Synthesis of 1-acryloyl-3-phenyl thiourea based pH sensitive hydrogels for removal of samarium and terbium

Development of superabsorbent hydrogel based on Gum Arabic for enhanced removal of anxiolytic drug from water

The growing consumption of anxiolytic drugs like diazepam (DZP) has aggravated the problem of persistent organic pollutants in water. Due to its characteristics, the removal of DZP from water and wastewater is a challenging task. As an effort to deals with this issue, in this study, we report the development of a hydrogel based on Gum Arabic (GA) grafted with poly(acrylic acid) (GA-g-PAAc) to be used in the adsorptive removal of DZP from water. The hydrogel formation was confirmed by Fourier-transform infrared (FTIR) spectroscopy and thermal analysis (TGA/DTG) analyses. Images obtained by scanning electron microscopy (SEM) revealed that GA-g-PAAc hydrogel exhibits a porous morphology while swelling experiments suggest a superabsorbent characteristic (degree of swelling> 600%). From batch experiments, it was found that the removal of DZP reached remarkable percentages (>80%) before 300 min in moderate experimental conditions (pH 7, 25 °C, 150 mg of adsorbent). The adsorption of DZP on GA-g-PAAc followed the pseudo-first order kinetics, and the mechanism was described by the linear Langmuir isotherm. The maximum adsorption capacity (q_max) was calculated to be 15.16 mg g^-1 (at 25 °C), which is comparable or superior to other adsorbent materials used in DZP removal. Reuse experiments showed that GA-g-PAAc keeps appreciable adsorption ability even after five reuse cycles. The results reported here suggest this superabsorbent hydrogel could be a promising adsorbent material to treat water contaminated by anxiolytic drugs, like DZP.

Tragacanth gum-based multifunctional hydrogels and green synthesis of their silver nanocomposites for drug delivery and inactivation of multidrug resistant bacteria

This study investigated natural polymer-based stimuli-responsive hydrogels (TGIAVE) and their silver nanocomposites (TGIAVE-Ag). The hydrogels were composed of tragacanth gum, N-isopropyl acrylamide, and 2-(vinlyoxy) ethanol and were prepared via simple redox polymerization using N,N'-methylene-bis-acrylamide as a crosslinker and potassium persulfate as an initiator. The TGIAVE-Ag were synthesized via a green method involving an aqueous extract of Terminalia bellirica seeds. Structural, thermal, crystallinity, morphology, and size characteristics of the TGIAVE and TGIAVE-Ag were investigated by FTIR, UV-Vis, XRD, DSC, SEM, EDS, DLS, and TEM. To understand the physicochemical interaction and diffusion characteristics of TGIAVEs, network parameters such as zero-order, first-order, Hixson-Crowell, Higuchi, and Korsmeyer-Peppas values were calculated by assessing swelling data. TGIAVE hydrogels at pH 1.2 and 7.4 and temperatures of 25 and 37 °C may be used for time-dependent controlled release of 5-fluorouracil, an anticancer drug, TGIAVE-Ag may be applied for the inactivation of multidrug resistant (MDR) bacteria.