We used statistical mechanics to design polymers that defy conventional wisdom by self-assembling into "megasupramolecules" (≥5000 kg/mol) at low concentration (≤0.3 weight percent). Theoretical treatment of the distribution of individual subunits—end-functional polymers—among cyclic and linear supramolecules (ring-chain equilibrium) predicts that megasupramolecules can form at low total polyme...

the present work reports and discusses the results of a 3d simulation of the injection molding process of a rubber compound that includes the mold flling stage and  material curing, using the computer code is developed in “udf” part of the fluent 6.3 cae software. the data obtained from a rheometer (mdr 2000) is used to characterize the rubber material in order to fnd the cure model parameters ...

High performance liquid chromatography (HPLC) with a size exclusion column and ultraviolet monitoring was used to study the effect of synovial fluid hyaluronate concentration and degree of polymerisation on viscosity and mucin clot formation. Rotational viscometry measurements showed an exponential relation between the synovial fluid hyaluronate concentration and relative viscosity, the viscosi...

We show that a perylene bisimide (PBI)-based gelator forms self-sorted mixtures with a stilbene-based gelator. To form the self-sorted gels, we use a slow pH change induced by the hydrolysis of glucono-δ-lactone (GdL) to gluconic acid. We prove that self-sorting occurs using NMR spectroscopy, UV-Vis spectroscopy, rheology, and viscometry. The corresponding xerogels are photoconductive. Importan...

We have used low shear viscometry and electron microscopy to study the interaction between pure actin filaments and microtubules. Mixtures of microtubules having microtubule-associated proteins (MAPs) with actin filament have very high viscosities compared with the viscosities of the separate components. MAPs themselves also cause a large increase in the viscosity of actin filaments. In contras...

Flow at an air-water interface is limited by drag from both the two-dimensional surface and three-dimensional subphase. Separating these contributions to the interfacial drag is necessary to measure surface viscosity as well as to understand the influence of the interface on flow. In these experiments, a magnetic needle floating on a monolayer-covered air-water interface is put in motion by app...

Non-Newtonian viscosity of blood, i.e., the rise in apparent viscosity at low flow, was believed to be a result of reversible aggregation of red cells at low velocity gradients (shear rate). By making a cone-plate viscometer transparent, direct observation was made possible of the blood flowing under defined shear rates. Red cell aggregates, occurring in all cases at low flow, were reversibly d...

The antioxidative and/or free-radical-scavenging activities of R-()and S-(+)ibuprofen enantiomers, as well as of the drug racemate, were studied in vitro on measuring the kinetics of (uninhibited or drug-inhibited) degradation of high molecular weight hyaluronan by hydroxyl radicals. The continual flux of OH radicals radicals at aerobic conditions was maintained by the H2O2 + Cu 2+ system. The ...