In the present study، hydrogels were prepared by free radical polymerization in water–dioxane mixture with fixed molar ratio (25 mol%) of N-isopropyl ACRYLAMIDE (NIPAM) and varying remaining molar concentrations of N-tert-butyl ACRYLAMIDE (NTBA) and ACRYLAMIDE (AAm). The structure of the resultant hydrogels was studied by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The thermal properties of the hydrogels were analyzed by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. DSC thermo grams were used for the quantitative determination of free، interfacial and bound water contents. The result showed that the free and interfacial water contents increased with increase in the hydrophilic AAm content، and the bound water content increased with hydrophobic NTBA content in the hydrogels. Swelling behavior of the hydrogels was evaluated at different temperatures. The percentage swelling and diffusion kinetic parameters (network structure constant, type of diffusion and diffusion constant) were calculated for all samples. The diffusion was found to be Fickian type for copolymer having equimolar concentrations of NTBA and AAm and non-Fickian type for others. Diffusion coefficients of the hydrogels were found to be increased with increasing temperature. In addition, poly (NIPAM-co-NTBA-co-AAm) hydrogels were used in concentration separation process for BSA solution. The result showed that the copolymer with equimolar NTBA and AAm contents has high separation efficiency with good thermo responsive behavior among all copolymers.

Objective(s): Physiological changes in the body may be utilized as potential triggers for controlled drug delivery. Based on these mechanisms, stimulus-responsive drug delivery has been developed.Materials and Methods: In this study, a kind of poly (N-isopropyl ACRYLAMIDE-ACRYLAMIDE) membrane was prepared by radical copolymerization. Changes in swelling ratios and diameters of the membrane were investigated in terms of temperature. On-off regulation of drug permeation through the membrane was then studied at temperatures below and above the phase transition temperature of the membrane. Two drugs, vitamin B12 and acetaminophen were chosen as models of high and low molecular weights here, respectively.Results: It was indicated that at temperatures below the phase transition temperature of the membrane, copolymer was in a swollen state. Above the phase transition temperature, water was partially expelled from the functional groups of the copolymer. Permeation of high molecular weight drug models such as vitamin B12 was shown to be much more distinct at temperatures below the phase transition temperature when the copolymer was in a swollen state. At higher temperatures when the copolymer was shrunken, drug permeation through the membrane was substantially decreased. However for acetaminophen, such a big change in drug permeation around the phase transition temperature of the membrane was not observed.Conclusion: According to the pore mechanism of drug transport through hydrogels, permeability of solutes decreased with increasing molecular size. As a result, the relative permeability, around the phase transition temperature of the copolymer, was higher for solutes of high molecular weight.

ACRYLAMIDE was polymerized at 40 and 80 degrees C in presence of 4,4"-azobis-4cyanovaleric acid by radical polymerization, to high conversions. The polyACRYLAMIDEs were isolated by precipitation in methanol. After drying, the limiting viscosity numbers, [eta], and apparent molecular weights of polyACRYLAMIDEs were determined viscometrically by several empirical equations, in distilled water and also by GPC. The dependence of limiting viscosity number on percentage conversion is discussed, and the significance of polymer branching at 40 and 80 degrees C is assessed.

Today, fabrication of complex-shaped ceramic parts in large quantities has been limited to the processes required extensive and expensive machining (i.e., injection moulding or pressure slip casting). These technologies for shaping ceramics, however, possess several shortcomings that limit their use as a complex-shape forming method. Because of these limitations “gel-casting” which was lacking in above deficiencies, has been proposed as a general and desired method for shaping any ceramic powder. In this work, gel-casting of ?-alumina is investigated based on in situ polymerization and gelation of ACRYLAMIDE monomers as the setting mechanism for forming the green part. Special attention was paid to the preparation of fluid, castable slurries with a high loading of α-Al2O4 (>80 wt.%) and low viscosity (0.65 Pa.s) by using polyelectrolyte dispersants (i.e., poly(methacrylic acid salts), also gelation of ACRYLAMIDE (effect of gelation factors on idle time), mould materials, drying of parts through the liquid desiccant drying method and its comparison with conventional drying technique, green machining, debinding and si