Heats of mixing and dielectric constants of some partially miscible liquid pairs

1969 ◽  
Vol 47 (4) ◽  
pp. 619-623 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark
Keyword(s):  
Experimental Data ◽  
Hydrogen Bonding ◽  
Acetic Anhydride ◽  
Carbon Disulfide ◽  
Dielectric Constants ◽  
Solution Temperature ◽  
Negative Deviation ◽  
Critical Solution Temperature ◽  
Heats Of Mixing ◽  
Partially Miscible

The physical properties mentioned in the title have been determined for the six systems: (a) aniline–hexane, (b) methanol–cyclohexane, (c) methanol–carbon disulfide, (d) acetic anhydride–carbon disulfide, (e) acetic anhydride–cyclohexane, and (f) triethylamine–water, over the complete range of composition. All six systems are partially miscible, above or below a critical solution temperature (c.s.t.).From the experimental data, the partial molal heats of mixing have been calculated, using the Redlich and Kister equations. The enthalpy of hydrogen bonding in the triethylamine–water compound appears to be about −1.33 kcal per hydrogen bond.The orientation polarization, according to the Syrkin formula, appears always to exhibit negative deviation from ideality, at least over part of the concentration range.

Properties relating to critical phenomena in the acetic anhydride – acetone – carbon disulfide system

1970 ◽  
Vol 48 (6) ◽  
pp. 904-909 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark
Keyword(s):  
Acetic Anhydride ◽  
Carbon Disulfide ◽  
General Rule ◽  
Dielectric Constants ◽  
Excess Volumes ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Heats Of Mixing ◽  
Upper Critical Solution Temperature ◽  
Molar Polarization

The following physical properties of the acetic anhydride – acetone – carbon disulfide system have been investigated: congruent compositions, excess volumes, dielectric constants. For the system acetone – carbon disulfide, the excess volumes and the molar polarizations are much greater than those required by the mixture rule. From this we deduced that this system is very non-ideal and might, at a suitable temperature, form two layers; two liquid layers did indeed form at −73 °C, the upper critical solution temperature occurring somewhere between this temperature and 0 °C. We offer it as a general rule that, if the deviation from additivity of molar polarization is large and positive, two layers will form at a sufficiently low temperature, provided that solid phases do not intervene. This deduction becomes almost a certainty if large positive deviations from additivity of molar volume and large positive heats of mixing are also present.

Heats of mixing in the system acetone – acetic anhydride – carbon disulfide, and the corresponding binary systems, at room temperature

1970 ◽  
Vol 48 (10) ◽  
pp. 1579-1584 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
S. C. Anand
Keyword(s):  
Acetic Anhydride ◽  
Carbon Disulfide ◽  
Room Temperature ◽  
Binary Systems ◽  
Thermodynamic Quantities ◽  
Molar Excess ◽  
Heats Of Mixing ◽  
Partially Miscible ◽  
Binary Section ◽  
Excess Thermodynamic Quantities

A simple calorimeter has been devised by means of which the heats of mixing (molar excess heats) of the following systems have been determined at 22 °C: acetone – acetic anhydride; acetone – carbon disulfide; acetic anhydride – carbon disulfide; and a pseudo-binary section of the ternary system acetone – acetic anhydride – carbon disulfide. From these data the partial molar excess heats have been obtained. All systems are very non-ideal except the system acetone – acetic anhydride, which is almost ideal.For the partially miscible system acetic anhydride – carbon disulfide, the excess thermodynamic quantities of mixing, GE, HE, and TSE, have been calculated,

Selective Hydrogen Bonding Controls Temperature Response of Layer-by-Layer Upper Critical Solution Temperature Micellar Assemblies

Soft Matter ◽  
2021 ◽  
Author(s):  
Aliaksei Aliakseyeu ◽  
Victoria Albright ◽  
Danielle Yarbrough ◽  
Samantha Hernandez ◽  
Qing Zhou ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Methacrylic Acid ◽  
Temperature Response ◽  
Solution Temperature ◽  
Layer By Layer ◽  
Critical Solution Temperature ◽  
Hydrogen Bonding Interactions ◽  
Upper Critical Solution Temperature ◽  
Lbl Films

This work establishes a correlation between the selectivity of hydrogen-bonding interactions and the functionality of micelle-containing layer-by-layer (LbL) assemblies. Specifically, we explore LbL films formed by assembly of poly(methacrylic acid)...

scholarly journals Dielectric Constants of a Binary Solution Near the Critical Solution Temperature

1973 ◽  
Vol 51 (4) ◽  
pp. 545-550 ◽  
Author(s):  
I. Lubezky ◽  
R. McIntosh
Keyword(s):  
High Frequency ◽  
Binary Solution ◽  
Critical Concentration ◽  
Low Frequency ◽  
Dielectric Constants ◽  
Solution Temperature ◽  
Dielectric Losses ◽  
Theoretical Studies ◽  
Critical Solution Temperature ◽  
Experimental Knowledge

The dielectric constants and dielectric losses of solutions of nitrobenzene and 2,2,4-trimethyl pentane have been measured near the critical solution temperature over a concentration range of 22–75% by weight and in the frequency regions of 5–60 and 1000 – 4000 kHz. It was found that below a critical concentration of 35% maxima existed in ε′ and ε″ at a temperature of 0.3 °C above the critical solution temperature. At higher concentrations the maxima disappeared and phase separation was preceded only by changes in the thermal coefficients dε′/dT and dε″/dT. The present study combined with others indicates that two regions of loss exist for the system near the critical temperature: low frequency losses of a conductive nature and high frequency losses of the Debye type. The published experimental knowledge of such systems remains insufficient to enable a thorough test of the theoretical studies published recently by Snider.

scholarly journals Thermo-Tunable Pores and Antibiotic Gating Properties of Bovine Skin Gelatin Gels Prepared with Poly(n-isopropylacrylamide) Network

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2156
Author(s):  
Fang-Chang Tsai ◽  
Chih-Feng Huang ◽  
Chi-Jung Chang ◽  
Chien-Hsing Lu ◽  
Jem-Kun Chen
Keyword(s):  
Hydrogen Bonding ◽  
Incubation Time ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
E Coli ◽  
Polystyrene Nanospheres ◽  
Gelatin Gels ◽  
Bacteria Inhibition ◽  
Tunable Pores

Polystyrene nanospheres (PNs) were embedded in bovine skin gelatin gels with a poly(N-isopropylacrylamide) (PNIPAAm) network, which were denoted as NGHHs, to generate thermoresponsive behavior. When 265 nm PNs were exploited to generate the pores, bovine skin gelatin extended to completely occupy the pores left by PNs below the lower critical solution temperature (LCST), forming a pore-less structure. Contrarily, above the LCST, the collapse of hydrogen bonding between bovine skin gelatin and PNIPAAm occurred, resulting in pores in the NGHH. The behavior of pore closing and opening below and above the LCST, respectively, indicates the excellent drug gating efficiency. Amoxicillin (AMX) was loaded into the NGHHs as smart antibiotic gating due to the pore closing and opening behavior. Accordingly, E. coli. and S. aureus were exploited to test the bacteria inhibition ratio (BIR) of the AMX-loaded NGHHs. BIRs of NGHH without pores were 48% to 46.7% at 25 and 37 °C, respectively, for E. coli during 12 h of incubation time. The BIRs of nanoporous NGHH could be enhanced from 61.5% to 90.4% providing a smart antibiotic gate of bovine skin gelatin gels against inflammation from infection or injury inflammation.

The Acetone – Acetic Anhydride – Carbon Disulfide System: Surface Tension, Viscosity, and Total and Partial Vapor Pressures

1971 ◽  
Vol 49 (13) ◽  
pp. 2183-2192 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
S. C. Anand
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Acetic Anhydride ◽  
Carbon Disulfide ◽  
Vapor Phase ◽  
The Other ◽  
Vapor Pressures ◽  
Free Energies ◽  
Vapor State ◽  
Straight Line

The surface tensions, viscosities, and vapor pressures, total and partial, have been determined as functions of concentration for the following systems: (a) acetone – acetic anhydride; (b) acetone – carbon disulfide; (c) acetic anhydride – carbon disulfide; and (d) pseudo-binary mixtures of (a) and (b), whose compositions lie on a straight line tangential to the plait point of the ternary system.The general behavior of ideal and non-ideal systems, in regard to surface tension and viscosity is discussed. For the system acetone – carbon disulfide, whose vapor phase can be considered ideal, the activities, activity coefficients, excess free energies, enthalpies and entropies of mixing have been obtained from the vapor pressures. The vapor phase of the other three systems contains acetic anhydride which is associated in the vapor state, and for these systems the experimental data are reported without further calculation.

scholarly journals Temperature-Induced Liquid Crystal Microdroplet Formation in a Partially Miscible Liquid Mixture

2019 ◽  
Author(s):  
Mehzabin Patel ◽  
Anand N. Pallipurath Radhakrishnan ◽  
Ludovic Bescher ◽  
Elwin Hunter-Sellars ◽  
Benjamin Schmidt-Hansberg ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Mixture ◽  
Liquid Mixtures ◽  
Solution Temperature ◽  
Material System ◽  
Reversible Process ◽  
Critical Solution Temperature ◽  
Binary Liquid ◽  
Partially Miscible ◽  
Extraction Processes

The controlled formation of microdroplets through temperature variation is an intriguing concept for binary liquid mixtures with a critical solution temperature. Here, we investigate this phenomenon for a blend of methanol (MeOH) and a thermotropic liquid crystal (LC) 4-Cyano-4’-pentylbiphenyl (5CB). A near-room-temperatureinduced phase separation leads to nucleation, growth and coalescence of mesogen-rich droplets. The size and number of the droplets is tunable on the microscopic scale by variation of temperature quench depth and cooling rate. Further cooling induces a phase transition to nematic droplets with radial configuration, well-defined sizes and stability over the course of an hour. This fully reversible process is an interesting material system with relevance in diagnostics, optoelectronics, materials templating and extraction processes.<br>

scholarly journals Temperature-Induced Liquid Crystal Microdroplet Formation in a Partially Miscible Liquid Mixture

2019 ◽  
Author(s):  
Mehzabin Patel ◽  
Anand N. Pallipurath Radhakrishnan ◽  
Ludovic Bescher ◽  
Elwin Hunter-Sellars ◽  
Benjamin Schmidt-Hansberg ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Mixture ◽  
Liquid Mixtures ◽  
Solution Temperature ◽  
Material System ◽  
Reversible Process ◽  
Critical Solution Temperature ◽  
Binary Liquid ◽  
Partially Miscible ◽  
Extraction Processes

The controlled formation of microdroplets through temperature variation is an intriguing concept for binary liquid mixtures with a critical solution temperature. Here, we investigate this phenomenon for a blend of methanol (MeOH) and a thermotropic liquid crystal (LC) 4-Cyano-4’-pentylbiphenyl (5CB). A near-room-temperatureinduced phase separation leads to nucleation, growth and coalescence of mesogen-rich droplets. The size and number of the droplets is tunable on the microscopic scale by variation of temperature quench depth and cooling rate. Further cooling induces a phase transition to nematic droplets with radial configuration, well-defined sizes and stability over the course of an hour. This fully reversible process is an interesting material system with relevance in diagnostics, optoelectronics, materials templating and extraction processes.<br>

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