Allan Twynam BP Sunbury, England For help in preparation of this article, thanks to Curtis Boney, Ernie Brown, Steve Davies and George Hawkins, Sugar Land, Texas, USA; Jorge Gonzalez and Arthur Milne, Caracas, Venezuela; Satyaki Ray, Calgary, Alberta, Canada; and David Schoderbek, Burlington Resources Canada, Calgary. ClearFRAC, ClearPAC, CoalFRAC, FMI (Fullbore Formation MicroImager), FracCADE...

Micrometer sized capsules are often used as single entities for the encapsulation and release of active ingredients, example in food, cosmetics, drug delivery. Important parameters that determine stability reagents contained them dimensions composition their shell. Most capsule shells rather thick, thereby occupying a significant fraction volume, or they rigid, making fragile. This work introdu...

Understanding the numerous factors that can affect biofilm formation and stability remain poorly understood. One of the major limitations is the accurate measurement of biofilm stability and cohesiveness in real-time when exposed to changing environmental conditions. Here we present a novel method to measure biofilm strength: interfacial rheology. By culturing a range of bacterial biofilms on a...

The effect of dilute, insoluble surfactant on the deformation and breakup of a viscous drop is examined. Two cases are considered: the deformation and stretching of a drop in a uniaxial extensional flow and the surface-tension-driven motion of an elongated drop in a quiescent fluid. Aside from resealing the mean capillary force through an average decrease in the interfacial tension, surfactants...

We have studied the rheological properties of mixtures of polyoxyethylene (10 mol) phytosterol (PhyEO(10)) and polyoxyethylene (10 mol) cholesterol (ChEO(10)) mixed in different ratios along with tetraethylene glycol monododecyl ether (C(12)EO(4)) surfactants in water. Addition of C(12)EO(4) to the aqueous solution of a mixture of (PhyEO(10) + ChEO(10)) results in one-dimensional micellar growt...

Surface light scattering (SLS) by capillary waves was used to investigate the adsorption behavior of non-ionic sugar surfactants at the air/liquid interface. SLS by the subphase (water) followed predictions from hydrodynamic theory. The viscoelastic properties (surface elasticity and surface viscosity) of monolayers formed by octyl beta-glucoside, octyl alpha-glucoside, and 2-ethylhexyl alpha-g...

It is well known that there are wide varieties of materials which form self-organized structure. When a sort of 3 dimensional network structure is formed, the system may possess viscoelastic properties similar to entangled polymers or gels depending on life time and strength of the structure. A typical example of low molecular weight system is wormlike micelles formed in aqueous solutions of su...