عنوان

Thermodynamics of amino acids in aqueous electrolyte solutions

شماره

TLpq304404067

زبان متن نوشتاري يا گفتاري و مانند آن

انگلیسی

عنوان اصلي

Thermodynamics of amino acids in aqueous electrolyte solutions

نام عام مواد

[Thesis]

نام نخستين پديدآور

M. K. Khoshkbarchi

نام ساير پديدآوران

J. H. Vera

نام ناشر، پخش کننده و غيره

McGill University (Canada)

تاریخ نشرو بخش و غیره

1997

نام خاص و کميت اثر

199

جزئيات پايان نامه و نوع درجه آن

Ph.D.

کسي که مدرک را اعطا کرده

McGill University (Canada)

امتياز متن

1997

متن يادداشت

A novel method has been developed for the measurement of the activity coefficients of an amino acid and the mean ionic activity coefficients of an electrolyte in water-electrolyte-amino acid systems. The method uses an electrochemical cell with two ion selective electrodes and a reference electrode. Activity coefficient data, at 298.15 K, for eight water-electrolyte-amino acid systems were measured. The cell consisted of a cation and an anion ion selective electrode, and the potential of each was measured versus a double junction reference electrode. The amino acids studied were glycine, DL-alanine, DL-valine and DL-serine and the electrolytes studied were NaCl and KCl. For the same systems, the solubilities at 298.15 K of the amino acids were measured at various electrolyte concentrations. The results show that the activity coefficients and the solubility of the amino acid in aqueous electrolyte solutions are strongly affected by the concentrations of both the electrolyte and the amino acid, the chemical structure of the amino acid and the nature of the cation of the electrolyte. The activity coefficients of amino acids in aqueous electrolyte solutions were modelled using a two-parameter excess Gibbs free energy model based on the contribution of a long range interaction term represented by the Bromley or the K-V model and a short range interaction term represented by the NRTL or the Wilson model. A model based on the perturbation of a hard sphere reference system, coupled with a mean spherical approximation model, was also developed to correlate the activity coefficient of the amino acid and the mean ionic activity coefficient of the electrolyte in water-electrolyte-amino acid systems. The model can also predict the activity coefficients of amino acids in aqueous electrolyte solutions, without adjusting any parameter, at low electrolyte concentrations and slightly deviates from the experimental data at higher electrolyte concentrations. A model was developed to correlate the solubilities of amino acids in aqueous and aqueous electrolyte solutions. The activity coefficients of amino acids in both aqueous and aqueous electrolyte solutions were represented by the perturbed mean spherical approximation model. It was shown that upon availability of independently evaluated experimental data for usd\Delta\ husd and usd\Delta\ gusd, the water-amino acid solubility model can accurately predict the solubility of amino acids in aqueous solutions without any adjustable parameter.

موضوع مستند نشده

Amino acids

موضوع مستند نشده

Applied sciences

موضوع مستند نشده

Aqueous electrolyte solutions

موضوع مستند نشده

Chemical engineering

موضوع مستند نشده

Thermodynamics

مستند نام اشخاص تاييد نشده

J. H. Vera

مستند نام اشخاص تاييد نشده

M. K. Khoshkbarchi

نام الکترونيکي

فرمت انتشار

p

نوع ماده

[Thesis]

کد کاربرگه

276903

سطح دسترسي

a

تكميل شده

Y