Wyniki wyszukiwania - Biblioteka Nauki

1

Nanopores with controlled profiles in track - etched membranes

100%

Sartowska B. A.

Nukleonika

|

2012

|

tom Vol. 57, No. 4

575-579

EN

Track-etched membranes are porous systems consisting of a polymer foil with thin channels-pores - from surface to surface. The increasing interest in this kind of material is connected with the development of nanoporous materials with unique properties such as diode-like effects in membranes with highly asymmetrical nanopores. The materials can be used for molecular sensors and atom beam optics, development of nanocapillary bodies for modelling the transport of molecules and ions in constrained volumes. Control over pore geometry opens the way to a number of new applications of track-etch membranes (TMs). The nanopores were obtained by the ion-track etching method using surfactant-doped alkaline solutions. Control over the pore profile and dimensions was achieved by varying the alkali concentration in the etchant and the etching time. The pore geometry was characterized in detail using field-emission scanning electron microscopy (SEM). SEM images of the surfaces and cleavages of TMs with different pore morphology are shown.

2

Rheological properties of water solutions of non-ionic surfactants

100%

Drzazga M. , Kostrzewa E. , Gierczycki A.

Chemical and Process Engineering

|

2010

|

tom Vol. 31, z. 3

387-394

EN

Rheological properties of diluted water solutions of non-ionic surfactants such as ethoxylated unsaturated fatty alcohols Rokanol K3, Rokanol K7 and Rokanol Ł18, as well as the product of ethoxylation of technical stearin Rokacet S7 were experimentally examined. In mathematical description of these solutions the power law Ostwald.de Waele model has been employed. Effects of temperature, concentration and structure of surfactants were also tested. An impact of mass ratio of two surface active agents on properties of a binary solution was also examined.

PL

Przedstawiono wyniki badań właściwości reologicznych rozcieńczonych wodnych roztworów niejonowych związków powierzchniowo czynnych, takich jak oksyetylenowane nienasycone alkohole tłuszczowe Rokanol K3, Rokanol K7 i Rokanol Ł18 oraz produkt oksyetylenowania stearyny technicznej Rokacet S7. Do opisu matematycznego roztworów wykorzystano potęgowy model Ostwalda.de Waele. Zbadano wpływ takich czynników, jak stężenie, struktura cząsteczki surfaktanta oraz temperatura na właściwości roztworów oraz zależność lepkości pozornej roztworów dwóch różnych surfaktantów od ich stosunku masowego w roztworze.

3

Foams Stabilized with Nanoparticles for Gas Well Deliquification

100%

Knapik E. , Stopa J. , Marzec A.

Polish Journal of Chemical Technology

|

2014

|

tom 16

|

nr 2

114-117

EN

This study examined the interaction of solid nanoparticles and anionic and non-ionic surfactant at an air–water interface. Aqueous foams stabilized by silica nanoparticles in water with different levels of salinity were studied in detail. The stability of solid/surfactant dispersion was evaluated visually. Nanoparticles content impact and concentration of surfactant on the foamability, deliquification of foams and structure of wet foams were studied. It was found that the foamability of dispersion depends either on the surfactant concentration or on the nanoparticles concentration. The adsorption of hydrophobically modified silica particles and surfactants reduces the air/water interface tension. The results of the examinations showed that the use of nanoparticles allows to increase the efficiency of brine unloading even up to 20%. Surfactant particle and nanosilica present synergistic action, use of 4 wt% of nanoparticles allows to reduce surfactant consumption up to half. The cost of the preparation of the proposed dispersion is slightly higher, about 5%, compared to the sole surfactant.

4

Determination of cadmium in the presence of surfactants with the controlled growth mercury electrode

100%

Migdalski J.

Chemia Analityczna

|

1999

|

tom Vol. 44, No. 2

279-290

EN

An electroanalytical procedure for the solutions contaminated with surface-active sub-stances (SAS) is presented. The procedure is based on current-time curves (recorded within a step-like growing period of the Hg-drop) which enable the minimization or even elimination of systematic errors resulting from an accidental contamination with SAS. A practical application is demonstrated with 0.1mmoll-l Cd(ll) solution contami-nated with Triton X-114 or 3,4-dichlorobenzyltriphenylphosphonium chloride (Eulan) as the selected surface-active substances.

PL

Zaprezentowano procedurę elektrochemicznej analizy roztwor6w zanieczyszczonych związkami powierzchniowo aktywnymi. Procedura ta, wykorzystująca krzywe prąd-czas (rejestrowane w czasie skokowego narastania powierzchni kropli Hg) pozwala zminimalizować lub nawet wyeliminować błędy systematyczne, będące wynikiem przy-padkowego zanieczyszczenia roztworu związkami powierzchniowo aktywnymi. Prakty-czne zastosowanie pokazano na przykładzie 0.1 mmoll-l roztworu Cd(ll) zawierającego r6żne ilości Tritonu X-114 lub Eulanu.

5

Detailed experimental study of bubble adhesion on hydrophobic surface

100%

Basařová P. , Soušková K.

Physicochemical Problems of Mineral Processing

|

2018

|

tom Vol. 54, iss. 1

111--123

EN

This work is focused on the detailed experimental study of bubble adhesion on a hydrophobic solid surface. The frame rate 16000 fps was used in side view arrangement in order to capture in detail the three-phase contact line expansion and bubble shape changes. Experiments were done in pure water and in solutions of the anionic surfactant sodium dodecyl sulphate in low, medium and high concentrations. It was found out that the rupture of a liquid film is not symmetrical with respect to the vertical axis of the bubble symmetry. This asymmetry of TPC line formation leads to bubble surface oscillations and asymmetry in dynamic contact angles. These dynamic mechanisms are diminished with increasing surfactant concentration. The non-linearity of expansion velocity was also observed. In the case of high bubble surface mobility, the expansion velocity first decreases and after few milliseconds, the second velocity maximum emerges caused by kinetic energy dissipation. In surfactant solutions, the arising Marangoni stresses should be taken into account because the expansion velocity increases in the first moments of TPC line expansion. Existing models, such as hydrodynamic and molecular-kinetic, are not able to incorporate with bubble oscillations in pure liquids as well as the non-monotonic curve of expansion velocity profile in surfactant solutions.

6

Synthesis and characterization of nanoscale Bi2Cu0.1V0.9O5.35 powders by solution-based chemical methods

100%

Guo M. , Deng H. , Yang P.

Materials Science Poland

|

2009

|

tom Vol. 27, No. 4/1

1055--1066

EN

Nanocrystalline Bi2Cu0.1V0.9O5.35 (BCVO) powders were synthesized by solution-based chemical methods. Materials have been characterized by the thermogravimetric analysis, X-ray diffraction, and scanning/transmission electron microscopy. The sintering temperatures to complete phase transition are above 330 °C, 320 °C and 470 °C for the primary powders obtained by the sol-gel technique, an ethylenediaminetetra acetate-citrate combustion gel route and a modified reversing titration co-precipitation method (RP), respectively, which were much lower than the 600 °C required by conventional solid state method (SS). The powders synthesized by EC with 2 wt. % of surfactant, polyethylene glycol PEG 4000 have rather a narrow size distribution, within 30-50 nm, and as the PEG 4000 content increases, they form agglomerates irregular in shapes. In RP the optimal concentration of PEG 4000 is about 5 wt. % and the average grain size of the sample is 20 nm. The modified reaction in homogeneous solutions can be controlled to produce uniform BCVO nanoparticles.

7

Effect of Surfactant Types on the Size of Tin Oxide Nanoparticles

100%

Boran F. , Çetinkaya S. , Şahin M.

Acta Physica Polonica A

|

2017

|

tom 132

|

nr 3

546-548

EN

In this study, tin oxide (SnO₂) nanoparticles were synthesized by hydrothermal method in the presence of hydrazine and ammonia by adding surfactant for 12 h in a Teflon autoclave at 100°C reaction temperature. Tin(II) chloride hydrate as an inorganic precursor, hexadecyl trimethyl ammonium bromide (CTAB), and tetrapropyl ammonium bromide (TPAB) as cationic, and sodium dodecyl sulfonate (SDS) as anionic surfactants were used. The results showed that the size and shape of nanoparticles depended on the surfactant types. The nanoparticles sizes between 17.5 and 19.7 nm were obtained by changing types of surfactants. Synthesized tin oxide nanoparticles were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and the Fourier transform infrared spectroscopy.

8

Surfactant-assisted synthesis and characterization of hydroxyapatite nanorods under hydrothermal conditions

100%

Salarian M. , Solati-Hashjin M. , Sara Shafiei S. , Goudarzi A. , Salarian R. , Nemati A.

Materials Science Poland

|

2009

|

tom Vol. 27, No. 4/1

961--971

EN

Hydroxyapatite (HAp) nanorods with uniform morphology and controllable size were successfully synthesized by precipitating Ca(NO3)2o4H2O and (NH4)2HPO4 in the presence of cetyltrimethylammonium bromide (CTAB) and polyethylene glycol 400 (PEG 400) as cationic surfactant and non-ionic cosurfactant, respectively, under hydrothermal conditions. The effect of hydrothermal temperature on the composition, morphology and size of HAp particles was studied using X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM). Results revealed that the morphology and size of HAp particles can be effectively controlled by the presence of CTAB and PEG surfactants. In addition, the temperature of the hydrothermal treatment plays an important role in controlling the morphology and size of HAp particles. The aspect ratio of rod-like particles increases with the increase in the hydrothermal temperature. Moreover, the crystallinity of HAp powders increases with the increase in the hydrothermal temperature. The template action of CTAB and the co-template action of PEG 400 used to regulate the nucleation and crystal growth are also discussed.

9

Technological and Ecological Aspects of Disposal of Spent Cutting Fluids

100%

Zelenko Y. , Bezovska M. , Kuznetsov V. , Muntian A.

Journal of Ecological Engineering

|

2021

|

tom Vol. 22, nr 4

207--212

EN

Processing of metals by cutting under modern conditions becomes impossible without the use of effective cutting fluids. The main purpose of cutting fluids is cooling, lubrication of the workpiece processing area. Spent emulsion is a special type of wastewater, very dangerous to the environment, as it contains a large number of persistently emulsified petroleum products. The methods using various surfactants were tested for the cutting fluid disposal. The obtained results allowed proposing a general flow diagram of treatment of spent cutting fluids, as well as a block diagram of their purification. After processing the spent cutting fluids according to the proposed diagram, two products were obtained, namely water and sludge. This technology can be used in metalworking shops of railway enterprises, as well as the enterprises of machine-building, metallurgical and other industries where CF-effluents are formed within the wastewater complex. It will provide both an economic result through the reuse of water and will give a significant environmental effect by minimizing the amount of hazardous waste.

10

Wetting properties of the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and polyoxyethylene (23) lauryl ether (Brij 35) binary mixtures in the poly(tetrafluoroethylene)-solution-air system

100%

Krawczyk J.

|

EN

Wettability of poly(tetrafluoroethylene) (PTFE) by aqueous solutions of binary mixtures composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) with polyoxyethylene (23) lauryl ether (Brij 35) was considered on the basis of the measured values of contact angle and surface tension. It was shown that the value of the critical surface tension of PTFE surface wetting at the studied system (23.5 mN/m), does not depend on the concentration and composition of the binary mixtures of studied surfactants in water, and it was higer than the surface tension of PTFE (20.2 mN/m). The best wettability of polytetrafluoroethylene (PTFE) by studied aqueous solutions of binary surfactants mixtures occurs at the mixtures concentration corresponding to the critical micelle concentration of their solutions.

11

Two-step synthesis of high aspect ratio gold nanorods

100%

Mortier T. , Persoons A. , Verbiest T.

Open Chemistry

|

2006

|

tom 4

|

nr 1

160-165

EN

We describe a very simple, two-step synthetic method to prepare gold nanorods with extremely high aspect ratios (> 20) and average lengths of more than 1000 nm. The method is based on a seed-mediated growth in presence of the surfactant cetyltrimethylammonium bromide. The length and aspect ratios of the nanorods can be manipulated by varying the surfactant concentration.

12

Foams Stabilized with Nanoparticles for Gas Well Deliquification

100%

Knapik E. , Stopa J. , Marzec A.

Polish Journal of Chemical Technology

|

2014

|

tom Vol. 16, nr 2

114--117

EN

This study examined the interaction of solid nanoparticles and anionic and non-ionic surfactant at an air–water interface. Aqueous foams stabilized by silica nanoparticles in water with different levels of salinity were studied in detail. The stability of solid/surfactant dispersion was evaluated visually. Nanoparticles content impact and concentration of surfactant on the foamability, deliquification of foams and structure of wet foams were studied. It was found that the foamability of dispersion depends either on the surfactant concentration or on the nanoparticles concentration. The adsorption of hydrophobically modified silica particles and surfactants reduces the air/water interface tension. The results of the examinations showed that the use of nanoparticles allows to increase the efficiency of brine unloading even up to 20%. Surfactant particle and nanosilica present synergistic action, use of 4 wt% of nanoparticles allows to reduce surfactant consumption up to half. The cost of the preparation of the proposed dispersion is slightly higher, about 5%, compared to the sole surfactant.

13

Interaction of polyelectrolyte gels and surface active agents

100%

Zielinska E. , Maslinska-Solich J. , Lekawska E.

Polish Journal of Environmental Studies

|

1999

|

tom 08

|

nr 5

EN

Hydrogel polymers can absorb surface active agents from the water environment, which can be practically applied for their removal from waters polluted with detergents. The carried out investigation studies involved the interaction of maleic anhydride copolymers with vinyl ethers when subjected to crosslinking with various crosslinking agents, as well as generated in Poland cationic, anionic and non-ionic surfactants. A very high absorption of cationic surfactant by the hydrogels has been found, which can be applied in the vicinity of plants using such surfactants, e.g. dairies. Poly(vinyl) alcohol crosslinked with glutaraldehyde, was used as hydrogel too, and it doesn't absorb cationic surfactants.

14

Toxic effect of non-ionic phosphoorganic surfactants on selected organisms representing aquatic biocenosis

100%

Karpinska-Smulikowska J. , Moskal J.

Acta Toxicologica

|

2004

|

tom 12

|

nr 1

15

Surface activity of simple sulfobetaines

88%

Kwasniewska D. , Wieczorek D. , Staszak K.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

|

2015

|

nr 3

16

The effect of sequence of sol-gel multilayer coatings deposition on corrosion behaviour of stainless steel 316L

88%

Chęcmanowski J. G. , Głuszek J. , Masalski J.

Materials Science

|

2003

|

tom Vol. 21, No. 4

387-396

EN

The possibility of producing protective coatings by the sol-gel process is discussed. Metaloorganic complexes open new possibilities for the syntheses of ceramic materials. The most important applications of Si alkoxides for the synthesis of inorganic-inorganic composites are presented. The SiO2 protective coatings on surgical stainless steel 316L have been synthesized by the sol-gel techniques. The multi-layer coatings were deposited by the dip method using sols containing appropriate molar ratios of the prekursor (tetraethoxysilan), anhydrous ethanol, nitric acid and acetic acid. Nanosilica with the surfactant didodecyldimethyl- ammonium bromide were added to the sols applied. Coatings were annealed from 200 st.C to 300 st.C. The electrochemical characterization by dc measurements of the protective coatings in Ringer's solutions is reported. The coatings performance has been compared using polarization characteristics. Two arbitrarily chosen values were taken: the current density at -750 mV and the potential corresponding to the current density of 2 A/cm2. The coatings were chosen and ranked with regard to additional parameters: the polarization resistance and the through-coating porosity. It has been established that the way of applying of the coatings had an influence on the protective properties. The best protective properties have the coatings obtained from sols consisting of three SiO2 layers with nanosilica and three SiO2 layers without nanosilica. The positive effect of nanosilica on the protective properties of the coatings was determinated. Small changes in the preparation process can often have disproportionate large effects on the quality of the coatings.

17

Statistical Optimization of the Preparation of HNIW Nanoparticles via Oil in Water Microemulsions

88%

Bayat Y. , Zarandi M. , Khadiv-Parsi P. , Salimi Beni A.

Central European Journal of Energetic Materials

|

2015

|

tom Vol. 12, no. 3

459--472

EN

HNIW (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) is a family member of high-energy density cage nitramines which have so many versatile applications. In this paper, HNIW nanoparticles were prepared by the oil in water microemulsion route. The effects of various experimental parameters on this reaction were investigated using the Taguchi method. The effects of different variables: organic phase, water/organic phase (W1/W2), organic phase/ propanol (W3/W4) and HNIW weight percent, on the particle size of the HNIW were investigated at three distinct levels. Optimal conditions for obtaining HNIW nanoparticles were determined. Performing the process under the optimal conditions proposed by the Taguchi method leads to the production of HNIW nanoparticles with an average size of about 80 nm. The HNIW nanoparticles were characterized using Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Differential Thermal Analysis (DTA) and X-Ray Diffraction (XRD).

18

The Removal Investigation of Coconut Acid Surfactants in Activated Sludge’s System

88%

Moazzenipour B. , Salehpour A. , Ahansazan B. , Ghorbanian S. , Rashedi H.

Journal of Ecological Engineering

|

2017

|

tom Vol. 18, nr 3

68--73

EN

There are significant municipal concerns relating to the use of surfactants and enzymes in the process of wastewater treatment. Treatment plants use different techniques to remove impurities from water. As wastewater treatment plants use the latest technology to remove contaminants from water, there are high costs, and sometimes an enforcement of regulations is lax. Still, many municipalities across the country prohibit the use of surfactants and enzymes entering wastewater treatment because of the harmful effects of these products on the sewer lines and high damage costs. Surfactant compounds are organic. Their molecules include water-soluble and oil or an insoluble component. These molecular compounds seek the water surface and chemically reduce the boundaries between oil and water. When surfactants are in the water, they absorb into the soil and can cause injury to plants and organic organisms, but people find surfactants and enzymes useful in cleaning agents for emulsifying and dispersing oil and grease. Scientists have found that at least some surfactants are toxic to ecosystems, people and animals, but they have not been able predict far-reaching consequences. And now the most important question is how to solve this problem or how to reduce these negative effects. In this paper we tried to remove surfactants from waste water with an activated sludge system.

19

Spectrophotometric study of interaction and solubilization of procaine hydrochloride in micellar systems

88%

Hosseinzadeh R. , Gheshlagi M. , Tahmasebi R. , Hojjati F.

Open Chemistry

|

2009

|

tom 7

|

nr 1

90-95

EN

The interaction of Procaine hydrochloride (PC) with cationic, anionic and non-ionic surfactants; cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and triton X-100, were investigated. The effect of ionic and non-ionic micelles on solubilization of Procaine in aqueous micellar solution of SDS, CTAB and triton X-100 were studied at pH 6.8 and 29°C using absorption spectrophotometry. By using pseudo-phase model, the partition coefficient between the bulk water and micelles, Kx, was calculated. The results showed that the micelles of CTAB enhanced the solubility of Procaine higher than SDS micelles (Kx = 96 and 166 for SDS and CTAB micelles, respectively) but triton X-100 did not enhanced the solubility of drug because of weak interaction with Procaine. From the resulting binding constant for Procaine-ionic surfactants interactions (Kb = 175 and 128 for SDS and CTAB surfactants, respectively), it was concluded that both electrostatic and hydrophobic interactions affect the interaction of surfactants with cationic procaine. Electrostatic interactions have a great role in the binding and consequently distribution of Procaine in micelle/water phases. These interactions for anionic surfactant (SDS) are higher than for cationic surfactant (CTAB). Gibbs free energy of binding and distribution of procaine between the bulk water and studied surfactant micelles were calculated. [...]

20

Adsorption of poly(acrylic acid) on the surface of TiO2 in the presence of different surfactants

88%

Chibowski S. , Paszkiewicz M. , Patkowski J.

Physicochemical Problems of Mineral Processing

|

2012

|

tom Vol. 48, iss. 1

317-324

EN

Results presented in this paper consider research on the influence of the presence of surfactants (cationic CTAB, anionic SDS) on adsorption of poly(acrylic acid) (PAA) at the titanium dioxide/solution interface. Research was carried out as a function of concentration of surfactants and the way of introduction of reagents to measured mixtures (PAA-CTAB-TiO2-NaCl and PAA-SDS-TiO2-NaCl). In order to compare obtained results of adsorption amount of PAA in mixed systems, measurements of adsorption amount of PAA on titanium dioxide without surfactant addition were also conducted. Observed changes in adsorption amount in the presence of surfactant are a result of an emerging complex polymer-surfactant and competitive adsorption of the two components on the TiO2 surface.