Modification of Superabsorbent Hydrogels for Industrial Wastewater Treatment

A breakthrough in superabsorbent hydrogel (SAH) preparation was studied in the current issue by blending potato starch and acrylic acid for wastewater treatment. Gamma irradiation source (60Co irradiation) was used to irradiate SAH from 1 to 10 kGy dose at room temperature (~27°C). The swelling ratio, water absorption, equilibrium water content, and gel fraction properties of the hydrogel were investigated. The as-prepared hydrogel treated with KOH (THG) showed excellent absorption capacity but less mechanical stability compared to untreated hydrogel (UHG). The gel fraction of treated SAH was slightly lower in methanol, but the utmost in water at 5 kGy infers the proper grafting of SAH at this point. The prepared SAH was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) to investigate the surface morphology and molecular interaction, respectively. Moreover, this study’s focal point is to propose an alternative method to remove chromium and methylene blue by SAH from industrial wastewater. The Cr adsorption capacity of UHG was higher than that of THG because the proton’s replacement is easier than that of K by Cr. On the other hand, THG was found to be more efficient in removing methylene blue from industrial wastewater due to the presence of an easily ionized group (–COOK) in SAH. Therefore, the hydrogel can be proposed as a potential superabsorbent to remove heavy metals and organic dyes from industrial wastewater.

Amino Acid Oligomer Microspheres as Drug Delivery Systems. II. Oligomerization of NCAs Initiated with L-Tyrosine Methyl Ester

Oligomerizations of various amino acid N-carboxyanhydrides (NCAs) were prepared in the presence of L-tyrosine methyl ester (Tyr.Me). Tyr.Me was found to be an efficient initiator to form oligopeptides consisting of L-aspartic acid, L-glutamic acid, L-phenylalanine, and L-tyrosine with random arrangements of amino acids. In acidic solution, the oligopeptides formed microspheres which were capable of encapsulating macromolecular drugs such as insulin and heparin. These microspheres were considered to be potential oral drug delivery systems.

A green approach to crosslinked polymer microspheres with undoped methacrylate monomers and their potential application as dental restorative materials

Pure polymer microspheres with undoped methacrylate monomers were prepared and firstly applied as organic fillers for dental restorative materials.

Effect of poly(ethylene oxide) on the release behaviors of poly(ɛ-caprolactone) microcapsules containing erythromycin

The biodegradable poly(epsilon-caprolactone) (PCL)/poly(ethylene oxide) (PEO) microcapsules and the analyzing of form and features for the manufacturing conditions were investigated in a prospective drug delivery systems (DDS) through drug release. The effects of emulsifier, emulsifier concentration, and stirring rate on the diameter and form of the microcapsules were examined using image analyzer (IA) and scanning electron microscope (SEM). The role of interfacial adhesion between PCL/PEO and drug was determined by contact angle measurements, and the drug release rate of the microcapsules was characterized by UV-vis spectroscopy. As a result, the microcapsules were made in spherical forms with a mean particle size of 170 nm approximately 68 microm. And the work of adhesion between water and PCL/PEO was increased with increasing the PEO content, which is due to higher hydrophilicity of PEO. The drug release rate of the microcapsules was significantly increased as the PEO content increased, which could be attributed to the increasing of the hydrophilic groups or the degree of adhesion at the interfaces.

Acrylic polymeric nanospheres for the release and recognition of molecules of clinical interest

Cross-linked poly(methylmethacrylate-co-methacrylic acid) nanospheres were imprinted with theophylline through template radical polymerisation in diluted acetonitrile solution. This study will focus on the effect of functional monomer nature used (methylmethacrylate and/or methacrylic acid) in the recognition and in the release of template in order to develop a material with combined properties of drug delivery and rebinding for clinical applications. After template extraction the nanospheres showed satisfactory recognition properties (up to 1mg template/g of polymer). Moreover polymers prepared selectively removed theophylline with a theophylline rebinding of 5.1 times higher than that of caffeine, a compound of similar structure. Drug release properties were also satisfactory (up to 95% of loaded theophylline in 7 days).

Preparation and characterization of biodegradable poly(l-lactide)/poly(ethylene glycol) microcapsules containing erythromycin by emulsion solvent evaporation technique

In this work, the producing of a biodegradable poly(l-lactide) (PLA)/poly(ethylene glycol) (PEG) microcapsule by emulsion solvent evaporation method was investigated. The effect of PEG segments added to the PLA microcapsules on the degradation, size distribution, and release behavior was studied. According to the results, PLA/PEG copolymer was more hydrophilic than PLA homopolymer, and with lower glass transition temperature. The surface of PLA/PEG microcapsules was not as smooth as that of PLA microcapsules, the mean diameters of prepared PLA and PLA/PEG microcapsules were 40 and 57 microm, respectively. And spherical forms were observed by the image analyzer and the scanning electron microscope (SEM). Drug release from microcapsules was affected by the properties of PLA/PEG copolymers determined by UV-vis spectra. It was found that the drug release rates of the microcapsules were significantly increased with adding of PEG, which explained by increasing hydrophilic groups.

Formation of Monodisperse Polyacrylamide Particles by Radiation-Induced Dispersion Polymerization: Particle Size and Size Distribution

Polyacrylamide microparticles were directly produced by radiation-induced dispersion polymerization in aqueous alcohol media using poly(N-vinylpyrrolidone) as a steric stabilizer at room temperature. The hydrodynamic diameter of a polymer particle and its distribution were measured on a dynamic laser light-scattering spectrometer. This method takes advantages of the specialties of radiation induction, and highly uniform polymer microspheres were obtained with high conversion. The number of the particle produced in the early stage of the polymerization was found to be constant during the remainder of the polymerization. The effects of various polymerization parameters, such as absorbed dose rate, monomer concentration, stabilizer content, medium polarity, and polymerization temperature on the particle size and size distribution were systematically investigated.