Maximum Bubble Pressure Research Articles

Quantitative evaluation of clusters formed in magnetic fluid with maximum bubble pressure

Quantitative evaluation of clusters formed in magnetic fluid with maximum bubble pressure

Synthesis of a lignin-based surfactant through amination, sulfonation, and acylation

ABSTRACTA simple and effective chemical method based on Mannich reaction, sulfonation, and acylation was adopted to anchor the hydrophilic sulfonic groups and lipophilic long carbon chains onto alkaline lignin. The obtained products were characterized by Fourier transform infrared spectroscopy (FTIR) and elemental analysis, and the surface activity was evaluated by interfacial tension, which was determined by a maximum bubble pressure method. The results demonstrated that the ASAL showed high surface activity in comparison to lignosulfonate and the interfacial tension reached 5.0 (10−3 N · m−1) when the mass fraction of ASAL was 5%, in agreement with the properties of good surfactants.**

On-chip microfluidic generation of monodisperse bubbles for liquid interfacial tension measurement

A novel microfluidic method for measuring liquid interfacial tension using monodisperse microbubbles generated in situ has been proposed. Instead of bulky gas supply used in traditional microfluidic devices, microbubbles are efficiently generated via water electrolysis in the devices. Since the bubble formation frequency is related to the interfacial tension of liquids used, thus, precisely measuring the interfacial tension of liquids in microfluidics can be achieved. In addition, it is found that during the microbubble formation, the electrochemical potential fluctuates regularly at controlled electrolysis current, and the fluctuating period depends on the microbubble generation rate. Therefore, the change in electrochemical potential can be directly used to monitor the bubble formation process, which avoids the use of an external optical detection system. As demonstration, the interfacial tension of isopentanol solutions with different concentrations was measured, and the results show good agreement with the ones obtained using the maximum bubble pressure method, confirming the accuracy of the present method. The proposed strategy offers a simple, low cost and accurate solution to measure the liquid interfacial tension confined in microfluidic channels. The present platform is easily constructed and facilely manipulated in common laboratories, which is expected to be widely used in microfluidic-based research and application fields.

Development of Maximum Bubble Pressure Method for Surface Tension Measurement of High Viscosity Molten Silicate

A surface tension measurement method based on the maximum bubble pressure (MBP) method was developed in order to precisely determine the surface tension of molten silicates in this study. Specifically, the influence of viscosity on surface tension measurements was quantified, and the criteria for accurate measurement were investigated. It was found that the MBP apparently increased with an increase in viscosity. This was because extra pressure was required for the flowing liquid inside the capillary due to viscous resistance. It was also expected that the extra pressure would decrease by decreasing the fluid velocity. For silicone oil with a viscosity of $$1000\,\hbox {mPa}{\cdot }\hbox {s}$$ , the error on the MBP could be decreased to +1.7 % by increasing the bubble detachment time to $$300\,\hbox {s}$$ . However, the error was still over 1 % even when the bubble detachment time was increased to $$600\,\hbox {s}$$ . Therefore, a true value of the MBP was determined by using a curve-fitting technique with a simple relaxation function, and that was succeeded for silicone oil at $$1000\,\hbox {mPa}{\cdot } \hbox {s}$$ of viscosity. Furthermore, for silicone oil with a viscosity as high as $$10\,000\,\hbox {mPa}{\cdot }\hbox {s}$$ , the apparent MBP approached a true value by interrupting the gas introduction during the pressure rising period and by re-introducing the gas at a slow flow rate. Based on the fundamental investigation at room temperature, the surface tension of the $$\hbox {SiO}_{2}$$ –40 $$\hbox {mol}\%\hbox {Na}_{2}\hbox {O}$$ and $$\hbox {SiO}_{2}$$ –50 $$\hbox {mol}\%\hbox {Na}_{2}\hbox {O}$$ melts was determined at a high temperature. The obtained value was slightly lower than the literature values, which might be due to the influence of viscosity on surface tension measurements being removed in this study.

Adsorption and Co-Adsorption of Polyaldehyde Dextran Nanoparticles and Nonionic Surfactant at an Air–Water Interface: Potential Implications for Pulmonary Drug Delivery

Abstract Measurements of dynamic surface tension were carried out in aqueous systems (water or 0.1 mM Triton X-100) comprising nanoparticles formed from chemically modified polyaldehyde dextran (PAD). The nanostructures, considered as potential drug carriers in aerosol therapy, were obtained from biocompatible polysaccharides by successive oxidation and reactive coiling in an aqueous solution. The dynamic surface tension of the samples was determined by the maximum bubble pressure (MBP) method and by the axisymmetric drop shape analysis (ADSA). Experiments with harmonic area perturbations were also carried out in order to determine surface dilatational viscoelasticity. PAD showed a remarkable surface activity. Ward-Tordai equation was used to determine the equilibrium surface tension and diffusion coefficient of PAD nanoparticles (D = 2.3×10-6 m2/s). In a mixture with Triton X-100, PAD particles showed co-adsorption and synergic effect in surface tension reduction at short times (below 10 s). Tested nanoparticles had impact on surface rheology in a mixed system with nonionic surfactant, suggesting their possible interactions with the lung surfactant system after inhalation. This preliminary investigation sets the methodological approach for further research related to the influence of inhaled PAD nanoparticles on the lung surfactant and mass transfer processes in the respiratory system.

Tetramethyl-6-decyne-5,8-diol polyoxyethylene: Their dynamic surface activity and dynamic spreading behavior in solutions

Abstract The dynamic surface activity in solutions, dynamic spreading on low energy surfaces of alkynol polyoxyethylene ether with two different units were evaluated by using the Wilhelmy-plate, maximum bubble pressure, contact angle method. The dynamic surface activity was depicted by using the classical Rosen model and the dynamic spreading was analyzed by decay function. The static contact angle (θe value) and spread rate (K value) should be taken into account in evaluating the effectiveness and efficiency of spread.

Surface tension of dilute alcohol-aqueous binary fluids: n-Butanol/water, n-Pentanol/water, and n-Hexanol/water solutions

Surface tension of pure fluids, inherently decreasing with regard to temperature, creates a thermo-capillary-driven (Marangoni) flow moving away from a hot surface. It has been known that few high-carbon alcohol-aqueous solutions exhibit an opposite behavior of the surface tension increasing with regard to temperature, such that the Marangoni flow moves towards the hot surface (self-rewetting effect). We report the surface tensions of three dilute aqueous solutions of n-Butanol, n-Pentanol and n-Hexanol as self-rewetting fluids measured for ranges of alcohol concentration (within solubility limits) and fluid temperatures (25–85 °C). A maximum bubble pressure method using a leak-tight setup was used to measure the surface tension without evaporation losses of volatile components. It was found from this study that the aqueous solutions with higher-carbon alcohols exhibit a weak self-rewetting behavior, such that the surface tensions remain constant or slightly increases above about 60 °C. These results greatly differ from the previously reported results showing a strong self-rewetting behavior, which is attributed to the measurement errors associated with the evaporation losses of test fluids during open-system experiments.

Dynamic Surface Tension of Heterogemini Surfactants with Quaternary Ammonium Salt and Gluconamide or Sulfobetaine Headgroups.

Dynamic surface tensions of two types of heterogemini surfactants with nonidentical hydrophilic headgroups consisting of a quaternary ammonium salt (cationic) and a gluconamide (nonionic) or sulfobetaine (zwitterionic) group were measured using the maximum bubble pressure method. For these compounds, effects of alkyl chain length, structure of the hydrophilic groups, and surfactant concentration were investigated using diffusion coefficients and parameter x. The parameter x is related to the difference between the energies of adsorption and desorption of the surfactant. The values of x of heterogemini surfactants increased as the alkyl chain length increased, and they were slightly larger than that for the corresponding monomeric surfactant. This is because of an increase in hydrophobicity caused by two alkyl chains, as well as interactions between two different hydrophilic groups. Adsorption rate of the heterogemini surfactants decreased with increasing alkyl chain length, indicating slow dynamics, and inhibited adsorption to the air/water interface as the chain length increased. However, at higher concentrations, the heterogemini surfactants showed rapid and effective adsorption and increased adsorption rates at higher concentrations. Diffusion coefficients of the heterogemini surfactants decreased with increasing concentrations for all chain lengths, indicating diffusion of the solute molecules to the subsurface and adsorption of the solute from the subsurface to the surface.

Surface tension, electrical conductivity and viscosity of the LiCl-NaCl-ZnCl2 molten system

Three physicochemical properties have been investigated for LiCl-NaCl-ZnCl2 molten system in restricted concentration range up to xZnCl2=0.20. Surface tension, electrical conductivity and viscosity have been determined using maximum bubble pressure method, method based on the principle of phase shift measurement and torsion pendulum method. Concentration dependencies of these properties have been calculated for 923, 973 a 1023K and plotted for 973K. Results have shown that the presence of zinc chloride does not significantly influence determined physico-chemical properties and their change is gradual.

Surface tension measurement of oil/refrigerant mixture by maximum bubble pressure method

Lubrication oil used in refrigerant compressors forms oil mist in the compressor shell. Some of the oil mist is discharged into a refrigeration cycle with refrigerant and causes degradation of heat transfer in heat exchangers. Since the generation of the oil mist is related to the Weber number, it is necessary to measure the surface tension of the oil/refrigerant mixture before discussing the oil mist generation in the compressor. In this study, the maximum bubble pressure method was adapted to measure the surface tension of PAG (polyalkylene glycol) oil/CO2 mixture. The density of the mixture needed for the measurement was also carried out. It was found that the surface tension of PAG/CO2 mixture sharply decreases with an increase in the concentration of the refrigerant in the mixture. The surface tension of the mixture under 10 MPa and 100 °C is estimated to be 14.6 mN m−1 by an extrapolation.

MODELING OF THE SURFACE TENSION OF COLLOIDAL SUSPENSIONS

Surface tension is one of the fundamental properties of the colloids, which can be altered by concentration and size of colloidal particles. In the current work, modeling of the surface tension of suspension as it would be analyzed by maximum bubble pressure method has been performed. A new modified equation to correlate the surface tension with the bubble pressure is derived by applying fundamental thermodynamic relation considering the presence of particles in suspension and curvature of the interface between the particles and bubbles inside liquid. Moreover, the change of particles concentration in air–water interface due to capillary force is also considered. The predicted surface tension using the developed model has been verified by numerous experimental data with deviation less than 5% in most of cases. It was found that the calculated surface tension is altered by contact angle and particle radius as well as particle concentration. The obtained model may have potential application to predict the surface tension of colloidal suspension.

Dynamic Surface Activity and Dynamic Spreading Behavior of Isotridecanol Ethoxylates Solutions

The dynamic surface activity in solutions and dynamic spreading on low-energy surfaces of isotridecanol ethoxylates with two different units were investigated by using the Wilhelmy plate, maximum bubble pressure, and contact angle method. The dynamic surface activity was analyzed by using the classical Rosen model, and the dynamic spreading was depicted by decay function. The equilibrium contact angle (θe value) and the spread rate (K value) were suggested to evaluate effectiveness and efficiency of spreading.

Experimental Study on Foam Properties of Mixed Systems of Silicone and Hydrocarbon Surfactants

AbstractSilicone surfactants are inevitably involved in industrial applications in combination with hydrocarbon surfactants, but properties of the mixtures of silicone and hydrocarbon surfactants have received little attention, especially foam properties of the mixtures. In this study, aqueous solutions of respective binary mixtures of a nonionic silicone surfactant with anionic, cationic, and nonionic hydrocarbon surfactants were prepared for evaluation of their foam properties. Surface tension of aqueous solutions of the mixtures were measured with the maximum bubble pressure method. Foaming ability and foam stability of the mixtures were then evaluated with the standard Ross–Miles method. The findings show that the addition of the silicone surfactant results in a decrease in surface tension for aqueous solutions of the hydrocarbon surfactants. The critical micelle concentration (CMC) of the hydrocarbon surfactants is also changed by the additive silicone surfactant. Additionally, clear foam synergistic effects were observed in the mixtures of silicone and hydrocarbon surfactants, regardless of the ionic types of the hydrocarbon surfactant. The foam stability of the hydrocarbon surfactant was shown to generally improve with the increasing concentration of the silicone surfactant. Even so, aqueous solutions of different ionic hydrocarbon surfactants in the presence of the silicone surfactant will give different foam stabilities. The results of the present study are meant to provide guidance for the practical application of foams generated by the mixtures of the silicone and hydrocarbon surfactants.

Experimental Study on the Surface Tension of Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O Nanofluid

Due to the good performance of thermal conductivity, nanofluids are regarded as a new type of heat transfer working medium, which have huge potential value. The addition of nanoparticles makes nanofluids exhibit different thermal properties from the base fluids. In this experiment, the maximum bubble pressure method was adopted to measure the surface tension of Al2O3-H2O nanofluids whose nanoparticle sizes are 10 nm and 20 nm with four different volume fractions (1%, 1.5%, 2% and 1.5%), and 50 nm and 100 nm with the volume fraction of 2.5%. The temperatures of nanofluids are within the scope of 18 °C to 30 °C. The surface tension ratio (the ratio of surface tension value of nanofluids to its base fluids) is also calculated at different temperature points. Results show that the surface tension of nanofluids decreases with the elevation of temperature and decreases with the increase of volume fraction. For different temperatures and particle sizes of nanofluids, there exists a corresponding critical concentration value. Only reaching the value, the addition of nanoparticles can reduce the surface tension of the base fluids.

Composition and Dynamic Adsorption of Crude Oil Components Dissolved in Synthetic Produced Water at Different pH Values

The effect of pH on the extent and type of dissolved components in synthetic produced water samples prepared from seven crude oils was investigated. More nitrogen containing compounds, probably due to improved water solubility of pyridinic nitrogen functionalities, were seen at the low pH. The affinity of the water-soluble compounds for air–water interfaces was in most cases higher at higher pH. This was due to increased oxygen content in the water-soluble species, probably associated with carboxylic acid functionalities. Differences in the affinity of water-soluble crude oil components to gas bubbles are anticipated to influence the oil removal efficiency by gas flotation. The dynamic interfacial adsorption was followed by a maximum bubble pressure tensiometer, while the dissolved species were characterized by total organic carbon measurements, total nitrogen measurements, FT-IR spectroscopy, and UV/vis spectroscopy.

Physicochemical Properties of the (LiF + CaF2)eut + LaF3 System: Phase Equilibria, Volume Properties, Electrical Conductivity, and Surface Tension

The physicochemical behavior of the molten system (LiF (1) + CaF2 (2))eut + LaF3 (3) has been studied and the phase equilibria, density and volume properties, electrical conductivity, and surface tension have been selected for investigation. Well-established methods for determination of these physicochemical properties of molten salts have been used, such as thermal analysis, the Archimedean method of hydrostatic weighing, and the phase shift and maximum bubble pressure methods. A significant change in all investigated properties was detected in the region of x3 = 0.04–0.06. In regard to phase equilibria, this region is close to and may contain the eutectic point; in volumetric properties, the initial volume contraction (on increasing mol %) starts to reverse. A sharp change of electrical conductivity reflects the changes in ionic composition, and surface tension also shows different behavior below and above this region.

Influence of Zinc on the Surface Tension, Density and Molar Volume of (Ag-Sn)eut +Zn Liquid Alloys

The dilatometric and maximum bubble pressure methods were applied for the measurements of the density and surface tension of liquid (Ag-Sn)eut+Zn lead-free solders. The experiments were carried out in the temperature range from 515 to 1223 K for the alloys of the zinc concentration equaling 0.01, 0.02, 0.04, 0.05, 0.1 and 0.2 of the mole fraction. It was found that the temperature dependence of both the density and the surface tension could be thought as linear, so they were interpreted by straight line equations. The experimental data of the molar volume of the investigated alloys were described by the polynomial dependent on the composition and temperature.Calculations of the surface tension by Butler’s equation were conducted and confronted with the experimental data. Some significant deviations between the experimental and the calculated surface tension were observed. They reached almost 40 mNm-1. The observed changes of the density and surface tension caused by the zinc addition to the Ag-Sn eutectic were discussed with the consideration of the thermodynamic properties and the influence of a small quantity of impurities in a protective gas atmosphere.

Surface tension and density data for Fe–Cr–Mo, Fe–Cr–Ni, and Fe–Cr–Mn–Ni steels

The temperature dependence of surface tension and density for Fe–Cr–Mo (AISI 4142), Fe–Cr–Ni (AISI 304), and Fe–Cr–Mn–Ni TRIP/TWIP high-manganese (16 wt% Cr, 7 wt% Mn, and 3–9 wt% Ni) liquid alloys are investigated using the conventional maximum bubble pressure (MBP) and sessile drop (SD) methods. In addition, the surface tension of liquid steel is measured using the oscillating droplet method on electromagnetically levitated (EML) liquid droplets at the German Aerospace Centre (DLR, Cologne). The data of thermophysical properties for Fe–Cr–Mn–Ni is of major importance for modeling of infiltration and gas atomization processes in the prototyping of a “TRIP-Matrix-Composite.” The surface tension of TRIP/TWIP steel increased with an increase in temperature in MBP as well as in SD measurement. The manganese evaporation with the conventional measurement methods is not significantly high within the experiments (∆Mn < 0.5 %). The temperature coefficient of surface tension (dσ/dT) is positive for liquid steel samples, which can be explained by the concentration of surface active elements. A slight influence of nickel on the surface tension of Fe–Cr–Mn–Ni steel was experimentally observed where σ is decreased with increasing nickel content. EML measurement of high-manganese steel, however, is limited to the undercooling state of the liquid steel. The manganese evaporation strongly increased in excess of the liquidus temperature in levitation measurements and a mass loss of droplet of 5 % was observed.

Dynamic surface tension of С10ЕО8 at the aqueous solution/hexane vapor interface as measured by bubble pressure tensiometry

Abstract The dynamic surface tension of aqueous solutions of C10EO8 at the interfaces with air and saturated hexane vapor was measured by the maximum bubble pressure tensiometer BPA for adsorption times t ≥ 0.01 s. It can be shown that the dynamic surface pressure of C10EO8 solutions in a saturated hexane atmosphere increases at short adsorption times with increasing surfactant concentration. The theory of diffusion controlled adsorption of two surfactants from the water and gas phases, respectively, was used for data analysis. The obtained experimental results agree with a model based on a reorientation of the C10EO8 molecules, assuming a strong intermolecular interaction between hexane and C10EO8 molecules in the surface layer. Alternatively, an additional enhancement of C10EO8 adsorption activity can be assumed due to the presence of hexane molecules at the interface.

Dynamic tensiometry studies on interactions of novel therapeutic inhalable powders with model pulmonary surfactant at the air–water interface

Abstract Assessing the influence of therapeutic formulations on biophysical properties of lung surfactant is an essential step in optimal design of pharmaceutical products intended for inhalation. In the present study, maximum bubble pressure (MBP) tensiometry was employed to evaluate the physicochemical impact of several novel multifunctional composite powders, suitable for drug delivery by inhalation, on the dynamic activity of model pulmonary surfactant at the air–water interface. Bi- and tri-component powders consisted of mannitol or dextran, N-acetylcysteine and disodium cromoglycate were obtained by spray drying technique and subsequently their interaction with modified bovine surfactant extract (Survanta) were analysed. Several dynamic surface tension parameters were investigated as measures of alteration of surface activity in Survanta-powder solutions. All discussed powders demonstrated significant impact on surface activity of Survanta solution, either positive or negative, depending on powders composition and concentration. Although it is problematic to explain all observed effects in the framework of known mechanisms, the present study provides a new insight into the possible changes in the dynamic interfacial behaviour of pulmonary surfactant after therapeutic interventions. Obtained results may be applied during development of more effective and safe medical products suitable for drug delivery by inhalation.