Complutense University Library

An atomic force microscopy and molecular simulations study of the inhibition of barite growth by phosphonates

Pina Martínez, Carlos Manuel and Putnis, Cristine Veta and Becker, Udo and Biswas, Subir and Carrol, E.C. and Bosbach, Dirk and Putnis, Andrew (2004) An atomic force microscopy and molecular simulations study of the inhibition of barite growth by phosphonates. Surface science, 553 . pp. 61-74. ISSN 0039-6028

[img] PDF
411kB

Official URL: http://www.elsevier.com/locate/susc

View download statistics for this eprint

==>>> Export to other formats

Abstract

The effect of five phosphonic acids (hydroxyethylene diphosphonic acid, HEDP; nitro trimethyl phosphonic acid,
NTMP; methylene diphosphonic acid, MDP; amino methylene phosphonic acid, AMP; and sodium phosphonobutane
tricarboxylic acid, PBTC) on the growth of the barite(0 0 1) face has been investigated using atomic force microscopy
(AFM). Experimental data have been obtained by in situ measurements of the velocities of barite monomolecular steps
growing from solutions with different concentrations of each phosphonic acid. Adsorption isotherms, constructed by
plotting individual monomolecular step rates versus inhibitor concentrations, indicate a Langmuir adsorption mechanism
in the range of concentrations from 0.5 to 10 lmol/l. Both affinity constants calculated from adsorption isotherms
and measurements of growth rates of barite monomolecular steps as a function of inhibitor concentration
allowed us to give the following ranking of inhibitor effectiveness: PBTC>NTMP>MDP>HEDPAMP. Molecular
simulations of the interaction of the phosphonic acids with barite(0 0 1) surfaces indicate that only kink sites along
monomolecular steps can be considered as possible inhibition sites. This is in agreement with the AFM observations
and measurements.

Item Type:Article
Uncontrolled Keywords:Adsorption isotherms; Atomic force microscopy; Computer simulations; Growth; Crystallization
Subjects:Sciences > Geology > Mineralogy
ID Code:14003
Deposited On:02 Dec 2011 12:36
Last Modified:02 Dec 2011 12:36

Repository Staff Only: item control page