Application of the porous-sphere hydrodynamic model to dilute polymer solutions

The porous-sphere model of Debye–Brinkman–Bueche is applied to predict the limiting frictional coefficient f₀ and intrinsic viscosity [η] of polystyrene fractions in tetrahydrofuran and random protein coils in 6M guanidine hydrochloride. Following the formulation of Wiegel and Mijnlieff, the molecular permeability is modeled to increase exponentially as the square of the distance from the center of the molecule. A method is developed to obtain this permeability from the translational diffusion coefficient. The experimental values of f₀ and [η] are in satisfactory agreement with the calculated values. Also, this analysis predicts values of the Mandelkern–Flory–Scheraga parameter for flexible coils which are significantly smaller than the minimum values permitted by the Kirkwood–Riseman theory. This is in accord with the experimental evidence.     

Decoherence via the dynamical casimir effect

We derive a master equation for a mirror interacting with the vacuum field via radiation pressure. The dynamical Casimir effect leads to decoherence of a superposition state in a time scale that depends on the degree of "macroscopicity" of the state components, and which may be much shorter than the relaxation time scale. Coherent states are selected by the interaction as pointer states.     

EFFECT OF COMPOSITION AND PROCESSING CONDITION ON MICROSTRUCTURAL PROPERTIES AND DURABILITY OF FLUOROPOLYMER/ACRYLIC BLENDS

Fluoropolymer blends have been widely used as binders for exterior coatings because of their excellent resistance to ultra-violet (UV) radiation as well as to many corrosive chemical agents.It is known that the fluorinated component usually has a lower glass transition temperature and easily crystallizes in the final structure depending upon the blend composition and sample annealing condition.We investigated the effect of blend composition and annealing process (slow and fast cooling) on the surface mor...     

Facile Synthesis of Mutagen X (MX): 3-Chloro-4-(dichloromethyl)-5-hydroxy-5H-furan-2-one

3-Chloro-4-(dichloromethyl)-5-hydroxy-5H-furan-2-one (Mutagen X, MX) was synthesized in six steps from commercially-available and inexpensive starting materials (27% overall yield). This synthesis enables the preparation of MX analogs and does not require the use of chlorine gas, as do previously reported methods.     

Synthesis and Characterization of Novel Ferrocenyl-Substituted Pyrroles

The syntheses of new ferrocene substituted pyrroles has been carried out by the reaction of TosMIC with an α, β-unsaturated ferrocene derivative.     

Kinetics of immunoassays with particles as labels: effect of antibody coupling using dendrimers as linkers

In this article, we report on poly(amidoamine) dendrimers (PAMAM) as coupling agents for recombinant single-chain (ScFv) antibodies to nanoparticle (NP) labels, for use in immunoassay. We present a simple theory for the kinetics of particle capture onto a surface by means of an antibody-antigen reaction, in which the important parameter is the fraction of the particle surface that is active for reaction. We describe how increasing the generation number of the linking dendrimers significantly increased the fraction of the NP surface that is active for antigen binding and consequently also increased the assay kinetic rates. Use of dendrimers for conjugation of the NP to the antibody resulted in a significantly higher surface coverage of active antibody, in comparison with mono-valent linker chemistry. As a direct consequence, the increase in effective avidity significantly out-weighed any effect of a decreased diffusion coefficient due to the NP, when compared to that of a molecular dye-labelled antibody. The signal to noise ratio of the G4.5 dendrimer-sensitised nanoparticles out-performed the dye-labelled antibody by approximately four-fold. Particle aggregation experiments with the multi-valent antigen CRP demonstrated reaction-limited aggregation whose rate increased significantly with increasing generation number of the dendrimer linker.     

Enterfernung und Wiedergewinnung von Phenolen aus Industrieabw?ssern mit polymeren Amberlit XAD-Adsorbentien

Ohne Zusammenfassung     

Synthesis and evaluation of a series of novel 2-substituted poly(allylalcohol) side chain liquid crystalline oligomers exhibiting ferroelectricity

Abstract

The recently published Baylis-Hillman methodology has been used to prepare a number of side chain liquid crystalline poly(allylalcohols) incorporating a ferroelectric mesogenic side chain. These poly(allylalcohols) exhibited wide range S?_C phases and, in the case of two of these materials, low glass transition temperatures. The transition temperatures and phase behaviour of the SCLC poly(allylalcohols) were compared to acrylate and methacrylate SCLC oligomers containing a similar mesogenic side chain. The response times for two poly(allylalcohols) exhibiting low glass transition temperatures were also measured over a wide temperature range. Although the poly(allylalcohols) had comparable response times to the analogous acrylate and methacrylate SCLCP, they showed the greater temperature dependence of the response time. However, at 39°C one of the SCLC poly(allylalcohols) showed a response time of 65 ms.