Ingegärd Johansson | University of Gothenburg (original) (raw)

Papers by Ingegärd Johansson

Research paper thumbnail of Aqueous foams stabilized by n-dodecyl-β-d-maltoside, hexaethyleneglycol monododecyl ether, and their 1 : 1 mixture

Soft Matter, 2009

ABSTRACT Aqueous foams stabilized by the non-ionic surfactants n-dodecyl-b-D-maltoside (b-C 12 G ... more ABSTRACT Aqueous foams stabilized by the non-ionic surfactants n-dodecyl-b-D-maltoside (b-C 12 G 2) and hexaethyleneglycol monododecyl ether (C 12 E 6) as well as by their 1 : 1 mixture were studied as a function of the total surfactant concentration from 0.1 to 10 cmc. Foamability and foam stability were measured with home-built winding equipment, the commercially available FoamScan, and a home-built foam conductivity apparatus (FCA), respectively. It was found that the foamability increases with increasing surfactant concentration for both the single and the mixed surfactant systems. On the other hand, at a fixed relative surfactant concentration (c/cmc) the foamability of b-C 12 G 2 solutions was found to be much higher than that of C 12 E 6 solutions, while the 1 : 1 mixture behaves like the pure C 12 E 6 . Measurements at different gas (N 2) flow rates have shown that the foamability decreases non-linearly with decreasing N 2 flow rate, which shows that foam generation and foam breakdown occur simultaneously. Regarding foam stability it was found that it also increases with increasing surfactant concentration. As was the case for the foamability, the stability of foams stabilized by b-C 12 G 2 was much higher than that of foams stabilized by C 12 E 6 , while the foam stability of the 1 : 1 mixture was comparable to that of the pure C 12 E 6 . The foam results are discussed in the light of static surface tensions, dynamic surface tensions, and surface elasticities, which were measured for the single and the mixed surfactant systems.

Research paper thumbnail of Mixtures of n-dodecyl-β-d-maltoside and hexaoxyethylene dodecyl ether — Surface properties, bulk properties, foam films, and foams

Advances in Colloid and Interface Science, 2010

Mixtures of the two non-ionic surfactants hexaoxyethylene dodecyl ether (C 12 E 6) and n-dodecyl-... more Mixtures of the two non-ionic surfactants hexaoxyethylene dodecyl ether (C 12 E 6) and n-dodecyl-β-D-maltoside (β-C 12 G 2) were studied with regard to surface properties, bulk properties, foam films, and foams. The reason for studying a mixture of an ethylene oxide (C i E j) and a sugar (C n G m) based surfactant is that despite being non-ionic, these two surfactants behave quite differently. Firstly, the physico-chemical properties of aqueous solutions of C n G m surfactants are less temperature-sensitive than those of C i E j solutions. Secondly, the surface charge density q 0 of foam films stabilized by C n G m surfactants is pH insensitive down to the so-called isoelectric point, while that of foam films stabilized by C i E j surfactants changes linearly with the pH. The third difference is related to interaction forces between solid surfaces. Under equilibrium conditions very high forces are needed to expel β-C 12 G 2 from between thiolated gold surfaces, while for C 12 E 6 low loads are sufficient. Fourthly, the adsorption of C 12 E 6 and β-C 12 G 2 on hydrophilic silica and titania, respectively, is inverted. While the surface excess of C 12 E 6 is large on silica and negligible on titania, β-C 12 G 2 adsorbs very little on silica but has a large surface excess on titania. What is the reason for this different behaviour? Under similar conditions and for comparable head group sizes, it was found that the hydration of C i E j surfactants is one order of magnitude higher but on average much weaker than that of C n G m surfactants. Moreover, C n G m surfactants possess a rigid maltoside unit, while C i E j surfactants have a very flexible hydrophilic part. Indeed, most of the different properties mentioned above can be explained by the different hydration and the head group flexibilities. The intriguing question of how mixtures of C i E j and C n G m surfactants would behave arises organically. Thus various properties of C 12 E 6 + β-C 12 G 2 mixtures in aqueous solution have been studied with a focus on the 1:1 mixture. The results are compared with those of the single surfactants and are discussed accordingly.

Research paper thumbnail of Environmentally benign nonionic surfactant systems for use in highly alkaline media

Progress in Colloid and Polymer Science

The increasing use of surfactants has put more and more emphasis on environmental requirements fo... more The increasing use of surfactants has put more and more emphasis on environmental requirements for the chemicals used. It is also important to follow the whole lifetime of the products and to offer possibilities for efficient wastewater treatment. Good cleaning of oily soil from hard surfaces and efficient separation of the oily soil from the wastewater within the same surfactant system is a challenge. In this article a system is described which, by using the specific cloud-point profile that can be achieved when mixing alkyl ethoxylates with alkyl glucosides, offers a possibility to meet that challenge. Alkyl ethoxylates are known to be good wetting agents, emulsifiers and cleaning agents. They are, however, usually not soluble in concentrated electrolytes and/or alkali, which may be needed in the practical use with different water qualities, etc. The more recently developed nonionic surfactant named alkyl glucoside, which has a polyhydroxyl functionality as its hydrophilic part arising from natural sources such as carbohydrates, offers better solubility as well as strong surface activity. When combining these two categories of surfactants good solubility in, for instance, alkali, is achieved and a special concentration-dependent cloud-point curve results. This phenomenon can be used both to fine-tune the cleaning and wetting efficiency and to stimulate the separation of the emulsified oil from the wastewater.

Research paper thumbnail of Thin Film and Foam Properties of Sugar-Based Surfactants

Research paper thumbnail of Nitration of Some 2-Iodo-1,3,5-trialkylbenzenes. Competition between Nitrodeprotonation and Nitrodeiodination. Discussion of Steric Effects

Acta Chemica Scandinavica, 1981

Research paper thumbnail of Use of Mixtures of Alkyl Alkoxylates and Alkyl Glucosides in Strong Electrolytes and Highly Alkaline Systems

Industrial Applications of Surfactants IV, 1999

Research paper thumbnail of Handbook for cleaning/decontamination of surfaces

Volume 1 Physical Aspects of Cleaning Processes (W. von Rybinski). Laundry cleaning of textiles (... more Volume 1 Physical Aspects of Cleaning Processes (W. von Rybinski). Laundry cleaning of textiles (J. Burckett St. Laurent et al.) Formulation of Carpet Cleaners (J. Williams). Dish and Household Cleaning (G. Szewczyk). A review of key ingredients used in Auto-dishwashing formulations past and present and the physico-chemical processes they facilitate. (A. Tomlinson, J. Carnali). Personal Cleansing (Kumar Subramanyan, K.P. Ananthapadmanabhan). Shampoo Formulation (K. Klein, I. Palefsky). Surfactant Action on Skin and Hair: Cleansing and Skin Reactivity Mechanisms (L. Rhein/Sheads). The Cleaning of Teeth (A. Joiner). Dry Cleaning of Textiles (K.D. Hasenclever). Wet Cleaning of Textiles (K.D. Hasenclever). Vehicle Cleaning (Mahnaz Company, D.R Karsa). Back End of Lines (BEOL) cleaning (S. Raghavan et al.). Cleaning of Trace Metallic Impurities From Solid Substrates Using Liquid Media (Dr. S. Verhaverbeke). Elevated Pressure CO2-based Fluids Containing Polar Co-solvents for Cleaning in M...

Research paper thumbnail of Microemulsions in Cosmetics and Detergents

Microemulsions

Page 1. Chapter 8 Microemulsions in Cosmetics and Detergents Wolfgang von Rybinski, Matthias Hlou... more Page 1. Chapter 8 Microemulsions in Cosmetics and Detergents Wolfgang von Rybinski, Matthias Hloucha and Ingeg ¨ard Johansson 8.1 Introduction Products for personal care and home care have to fulfil many different requirements ...

Research paper thumbnail of Nitrodeiodination of Some Alkyl-substituted Iodoanisoles and Iodobenzenes. Discussion of Mechanism

Acta Chemica Scandinavica, 1978

Research paper thumbnail of Nitration of Some 2-Iodo-1,3,5-trialkylbenzenes. Competition between Nitrodeprotonation and Nitrodeiodination. Discussion of Steric Effects

Acta Chemica Scandinavica, 1981

Research paper thumbnail of Nitration of Some 2-Iodo-1,3,5-trialkylbenzenes. Simulation and Discussion of the Kinetics

Acta Chemica Scandinavica, 1981

Research paper thumbnail of Some Medium Effects on the Nitration of 2-Iodo-1,3,5-trineopentylbenzene and 2-Iodo-1,3,5-triisopropylbenzene

Acta Chemica Scandinavica, 1982

Research paper thumbnail of Four Different C 8G 1Alkylglucosides. Anomeric Effects and the Influence of Straight vs Branched Hydrocarbon Chains

Journal of Colloid and Interface Science, 1998

phase behavior (6-14), microemulsions (17), and gen-In this work some of the physical-chemical pr... more phase behavior (6-14), microemulsions (17), and gen-In this work some of the physical-chemical properties of four eral reviews 19). Earlier still, we find articles about the different alkylglucosides are presented. The four alkylglucosides synthesis of AGs. The first real attempt to synthesize AG are 2-ethylhexyl a-D-glucoside, 2-ethylhexyl b-D-glucoside, n-ocsurfactants was performed in 1938 , but as early as tyl a-D-glucoside, and n-octyl b-D-glucoside. Two questions are in 1893, Fisher (21) discussed how to methylate glucose addressed. The first concerns the general influence on surfactant molecules. properties of the type of linkage, a or b, between the glucose head AGs consist of one or several glucose molecules which group and the surfactant tail. The second question concerns the constitute the hydrophilic headgroup and a hydrocarbon difference in properties between straight and branched hydrocarchain that can be either straight or branched, which constibon chains. The binary phase diagrams (temperature vs concentration) and the properties of the one-phase regions have been deter-tutes the hydrophobic tail of the surfactant. The two parts mined. In the micellar regions, 1 H NMR self-diffusion experiments are linked together by a glucosidic linkage (22-24).

Research paper thumbnail of Physical−Chemical Properties of C 9 G 1 and C 10 G 1 β-Alkylglucosides. Phase Diagrams and Aggregate Size/Structure

Research paper thumbnail of Polyhydroxyl-based surfactants and their physico-chemical properties and applications

Current Opinion in Colloid & Interface Science, 1999

Research paper thumbnail of The effect of polymers on the phase behavior of balanced microemulsions: diblock-copolymer and comb-polymers

Colloid and Polymer Science, 2006

The effect of some amphipilic diblock-copolymers and comb-polymers on a balanced Winsor III micro... more The effect of some amphipilic diblock-copolymers and comb-polymers on a balanced Winsor III microemulsion system is investigated with the quaternary system n-octyl-β-d-glucoside/1-octanol/n-octane/D2O as basis system. The diblock-copolymers are polyethyleneoxide-co-polydodecenoxide (PEOx PEDODOy ) and polyethyleneoxide-co-polybutyleneoxide (PEOx PEBUy ), constituted of a straight chain hydrophilic part and a bulky hydrophobic part. Addition of the diblock-copolymer leads to an enhancement of the swelling of the middle phase by uptake of water and oil; a maximum boosting factor of 6 was obtained for PEO111PEDODO25. Nuclear magnetic resonance diffusometry yields the self-diffusion coefficients of all the components in the system. The diffusion experiments provide information on how the microstructure of the bicontinuous microemulsion changes upon addition of the polymers. The reduced self-diffusion coefficients of water and oil are sensitive to the type of polymer that is incorporated in the film. For the diblock-copolymers, as mainly used here, the reduced self-diffusion coefficient of oil and water will respond to how the polymer bends the film. When the film bends away from water, the reduced self-diffusion of the water will increase, whereas the oil diffusion will decrease due to the film acting as a barrier, hindering free diffusion. The self-diffusion coefficient of the polymer and surfactant are similar in magnitude and both decrease slightly with increasing polymer concentration.

Research paper thumbnail of Physical−Chemical Properties of Some Branched Alkyl Glucosides

Langmuir, 1997

... that there are no or little undulations 24,25 in the lamellar structure which can ... A compa... more ... that there are no or little undulations 24,25 in the lamellar structure which can ... A comparison between experimentally obtained self-diffusion coefficients (·) and the prediction (solid line) for ... By means of X-ray diffraction experiments, the liquid crystalline phases have been further ...

Research paper thumbnail of Physical−Chemical Properties of the n Octyl β- d Glucoside/Water System. A Phase Diagram, Self-Diffusion NMR, and SAXS Study

Research paper thumbnail of Foam and Thin-Liquid-Film Studies of Alkyl Glucoside Systems

Langmuir, 1996

The foaming behavior of nonionic alkyl glucosides, in terms of foamability and foam stability, ha... more The foaming behavior of nonionic alkyl glucosides, in terms of foamability and foam stability, has been investigated using various methods. Three different foam tests, two dynamic methods (the Bikerman cylinder and the Watkins funnel) and one static method, have been ...

Research paper thumbnail of Alkyl Glucosides on Hydrophobic Surfaces Studied by Surface Force and Wetting Measurements

Journal of Colloid and Interface Science, 1996

The wetting properties of hydrophobized surfaces in the presadvantage if the surfactant is produc... more The wetting properties of hydrophobized surfaces in the presadvantage if the surfactant is produced from renewable raw ence of alkyl glucosides have been studied using a Wilhelmy balmaterials. Of the most common natural raw materials, carboance technique, and the interparticle forces acting between such hydrates (mainly glucose) have gained renewed interest as surfaces have been investigated using the interferometric surface a source for making environmentally friendly surfactants. It force apparatus. The adsorption at concentrations well below the has been suggested that sugar molecules may replace ethylcmc is rather limited both for the anomerically pure octyl b-glucoene oxide as the polar group and that these nonionic surfacside and for the technical product based on the branched octyl tants could replace ethylene oxide-based surfactants in some glucoside, 2-ethylhexyl glucoside. However, the adsorption results applications. Alkyl glucosides are one of several surfactant in a decreasing surface hydrophobicity, and consequently the force needed to separate two such surfaces from each other is reduced. groups that meet the above demands.

Research paper thumbnail of Aqueous foams stabilized by n-dodecyl-β-d-maltoside, hexaethyleneglycol monododecyl ether, and their 1 : 1 mixture

Soft Matter, 2009

ABSTRACT Aqueous foams stabilized by the non-ionic surfactants n-dodecyl-b-D-maltoside (b-C 12 G ... more ABSTRACT Aqueous foams stabilized by the non-ionic surfactants n-dodecyl-b-D-maltoside (b-C 12 G 2) and hexaethyleneglycol monododecyl ether (C 12 E 6) as well as by their 1 : 1 mixture were studied as a function of the total surfactant concentration from 0.1 to 10 cmc. Foamability and foam stability were measured with home-built winding equipment, the commercially available FoamScan, and a home-built foam conductivity apparatus (FCA), respectively. It was found that the foamability increases with increasing surfactant concentration for both the single and the mixed surfactant systems. On the other hand, at a fixed relative surfactant concentration (c/cmc) the foamability of b-C 12 G 2 solutions was found to be much higher than that of C 12 E 6 solutions, while the 1 : 1 mixture behaves like the pure C 12 E 6 . Measurements at different gas (N 2) flow rates have shown that the foamability decreases non-linearly with decreasing N 2 flow rate, which shows that foam generation and foam breakdown occur simultaneously. Regarding foam stability it was found that it also increases with increasing surfactant concentration. As was the case for the foamability, the stability of foams stabilized by b-C 12 G 2 was much higher than that of foams stabilized by C 12 E 6 , while the foam stability of the 1 : 1 mixture was comparable to that of the pure C 12 E 6 . The foam results are discussed in the light of static surface tensions, dynamic surface tensions, and surface elasticities, which were measured for the single and the mixed surfactant systems.

Research paper thumbnail of Mixtures of n-dodecyl-β-d-maltoside and hexaoxyethylene dodecyl ether — Surface properties, bulk properties, foam films, and foams

Advances in Colloid and Interface Science, 2010

Mixtures of the two non-ionic surfactants hexaoxyethylene dodecyl ether (C 12 E 6) and n-dodecyl-... more Mixtures of the two non-ionic surfactants hexaoxyethylene dodecyl ether (C 12 E 6) and n-dodecyl-β-D-maltoside (β-C 12 G 2) were studied with regard to surface properties, bulk properties, foam films, and foams. The reason for studying a mixture of an ethylene oxide (C i E j) and a sugar (C n G m) based surfactant is that despite being non-ionic, these two surfactants behave quite differently. Firstly, the physico-chemical properties of aqueous solutions of C n G m surfactants are less temperature-sensitive than those of C i E j solutions. Secondly, the surface charge density q 0 of foam films stabilized by C n G m surfactants is pH insensitive down to the so-called isoelectric point, while that of foam films stabilized by C i E j surfactants changes linearly with the pH. The third difference is related to interaction forces between solid surfaces. Under equilibrium conditions very high forces are needed to expel β-C 12 G 2 from between thiolated gold surfaces, while for C 12 E 6 low loads are sufficient. Fourthly, the adsorption of C 12 E 6 and β-C 12 G 2 on hydrophilic silica and titania, respectively, is inverted. While the surface excess of C 12 E 6 is large on silica and negligible on titania, β-C 12 G 2 adsorbs very little on silica but has a large surface excess on titania. What is the reason for this different behaviour? Under similar conditions and for comparable head group sizes, it was found that the hydration of C i E j surfactants is one order of magnitude higher but on average much weaker than that of C n G m surfactants. Moreover, C n G m surfactants possess a rigid maltoside unit, while C i E j surfactants have a very flexible hydrophilic part. Indeed, most of the different properties mentioned above can be explained by the different hydration and the head group flexibilities. The intriguing question of how mixtures of C i E j and C n G m surfactants would behave arises organically. Thus various properties of C 12 E 6 + β-C 12 G 2 mixtures in aqueous solution have been studied with a focus on the 1:1 mixture. The results are compared with those of the single surfactants and are discussed accordingly.

Research paper thumbnail of Environmentally benign nonionic surfactant systems for use in highly alkaline media

Progress in Colloid and Polymer Science

The increasing use of surfactants has put more and more emphasis on environmental requirements fo... more The increasing use of surfactants has put more and more emphasis on environmental requirements for the chemicals used. It is also important to follow the whole lifetime of the products and to offer possibilities for efficient wastewater treatment. Good cleaning of oily soil from hard surfaces and efficient separation of the oily soil from the wastewater within the same surfactant system is a challenge. In this article a system is described which, by using the specific cloud-point profile that can be achieved when mixing alkyl ethoxylates with alkyl glucosides, offers a possibility to meet that challenge. Alkyl ethoxylates are known to be good wetting agents, emulsifiers and cleaning agents. They are, however, usually not soluble in concentrated electrolytes and/or alkali, which may be needed in the practical use with different water qualities, etc. The more recently developed nonionic surfactant named alkyl glucoside, which has a polyhydroxyl functionality as its hydrophilic part arising from natural sources such as carbohydrates, offers better solubility as well as strong surface activity. When combining these two categories of surfactants good solubility in, for instance, alkali, is achieved and a special concentration-dependent cloud-point curve results. This phenomenon can be used both to fine-tune the cleaning and wetting efficiency and to stimulate the separation of the emulsified oil from the wastewater.

Research paper thumbnail of Thin Film and Foam Properties of Sugar-Based Surfactants

Research paper thumbnail of Nitration of Some 2-Iodo-1,3,5-trialkylbenzenes. Competition between Nitrodeprotonation and Nitrodeiodination. Discussion of Steric Effects

Acta Chemica Scandinavica, 1981

Research paper thumbnail of Use of Mixtures of Alkyl Alkoxylates and Alkyl Glucosides in Strong Electrolytes and Highly Alkaline Systems

Industrial Applications of Surfactants IV, 1999

Research paper thumbnail of Handbook for cleaning/decontamination of surfaces

Volume 1 Physical Aspects of Cleaning Processes (W. von Rybinski). Laundry cleaning of textiles (... more Volume 1 Physical Aspects of Cleaning Processes (W. von Rybinski). Laundry cleaning of textiles (J. Burckett St. Laurent et al.) Formulation of Carpet Cleaners (J. Williams). Dish and Household Cleaning (G. Szewczyk). A review of key ingredients used in Auto-dishwashing formulations past and present and the physico-chemical processes they facilitate. (A. Tomlinson, J. Carnali). Personal Cleansing (Kumar Subramanyan, K.P. Ananthapadmanabhan). Shampoo Formulation (K. Klein, I. Palefsky). Surfactant Action on Skin and Hair: Cleansing and Skin Reactivity Mechanisms (L. Rhein/Sheads). The Cleaning of Teeth (A. Joiner). Dry Cleaning of Textiles (K.D. Hasenclever). Wet Cleaning of Textiles (K.D. Hasenclever). Vehicle Cleaning (Mahnaz Company, D.R Karsa). Back End of Lines (BEOL) cleaning (S. Raghavan et al.). Cleaning of Trace Metallic Impurities From Solid Substrates Using Liquid Media (Dr. S. Verhaverbeke). Elevated Pressure CO2-based Fluids Containing Polar Co-solvents for Cleaning in M...

Research paper thumbnail of Microemulsions in Cosmetics and Detergents

Microemulsions

Page 1. Chapter 8 Microemulsions in Cosmetics and Detergents Wolfgang von Rybinski, Matthias Hlou... more Page 1. Chapter 8 Microemulsions in Cosmetics and Detergents Wolfgang von Rybinski, Matthias Hloucha and Ingeg ¨ard Johansson 8.1 Introduction Products for personal care and home care have to fulfil many different requirements ...

Research paper thumbnail of Nitrodeiodination of Some Alkyl-substituted Iodoanisoles and Iodobenzenes. Discussion of Mechanism

Acta Chemica Scandinavica, 1978

Research paper thumbnail of Nitration of Some 2-Iodo-1,3,5-trialkylbenzenes. Competition between Nitrodeprotonation and Nitrodeiodination. Discussion of Steric Effects

Acta Chemica Scandinavica, 1981

Research paper thumbnail of Nitration of Some 2-Iodo-1,3,5-trialkylbenzenes. Simulation and Discussion of the Kinetics

Acta Chemica Scandinavica, 1981

Research paper thumbnail of Some Medium Effects on the Nitration of 2-Iodo-1,3,5-trineopentylbenzene and 2-Iodo-1,3,5-triisopropylbenzene

Acta Chemica Scandinavica, 1982

Research paper thumbnail of Four Different C 8G 1Alkylglucosides. Anomeric Effects and the Influence of Straight vs Branched Hydrocarbon Chains

Journal of Colloid and Interface Science, 1998

phase behavior (6-14), microemulsions (17), and gen-In this work some of the physical-chemical pr... more phase behavior (6-14), microemulsions (17), and gen-In this work some of the physical-chemical properties of four eral reviews 19). Earlier still, we find articles about the different alkylglucosides are presented. The four alkylglucosides synthesis of AGs. The first real attempt to synthesize AG are 2-ethylhexyl a-D-glucoside, 2-ethylhexyl b-D-glucoside, n-ocsurfactants was performed in 1938 , but as early as tyl a-D-glucoside, and n-octyl b-D-glucoside. Two questions are in 1893, Fisher (21) discussed how to methylate glucose addressed. The first concerns the general influence on surfactant molecules. properties of the type of linkage, a or b, between the glucose head AGs consist of one or several glucose molecules which group and the surfactant tail. The second question concerns the constitute the hydrophilic headgroup and a hydrocarbon difference in properties between straight and branched hydrocarchain that can be either straight or branched, which constibon chains. The binary phase diagrams (temperature vs concentration) and the properties of the one-phase regions have been deter-tutes the hydrophobic tail of the surfactant. The two parts mined. In the micellar regions, 1 H NMR self-diffusion experiments are linked together by a glucosidic linkage (22-24).

Research paper thumbnail of Physical−Chemical Properties of C 9 G 1 and C 10 G 1 β-Alkylglucosides. Phase Diagrams and Aggregate Size/Structure

Research paper thumbnail of Polyhydroxyl-based surfactants and their physico-chemical properties and applications

Current Opinion in Colloid & Interface Science, 1999

Research paper thumbnail of The effect of polymers on the phase behavior of balanced microemulsions: diblock-copolymer and comb-polymers

Colloid and Polymer Science, 2006

The effect of some amphipilic diblock-copolymers and comb-polymers on a balanced Winsor III micro... more The effect of some amphipilic diblock-copolymers and comb-polymers on a balanced Winsor III microemulsion system is investigated with the quaternary system n-octyl-β-d-glucoside/1-octanol/n-octane/D2O as basis system. The diblock-copolymers are polyethyleneoxide-co-polydodecenoxide (PEOx PEDODOy ) and polyethyleneoxide-co-polybutyleneoxide (PEOx PEBUy ), constituted of a straight chain hydrophilic part and a bulky hydrophobic part. Addition of the diblock-copolymer leads to an enhancement of the swelling of the middle phase by uptake of water and oil; a maximum boosting factor of 6 was obtained for PEO111PEDODO25. Nuclear magnetic resonance diffusometry yields the self-diffusion coefficients of all the components in the system. The diffusion experiments provide information on how the microstructure of the bicontinuous microemulsion changes upon addition of the polymers. The reduced self-diffusion coefficients of water and oil are sensitive to the type of polymer that is incorporated in the film. For the diblock-copolymers, as mainly used here, the reduced self-diffusion coefficient of oil and water will respond to how the polymer bends the film. When the film bends away from water, the reduced self-diffusion of the water will increase, whereas the oil diffusion will decrease due to the film acting as a barrier, hindering free diffusion. The self-diffusion coefficient of the polymer and surfactant are similar in magnitude and both decrease slightly with increasing polymer concentration.

Research paper thumbnail of Physical−Chemical Properties of Some Branched Alkyl Glucosides

Langmuir, 1997

... that there are no or little undulations 24,25 in the lamellar structure which can ... A compa... more ... that there are no or little undulations 24,25 in the lamellar structure which can ... A comparison between experimentally obtained self-diffusion coefficients (·) and the prediction (solid line) for ... By means of X-ray diffraction experiments, the liquid crystalline phases have been further ...

Research paper thumbnail of Physical−Chemical Properties of the n Octyl β- d Glucoside/Water System. A Phase Diagram, Self-Diffusion NMR, and SAXS Study

Research paper thumbnail of Foam and Thin-Liquid-Film Studies of Alkyl Glucoside Systems

Langmuir, 1996

The foaming behavior of nonionic alkyl glucosides, in terms of foamability and foam stability, ha... more The foaming behavior of nonionic alkyl glucosides, in terms of foamability and foam stability, has been investigated using various methods. Three different foam tests, two dynamic methods (the Bikerman cylinder and the Watkins funnel) and one static method, have been ...

Research paper thumbnail of Alkyl Glucosides on Hydrophobic Surfaces Studied by Surface Force and Wetting Measurements

Journal of Colloid and Interface Science, 1996

The wetting properties of hydrophobized surfaces in the presadvantage if the surfactant is produc... more The wetting properties of hydrophobized surfaces in the presadvantage if the surfactant is produced from renewable raw ence of alkyl glucosides have been studied using a Wilhelmy balmaterials. Of the most common natural raw materials, carboance technique, and the interparticle forces acting between such hydrates (mainly glucose) have gained renewed interest as surfaces have been investigated using the interferometric surface a source for making environmentally friendly surfactants. It force apparatus. The adsorption at concentrations well below the has been suggested that sugar molecules may replace ethylcmc is rather limited both for the anomerically pure octyl b-glucoene oxide as the polar group and that these nonionic surfacside and for the technical product based on the branched octyl tants could replace ethylene oxide-based surfactants in some glucoside, 2-ethylhexyl glucoside. However, the adsorption results applications. Alkyl glucosides are one of several surfactant in a decreasing surface hydrophobicity, and consequently the force needed to separate two such surfaces from each other is reduced. groups that meet the above demands.