Measurement of the dielectric permittivity of colloidal suspensions in the kilohertz frequency range (the so-called low-frequency dielectric dispersion) is a promising tool for the electrokinetic characterization of colloids. However, this technique is less used than would be desirable because of the difficulties associated with the measurements, the most important of which is the electrode pol...

A series of supported phosphotungstic acid (H3PW12O40, HPW) catalysts, including HPW/β, HPW/Sn-β, HPW/H-Y, HPW/H-ZSM-5, HPW/USY, HPW/ReUSY, and HPW/SBA-15, were prepared using an impregnation method for alcoholysis of fructose to ethyl levulinate in ethanol. Among these catalysts, HPW/H-ZSM-5 showed the highest catalytic activity, and the yield of ethyl levulinate from fructose increased with i...

We investigated nano-structural changes of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate-an ionic liquid (IL)-using a small angle X-ray scattering (SAXS) technique over the entire concentration range (0-100 mol %). Fibril structures of cellulose disappeared at 40 mol % of cellulose, which is a significantly higher concentration than the maximum concentration of dissolution (24-28 m...

     Cellulose was applied as a reusable and green catalyst for the facile four-component synthesis of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile derivatives using hydrazine monohydrate, ethyl acetoacetate, malononitrile and aryl aldehydes, under solvent-free and thermal conditions. The use of non-toxic and inexpensive catalyst, short reaction time, clean w...

using ion-exchange resins, a multiple-unit type of oral floating dosage system has been prepared to prolong gastric emptying time of dosage form. the system is composed of beads of drug-resin complex, which are loaded with bicarbonate ions and coated with a hydrophobic polymer. the system is so designed that when the beads reach the stomach, chloride ions are exchanged with bicarbonate and drug...

Microspheres can be tailored to provide targeted and/or sustained release in different parts of the body, including those of eye, nasal cavity, urinary, colon and gastrointestinal tract, thus offering the possibilities of localized as well as systemic controlled release of drugs. Prolonged release of drugs and a reduction in frequency of drug administration can highly improve the patient compli...

Particle and domain sizes strongly influence the properties of materials. Here we present an NMR approach based on paramagnetic relaxation enhancement (PRE) relayed by spin diffusion (SD), which allows us to determine lengths in the nm-μm range. We demonstrate the method on multicomponent organic polymer mixtures by selectively doping one component with a paramagnetic center in order to measure...

the objective of the present study was to develop floating microspheres of cefpodoxime proxetil in order to achieve an extended retention in the upper git, which may result in enhanced absorption and thereby improved bioavailability. the microspheres were prepared by non-aqueous solvent evaporation method using polymers such as hydroxyl propyl methyl cellulose (hpmc k 15 m), ethyl cellulose in ...

Low-cost protein purification methods are in high demand for mass production of low-selling price enzymes that play an important role in the upcoming bioeconomy. A simple protein purification method was developed based on affinity adsorption of a cellulose-binding module-tagged protein on regenerated amorphous cellulose (RAC) followed by modest desorption. The biodegradable cellulosic adsorbent...

Phase separated films with controlled porosity were made from ethyl cellulose (EC) and 30% w/w hydroxypropyl cellulose (HPC). The molecular weight of EC can be used to modify the mass transfer rate through coatings by effects on microstructure of the film. Processing conditions are, however, affected by the solution rheology, which could influence the film quality when using different molecular...