Progress in colloid and polymer science 

About: Progress in colloid and polymer science is an academic journal. The journal publishes majorly in the area(s): Adsorption & Microemulsion. It has an ISSN identifier of 0340-255X. Over the lifetime, 1371 publications have been published receiving 13166 citations.

Comparison of model surfaces for cellulose interactions: elevated pH

Abstract: Two different substrates have been used to measure interaction forces between cellulose and between cellulose and glass at normal and high pH. Forces between microspheres of cellulose (r = 20–30 μm) have been measured using the colloidal probe atomic force microscopy technique. Interactions between Langmuir—Blodgett cellulose films on a hydrophobised mica substrate and a glass sphere have been determined with the noninterferometric surface force apparatus. Also, the interaction between two identical Langmuir—Blodgett cellulose films determined with the interferometric surface force apparatus is given for comparison. At low pH (5.5–6) the interaction at large separations in both systems is characterised by a double-layer repulsion with an electrosteric contribution dominating the shorter-range regime. At pH 10, the Langmuir—Blodgett cellulose film swells considerably, which generates a long-range steric repulsion. In many cases several inward steps have been observed in the force—distance curves. We attribute this to a sudden partial collapse of the swollen cellulose film. After initial compression of the steric layer (upon consecutive force runs) the long-range interaction is again dominated by a double-layer force. In contrast, measurements between two cellulose spheres have shown no excessive swelling. Only a limited increase (from about 10 nm to about 20 nm per surface) of the range of the electrosteric repulsion has been found at pH 10. The force at longer distances is in good agreement with the Poisson—Boltzmann theory, with the surface potential increasing with pH as expected.

Microemulsions ― a qualitative thermodynamic approach

Abstract: Studying the phase diagrams of the binary mixtures thus permits predicting qualitatively the mean temperature of the three-phase body within the pseudoternary phase prism at which one finds the highest efficiency of the amphiphiles with respect to homogenizing equal masses of water and oil

Solvent cast technology – a versatile tool for thin film production

Abstract: The oldest technology in plastic films manufacturing, the continuous solvent cast process, was developed more than hundred years ago driven by the needs of the emerging photographic industry. In the years after 1950, new film extrusion techniques of thermoplastic polymers became the dominant production method for plastic films and the importance of solvent cast technology has declined. Nowadays, the solvent cast technology is becoming increasingly attractive for the production of films with extremely high quality requirements. The advantages of this technology include uniform thickness distribution, maximum optical purity and extremely low haze. The optical orientation is virtually isotropic and the films have excellent flatness and dimensional stability. The cast film can be processed in-line with an optical coating design. The tremendous growth of new liquid crystal display applications has incited the development of new materials and improved processes for solvent casting and coating techniques. The key elements of cast film manufacturing are explained, and technological details are discussed for dope preparation, die design, casting support, film drying and solvent recovery. Main applications of films made by different polymer/solvent combinations are described.

The kinetics of wetting: the dynamic contact angle

Abstract: From measurements of dynamic contact angles, whereby a continuous solid strip is drawn into a large liquid pool, we obtained an operational equation: $$cos\theta _d = cos\theta _o - 2(1 + cos\theta _o )Ca^{1/2}$$ which predicts that under air entrainment conditions, the velocity is independent from the nature of the strip.

Some Thoughts on The Definition of a Gel

Abstract: To avoid the confusion of the concept of a gel frequently encountered in daily markets of food, cosmetics, and other industrial products, the definition of a gel is revisited. Recent proposals of the definition of a gel are overviewed, and classifications of various gels from different points of view are described. Discussion is mainly focused on the gel-sol transition and the difference between the structured liquid and the gel, and the classification of gels by temperature dependence of elastic modulus. Finally, the definition of a gel is proposed as a working hypothesis from rheological and structural view points.