Statistical Thermodynamic Model for Surface Tension of Aqueous Organic Acids with Consideration of Partial Dissociation

2016 ◽  
Vol 120 (25) ◽  
pp. 4368-4375 ◽  
Author(s):  
Hallie C. Boyer ◽  
Cari S. Dutcher
Keyword(s):  
Surface Tension ◽  
Organic Acids ◽  
Thermodynamic Model ◽  
Statistical Thermodynamic ◽  
Partial Dissociation

scholarly journals Statistical Thermodynamic Model for Surface Tension of Organic and Inorganic Aqueous Mixtures

2016 ◽  
Vol 121 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Hallie C. Boyer ◽  
Bryan R. Bzdek ◽  
Jonathan P. Reid ◽  
Cari S. Dutcher
Keyword(s):  
Surface Tension ◽  
Thermodynamic Model ◽  
Statistical Thermodynamic ◽  
Aqueous Mixtures

Statistical Thermodynamic Model for Si/Al Ordering in Amorphous Aluminosilicates

2005 ◽  
Vol 17 (11) ◽  
pp. 2976-2986 ◽  
Author(s):  
John L. Provis ◽  
Peter Duxson ◽  
Grant C. Lukey ◽  
Jannie S. J. van Deventer
Keyword(s):  
Thermodynamic Model ◽  
Statistical Thermodynamic

scholarly journals Statistical Thermodynamic Model of Gas Adsorption in a Metal-Organic Framework Harboring a Rotaxane Molecular Shuttle

2019 ◽  
Author(s):  
Jonathan Carney ◽  
David Roundy ◽  
Cory M. Simon
Keyword(s):  
Thermodynamic Model ◽  
Gas Adsorption ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
Statistical Thermodynamic ◽  
Temperature Sensitive ◽  
Adsorption Sites ◽  
Metal Organic ◽  
Dynamic Components ◽  
Molecular Shuttle

Metal-organic frameworks (MOFs) are modular and adjustable nano-porous materials with applications in gas storage, separations, and sensing. Flexible/dynamic components that respond to adsorbed gas can give MOFs unique or enhanced adsorption properties. Here, we explore the adsorption properties that could be imparted to a MOF by a rotaxane molecular shuttle (RMS) in its pores. In an RMS-MOF, a macrocyclic wheel is mechanically interlocked with a strut. The wheel shuttles between stations on the strut that are also gas adsorption sites. We pose and analyze a simple statistical thermodynamic model of gas adsorption in an RMS-MOF that accounts for (i) wheel/gas competition for sites on the strut and (ii) the entropy endowed by the shuttling wheel. We determine how the amount of gas adsorbed, position of the wheel, and energy change upon adsorption depend on temperature, pressure, and the interactions of the gas/wheel with the stations. Our model reveals that, compared to an ordinary Langmuir material, the chemistry of the RMS-MOF can be tuned to render adsorption more or less temperature-sensitive and release more or less heat upon adsorption. The model also uncovers a non-monotonic relationship between temperature and the position of the wheel if gas out-competes the wheel for its preferable station.

The metachors of polyvalent and associated electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1079-1089
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský ◽  
Jana Žilková
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Oxalic Acid ◽  
Organic Acids ◽  
Aqueous Solutions ◽  
Preceding Paper ◽  
Weak Electrolytes ◽  
Direct Proportionality ◽  
Very High

The quantity metachor introduced in the preceding paper was evaluated from the experimental data on surface tension of the aqueous solutions for a set of polyvalent and weak electrolytes. The almost complete concentration independence of the metachor and its direct proportionality to the number of the free charges in a dissociated molecule (observed and theoretically substantiated in the above cited paper for strong 1,1-, 1,2- and 2,1-valent electrolytes) has been verified in the present paper also for electrolytes of the higher valency types. The metachor values of fully dissociated 1,1-, 1,2-, 1,3- and 1,4-valent electrolytes follow a ratio (5 ± 1) : (10 ± 1.5) : 15 : 22 cm3 mol-1. Association of the electrolytes decreases correspondingly the metachor value as one can see on the case of electrolytes with bulky ions (NH4SCN, KCH3COO, Na2S2O3, hexacyanoferrates(II) or with the free acids H2SO4, H2CrO4, H3PO4 etc. A weak, in the investigated concentration range neglibility dissociated oxalic acid, consisting of small hydrated hydrophilic molecules, exhibits metachor values close to zero. Dibasic organic acids with a larger number of hydrophobic CH2 groups reach very high negative metachor values, however, their salts again possess metachor values close to 10 cm3 mol-1 - in accordance with the values found for strong 1,2-valent electrolytes. The metachors of ZnCl2 and CdCl2 decrease sharply from the last mentioned value, with increasing concentration while the metachor value of zinc perchlorate remains unchanged at the level corresponding to the fully dissociated salt. This is in agreement with the well known sequence of tendency of the d10-cations to form complexes with the Cl- and ClO-4 anions. All these facts have verified that the metachor can be, in principle, applied for a diagnostic states of the electrolytes in aqueous solutions.

scholarly journals Surface Tension of Aqueous Solutions of Small-Chain Amino and Organic Acids

2019 ◽  
Vol 64 (12) ◽  
pp. 5049-5056
Author(s):  
Mohsin Ali Raza ◽  
Paul D. Hallett ◽  
Xiangyang Liu ◽  
Maogang He ◽  
Waheed Afzal
Keyword(s):  
Surface Tension ◽  
Organic Acids ◽  
Aqueous Solutions ◽  
Small Chain
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