivity in Activated Carbons by Liquid Phase Adsorption (2000)
The connectivity of the pore network is an important aspect of the structure of porous materials. In this paper we propose a simple percolation theory based method for the determination of pore...
Isotherm hysteresis and pore-blocking effects of trapped molecules on adsorption dynamics is studied here, using the iodine-carbon system in the 300-343 K temperature range. It is found that a...
Structural characterization of MCM-41 over a wide range of length scales (1999)
In the present work the meso- and macrostructural characteristics of the recently developed model mesoporous adsorbent MCM-41, of different pore diameters, prepared in our laboratory, have been...
Characterization of surface roughness of MCM-41 using methods of fractal analysis (1999)
Calos, NJ, Bhatia, SK, Sonwane, CG
We report here the characterization of surface roughness of the model mesoporous molecular sieve MCM-41, at various scales of resolution. This material comprises several levels of structure-that of...
A piecewise uniform fitted mesh method turns out to be sufficient for the solution of a surprisingly wide variety of singularly perturbed problems involving steep gradients. The technique is applied...
Analysis of criticality and isotherm reversibility in regular mesoporous materials (1999)
The reversibility of the adsorption isotherms of various gases has been studied on MCM-41 materials of various diameters, and their mixtures have been prepared by mechanical mixing in 1:1 weight...
A piecewise uniform fitted mesh method turns out to be sufficient for the solution of a surprisingly wide variety of singularly perturbed problems involving steep gradients. The technique is applied...
Structural characterization of MCM-41 over a wide range of length scales (1999)
In the present work the meso- and macrostructural characteristics of the recently developed model mesoporous adsorbent MCM-41, of different pore diameters, prepared in our laboratory, have been...
Characterization of surface roughness of MCM-41 using methods of fractal analysis (1999)
Sonwane, CG, Bhatia, SK, Calos, NJ
We report here the characterization of surface roughness of the model mesoporous molecular sieve MCM-41, at various scales of resolution. This material comprises several levels of structure-that of...
Analysis of criticality and isotherm reversibility in regular mesoporous materials (1999)
The reversibility of the adsorption isotherms of various gases has been studied on MCM-41 materials of various diameters, and their mixtures have been prepared by mechanical mixing in 1:1 weight...
Capillary coexistence and criticality in mesopores: Modification of the Kelvin theory (1998)
The classical model of capillary equilibrium in cylindrical pores is modified here by the introduction of molecular concepts and the solid fluid interaction potential. The new approach accurately...
Sonwane, CG, Bhatia, SK, Calos, N
MCM-41 materials of six different pore diameters were prepared and characterized using X-ray diffraction, transmission electron microscopy, helium pycnometry, small-angle neutron scattering, and gas...
Solution of adsorption problems involving steep moving profiles (1998)
The moving finite element collocation method proposed by Kill et al. (1995) Chem. Engng Sci. 51 (4), 2793-2799 for solution of problems with steep gradients is further developed to solve transient...
Determination of pore size distributions by regularization and finite element collocation (1998)
The problem of extracting pore size distributions from characterization data is solved here with particular reference to adsorption. The technique developed is based on a finite element collocation...
Adsorption of binary hydrocarbon mixtures involving methane in carbon slit pores is theoretically studied here from the viewpoints of separation and of the effect of impurities on methane storage. It...
Reactivity of chars and carbons: New insights through molecular modeling (1998)
A new model proposed for the gasification of chars and carbons incorporates features of the turbostratic nanoscale structure that exists in such materials. The model also considers the effect of...
The hydrogenation of cyclohexene over palladium supported in a microporous gamma-alumina pellet is studied thermogravimetrically with a view to measuring the extent of partial internal wetting...
Transport in bidisperse adsorbents: Significance of the macroscopic adsorbate flux (1997)
Transport in bidisperse adsorbents is investigated here, while incorporating a two-dimensional model for adsorbate diffusion in the microparticles. The latter treatment permits consideration of the...
Capillary network models for transport in packed beds: Considerations of pore aspect ratio (1996)
The conventional analysis for the estimation of the tortuosity factor for transport in porous media is modified here to account for the effect of pore aspect ratio. Structural models of the porous...