Hydrogels are formed when a three‐dimensional polymeric network is loosely crosslinked. They are swollen by water but not dissolved in it. Hydrogels may display reversible sol–gel transitions, induced by changes in the environmental conditions such as temperature, pH, ionic strength, phase separation, wave length of light, crystallinity, etc. Hydrogel is described as smart or intelligent when sharp transition is induced by small change in such conditions. For the shape‐memory hydrogels, reversible change in shape may also be induced by such stimuli. The preparation and applications of the molecularly imprinted polymeric hydrogels (MIPs) are illustrated by a few examples. The use of shape sensitive hydrogels in microfluidic is mentioned. Application of hydrogels for chronobiology and chronotherapy is outlined. The conversion of hydrogels into aerogels and their respective properties is discussed. Copyright © 2009 John Wiley & Sons, Ltd.

Recently investigated applications of polymeric materials for tissue engineering, regenerative medicine, implants, stents, and medical devices are described in the present review. Papers published during the last 2 years about polymeric materials used for preparation of various polymeric scaffolds, methods of fabrication of such scaffolds and their effectiveness in providing support for cell growth and development into various tissues and enhancing or mimicking an extracellular network (ECM's) have been cited. Papers describing the use of such polymeric materials for tissue engineering of cartilage and bones were cited. The exciting developments in the field of regenerative medicine, based on application of the self‐assembled biocompatible polymeric scaffolds for regeneration of tissues and organs are described in some detail. The use of the biocompatible and biodegradable collapsible polymeric stents, as well as the use of biocompatible, but not necessarily biodegradable polymeric materials for protective coatings of metallic stents and reservoirs of drugs, preventing restenosis and other post‐operative complications that may occur after insertion of a stent, have been reviewed. Clinical results pointing out the advantages of such treatments, as well as results indicating their limitations, have been cited. New formulas, for coating implants, stents, and other medical devices, have been discussed. Copyright © 2006 John Wiley & Sons, Ltd.

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A concise review of papers published during the last 3 years about the synthesis, blends, processing, and applications of electronically conductive polymers, is presented in this article. Copyright © 2002 John Wiley & Sons, Ltd.

Experimental data on solid particle velocities were obtained from a 5 cm i.d. Schildknecht-type column by using model systems. The variables tested were the helix angular speed, the solid concentration, the particle diameter, and the viscosity of the supporting fluid. Two transport regimes were observed depending on the ratio Vx/Vn, where Vx is the particle free-settling velocity and Vn the apparent downward helix velocity. For both regimes, data were correlated by using a velocity equation. For Vx > l/n, the experimental data fit a correlation reported in the literature if suitable frictional coefficients are inserted. For l/t < l/n, an empirical correlation has been developed to describe quantitatively the crystals axial velocity which takes into account the helix speed and the system's physical and transport properties.

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SynopsisSoluble chloromethylated polystyrene and its copolymers with vinylidene chloride as well as poly(pheny1 oxides) brominated in the side chains and in the ring were synthesized and characterized in detail by NMR. The halogenated polymers were phosphonylated with alkyl phosphites. Uncrosslinked polymers with pendent phosphonate groups were prepared in the presence of etheral solvents, which solvate the ionic intermediates of the Arbuzov reaction. These polyphosphonates are highly hygroscopic and are soluble in a variety of solvents. Their 2';s are in the range of 50-175OC. Their thermal behavior was analyzed on the basis of thermogravimetric measurements combined with mass-spectrometric analysis. Poly(styrene phosphonate) seems to be the most stable, and its thermal decomposition starts at -330°C. The polymeric phosphonates are compatible with an unusually large number of polymeric systems and seem to form "true" polymeric alloys with acetylcellulose.

Diphenylacetylene (DPA) reacts instantly with sodium biphenylide (B• ™,Na+) in hexamethylphosphoramide (HMPA) and forms the radical ions DPA -. No further reduction takes place in HMPA even if B • -is in excess.