The Adsorption of Polymers Onto Mica: Direct Measurements Using Microbalance and Refractive Index Techniques
Elsevier eBooks, 1983
Publisher Summary This chapter describes the determination of the kinetics of adsorption, and the... more Publisher Summary This chapter describes the determination of the kinetics of adsorption, and the adsorption isotherms of polystyrene adsorbing onto mica from cyclohexane at the θ-temperature (34.5±0.5°C) using the microbalance and refractive index techniques. The adsorption of both PS3 and PS4 from cyclohexane at the θ-temperature onto freshly cleaved mica is rapid, and the plateau value of T at all concentrations is reached at the first measured point on the adsorption vs. time curve. The extent of desorption of PS3 and PS4 is negligible over periods of up to 17 hours. The adsorption of probe beam deflection onto freshly cleaved mica in good solvent conditions is also rapid and appears to be quasi-irreversible. The adsorption isotherm plateau values for PS3 and PS4 are comparable with those determined in ellipsometric and radiometric studies of polystyrene adsorption onto various plane surfaces from cyclohexane under θ-conditions. The adsorbance of PS1 onto the mica surfaces, as determined from refractive index measurements, following 10 hours of incubation is the equilibrium value for the conditions of that study. The adsorbance of polyethylene oxide from aqueous solution onto mica surfaces has been measured using the refractive index approach. The results indicate a considerably higher adsorbance than previously measured for PEO adsorbing onto colloidal silica particles.
Interactions Between Polymer-Bearing Surfaces
Acs Symposium Series, Feb 10, 1984
Les forces agissant entre des surfaces de mica atomiquement polies immergees a la fois dans des m... more Les forces agissant entre des surfaces de mica atomiquement polies immergees a la fois dans des milieux liquides organiques et aqueux sont determinees dans le domaine des separations de surfaces de 0 a 300 nm, a la fois en presence et en absence de couches de polymeres adsorbees
The rheological properties of barite-loaded drilling fluids
Chemical Engineering Research & Design, 1992
Microencapsulation: techniques of formation and characterization
Elsevier eBooks, 1994
The Role of Particle Forces in Determining the Rheological Properties of Concentrated Dispersions. An Experimental Study
Springer eBooks, 1990
The forces of interaction between two mica surfaces bearing an adsorbed layer of a poly-2—vinyl—p... more The forces of interaction between two mica surfaces bearing an adsorbed layer of a poly-2—vinyl—pyridine/polytert—butylstyrene (P2VP/PtBS) AB block copolymer of molecular weight 21 400 has been measured. The forces commence at a surface separation of some 50 nm and increase approximately exponentially with decreasing surface separation. An increase of three orders of magnitude in the force is measured. Subsequently polyacrylonitrile (PAN) particles, stabilised by the same P2VP/PtBS AB block copolymer, have been prepared and the rheological properties of these dispersions determined up to high volume fraction o <0.6. Particular emphasis has been put on the storage modulus of these dispersions, which increases exponentially with increasing o also by three orders of magnitude. The storage modulus should be proportional to the differential of the particle force—distance profile. Using a cellular model the two sets of experimental data may be related and correspondence between the data achieved.
A Nanorheological Study of Adsorbed Polymer Layers
The word stability is ubiquitous in colloid science but means different things to dgferent people... more The word stability is ubiquitous in colloid science but means different things to dgferent people. In a suspension concentrate it is possible to identify three different physical processes which may lead to instability in a particulate system, namely a change in particle size due to Ostwald ripening, particle aggregation and particle sedimentation. Although these processes may occur simultaneously they are here treated separately in order to promote understanding of the physical forces involved.
Coiled-tubing, spud-can and extended reach drilling are amongst the various techniques discussed.... more Coiled-tubing, spud-can and extended reach drilling are amongst the various techniques discussed. Aids to drilling, such as the use of fluids, are covered and various ways of alleviating stuck-pipe, wellbore instability and blowout problems are dealt with. Papers on planning, economics and environmental impacts are also included. (S.J.Stone) 952280 Strategies and structures for drilling and service contracts in the 1990's
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