Surface behaviour of tetrapropylammonium cation at the mercury/solution interface measured by use of controlled convective adsorptive accumulation

1985 ◽  
Vol 50 (11) ◽  
pp. 2525-2534 ◽  
Author(s):  
Ladislav Novotný ◽  
Ivan Smoler
Keyword(s):  
Surface Tension ◽  
Adsorption Isotherms ◽  
Adsorption Energy ◽  
Surface Coverage ◽  
Adsorption Parameters ◽  
Surface Tension Data ◽  
Solution Interface ◽  
Constant Potential ◽  
Drop Time ◽  
Constant Charge

Using drop time technique with long drop times and a controlled convection of the solution the surface tension data of Hg with tetrapropylammonium perchlorate in 0.1 mol l-1 NaClO4 in the concentration range 4 . 10-6 - 3 . 10-3 mol l-1 have been obtained. The corresponding adsorption parameters have been evaluated from the Frumkin isotherm both at constant potential E and at constant charge q. Both E and q could be chosen as an independent electrical variable. The maximum free adsorption energy amounts to approx. -36.5 kJ mol-1. The congruence of adsorption isotherms with respect to E and with respect to q was very well fulfilled for the surface coverage Θ ⪬ 0.6-0.7.

Electrocapillary measurements at low concentrations of surfactants: Adsorption of tetrabutylammonium cation

1983 ◽  
Vol 48 (4) ◽  
pp. 964-975 ◽  
Author(s):  
Ladislav Novotný ◽  
Ivan Smoler ◽  
Jaroslav Kůta
Keyword(s):  
Surface Tension ◽  
Maximum Energy ◽  
Tetrabutylammonium Perchlorate ◽  
Adsorption Parameters ◽  
Surface Tension Data ◽  
Frumkin Isotherm ◽  
Low Concentrations ◽  
Drop Time

Using drop-time technique with long drop-times achieved by means of a spindle-type capillary with the combination of a interrupted convection the surface tension data of tetrabutylammonium perchlorate in 0.1 mol l-1 NaClO4 in the concentration range 3 . 10-3 mol l-1 down to 10-7 mol l-1 could be measured. The corresponding adsorption parameters have been evaluated both from Langmuir (for Θ ⪬ 0.8) and Frumkin isotherm. The maximum energy of adsorption amounts to -48.1 kJ . mol-1. The dependence of E vs log c (Yesin-Markov plot) carried out in the concentration range 10-7 to 10-3 mol l-1 showed a S-shaped curve.

Adsorption of long-chain ions. II

1958 ◽  
Vol 245 (1242) ◽  
pp. 429-433 ◽  
Keyword(s):  
Surface Tension ◽  
Adsorption Isotherms ◽  
Surface Pressure ◽  
Water Surface ◽  
Surface Coverage ◽  
Bulk Concentration ◽  
Adsorbed Film ◽  
Long Chain

In part I we have discussed adsorption equations of the form n = f (c); these are true ‘adsorption isotherms’, n being the surface coverage in molecules per square centimetre, and c the equilibrium bulk concentration in moles per litre. There have been proposed, however, several relations of the form II = ϕ(c), where II is the surface pressure of the adsorbed film, defined as the surface tension lowering due to this film. The best-known of these is that which Szyszkowski (1908) put forward exactly 50 years ago; it is empirical and refers to the adsorption of neutral molecules at the air/water surface.

Electrosorption of vinyltriphenyl and propargyltriphenylphosphonium cations from methanolic solutions at the dropping and hanging mercury drop electrodes

1986 ◽  
Vol 64 (12) ◽  
pp. 2279-2283
Author(s):  
Anastasia Christodoulou ◽  
Anastos Anastopoulos ◽  
Demetrios Jannakoudakis
Keyword(s):  
Adsorption Isotherms ◽  
Mercury Electrode ◽  
Adsorption Parameters ◽  
Methanolic Solution ◽  
Solution Interface ◽  
Ionic Adsorption ◽  
Interfacial Behaviour

The interfacial behaviour of vinyltriphenyl and propargyltriphenylphosphonium cations at the mercury electrode – methanolic solution interface is studied by phase selective ac polarography using dropping Hg electrodes of short (≤5 s) and long [Formula: see text] drop times and the hanging Hg drop electrode.The various adsorption parameters are determined on the basis of non-ionic adsorption isotherms involving capacitance data independent as well dependent on time.

Probing Inclusion Complexes of Pentoxifylline and Pralidoxim inside Cyclic Oligosaccharides by Physicochemical Methodologies

2019 ◽  
Vol 233 (8) ◽  
pp. 1109-1127
Author(s):  
Biraj Kumar Barman ◽  
Kanak Roy ◽  
Mahendra Nath Roy
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Inclusion Complexes ◽  
Apparent Molar Volume ◽  
Nmr Spectra ◽  
Drug Delivery Systems ◽  
Surface Tension Data ◽  
H Nmr ◽  
Ft Ir ◽  
Inclusion Phenomena

Abstract Structurally different Molecules namely Pentoxifylline and Pralidoxim were chosen along with α-cyclodextrin and β-cyclodextrin to study host-guest inclusion phenomena. The formations of host guest inclusion complexes were confirmed by studying 1H-NMR spectra, FT-IR spectra, apparent molar volume and viscosity co-efficient. The stabilities of inclusion complexes were compared calculating the binding constant from UV-VIS spectroscopic study. The 1:1 stoichiometry of the inclusion complexes were also determined by analysing the Jobs plot and surface tension data. The values for Gibbs’ free energy were found negative for both the processes. Based on all the above experiments the inclusion processes were found feasible for both the compounds. These types of inclusion complexes are of high interest in the field of research and industry as these are used as drug delivery systems.

scholarly journals Effect of Pesticide Addition Sequence on the Preparation of Phytosanitary Spray Solutions

2019 ◽  
Vol 37 ◽  
Author(s):  
M.F.T. RAMOS ◽  
R.T.S. SANTOS ◽  
D.P. ALMEIDA ◽  
J.F.D. VECHIA ◽  
M.C. FERREIRA
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Propionic Acid ◽  
Biological Effect ◽  
Surface Coverage ◽  
Mineral Oil ◽  
Application Rate ◽  
Physicochemical Interactions ◽  
Effect Of Treatment ◽  
Droplet Method

ABSTRACT: The addition of adjuvants to herbicide solutions is aimed at preserving or enhancing the biological effect of treatment. However, it is commonly performed without knowledge of the physicochemical interactions between products. This study aimed to assess the effects of different addition sequences of the herbicide aminopyralid + fluroxypyr and adjuvants in the preparation of phytosanitary spray solutions on the surface tension and contact angle. Two experiments were carried out with herbicide doses of 1 and 2 L ha-1 associated with the adjuvants mineral oil (MO), silicone-polyether copolymer (SIL), and a mixture of phosphatidylcholine (lectin) and propionic acid (LEC), all at a proportion of 0.3% v v-1. The application rate was 150 L ha-1. Surface tension was measured by the pendant droplet method. Contact angle was measured on the adaxial and abaxial surfaces of leaves of the pasture weed Senna obtusifolia and parafilm. Preparation sequence did not change the contact angle on any of the analyzed surfaces at a dose of 1 L ha-1 of herbicide. For the dose of 2 L ha-1, the adjuvants SIL and LEC showed a higher spreading when previously added to the herbicide. MO resulted in a higher spreading when added after the herbicide, with higher surface coverage. Therefore, the preparation sequence influences the dispersion of phytosanitary spray solutions on targets.

scholarly journals Influence of Magnetic Field on Evaporation Rate and Surface Tension of Water

2018 ◽  
Vol 2 (4) ◽  
pp. 68 ◽  
Author(s):  
Emil Chibowski ◽  
Aleksandra Szcześ ◽  
Lucyna Hołysz
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Evaporation Rate ◽  
Water Evaporation ◽  
Water Molecules ◽  
Surface Tension Data ◽  
Ring Magnet ◽  
The Magnetic Field

Using neodymium ring magnets (0.5–0.65 T), the experiments on the magnetic field (MF) effects on water evaporation rate and surface tension were performed at room temperature (22–24 °C). In accordance with the literature data, the enhanced evaporation rates were observed in the experiments conducted in a period of several days or weeks. However, the evaporated amounts of water (up to 440 mg over 150 min) in particular experiments differed. The evaporated amounts depended partially on which pole of the ring magnet was directed up. The relatively strong MF (0.65 T) caused a slight decrease in surface tension (−2.11 mN/m) which lasted longer than 60 min and the memory effect vanished slowly. The surface tension data reduced by the MF action are reported in the literature, although contrary results can be also found. The observed effects can be explained based on literature data of molecular simulations and the suggestion that MF affects the hydrogen bonds of intra- and inter-clusters of water molecules, possibly even causing breakage some of them. The Lorentz force influence is also considered. These mechanisms are discussed in the paper.

scholarly journals Gas-Solid Interaction

1968 ◽  
Vol 23 (7) ◽  
pp. 979-984 ◽  
Author(s):  
Manlio Sanesi ◽  
Vittoriano Wagner
Keyword(s):  
Adsorption Energy ◽  
Surface Coverage ◽  
Aluminium Oxide ◽  
Dispersion Forces ◽  
Heats Of Adsorption ◽  
Linear Alkanes ◽  
London Dispersion ◽  
London Dispersion Forces

The heats of adsorption on weakly activated γ-aluminium oxide for a number of linear alkanes (from n-butane to n-nonane) and for 2.2.4-trimethylpentane have been determined by GSC and extrapolated to zero surface coverage.The dependance of the adsorption energy on the number of carbon atoms is discussed on the basis of the bidimensional gas model: it is shown that the interactions of the adsorbates with the oxidic surface are mainly due to London dispersion forces.

scholarly journals Modeling the surface tension of complex, reactive organic–inorganic mixtures

2013 ◽  
Vol 13 (21) ◽  
pp. 10721-10732 ◽  
Author(s):  
A. N. Schwier ◽  
G. A. Viglione ◽  
Z. Li ◽  
V. Faye McNeill
Keyword(s):  
Surface Tension ◽  
Organic Compounds ◽  
Atmospheric Aerosols ◽  
Goodness Of Fit ◽  
Cloud Droplet ◽  
Aqueous Mixtures ◽  
Surface Tension Data ◽  
Inorganic Systems ◽  
Experimental Surface ◽  
Using Data

Abstract. Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as heterogeneous reactivity, ice nucleation, and cloud droplet formation. We present new experimental data for the surface tension of complex, reactive organic–inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2–6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two semi-empirical surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well described by a weighted Szyszkowski–Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling of aerosol systems because the Henning model (using data obtained from organic–inorganic systems) and Tuckermann approach provide similar modeling results and goodness-of-fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.

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