Poly(acrylic acid/Kryptofix 23-Dimethacrylate) superabsorbent polymer [P (AA/Kry23-DM) SAP] was synthesized by solution polymerization to remove Co, Ni, Cu, Cd, Mn, Zn, Pb, Cr, and Fe ions in water and improve the quality of the water. Kry23-DM cross-linker (1,4,7,13,16-Pentaoxa-10,19 diazo cyclohexene icosane di methacrylate) was synthesized using Kry23 and methacryloyl chloride. The characterization of the molecules was done by FTIR, TGA, DSC, and SEM techniques. The effects of parameters such as pH, concentration, and the metal ion interaction on the heavy metal ions uptaking of SAP was investigated. It was observed that P (AA/Kry23-DM) SAP has maximum water absorption, and the absorption increases with the pH increase. Adsorption rates and sorption capacity, desorption ratios, competitive sorption (q_cs), and distribution coefficient (log D) of P(AA/Kry23-DM) SAP were studied as a function of time and pH with the heavy metal ion concentration. Langmuir and Freundlich isotherms of the P (AA/Kry23-DM) SAP were investigated to verify the metal uptake. Molecular mechanic (MM2), Assisted Model Building with Energy Refinement (AMBER), and optimized potentials for liquid simulations (OPLS) methods. were used in quantum chemical calculations for the conformational analysis of the cross-linker and the SAP. ΔH⁰_f calculations of the cross-linker and the superabsorbent were made using Austin Model 1(AM1) method.

Tert-butyl hydroquinone (TBHQ) is a member of the synthetic phenolic antioxidant family that prevents the formation of free radicals and prevents radicals from damaging cells by trapping them. In addition, TBHQ is widely preferred as an additive in foods and vegetable oils because of its low cost and high chemical stability. TBHQ is not only a food preservative but is also frequently used as a stabilizer to prevent auto-polymerization in cosmetics, biodiesel, pharmaceuticals, coating products, and different application areas. TBHQ has been shown to cause diseases, such as DNA damage, carcinogenesis, and cell apoptosis, when administered at high doses. Excessive consumption of TBHQ causes adverse effects, such as stomach tumors, liver damage, and underdevelopment of the reproductive system. Different analytical methods have been used to detect TBHQ in food samples. The most important of these methods are traditional analytical methods such as chromatographic and spectrophotometric methods. However, these methods have basic shortcomings such as high analysis costs, long pre-processing, expensive equipment, need for many organic solvents, requiring expertise, and long detection times. In recent years, electrochemical sensors have attracted attention in the scientific world owing to their high sensitivity, fast analysis time, portability, low cost, and convenience of miniaturization. This review discusses electrochemical studies performed to date for the determination of TBHQ in food samples. The methods used in these studies have been evaluated in a wide range of aspects, such as the electrode, working range, detection limits, and analytical applications.

Syntheses of novel bifunctional poly(methyl methacrylate) (PMMA)-, poly(styrene) (PS)-, and (poly ε-caprolactone) (PCL)-based atom transfer radical polymerization (ATRP) macroinitiators derived from p-xylene-bis(1-hydroxy-3-thia-propanoloxy) core were carried out to obtain ABA-type block copolymers. Firstly, a novel bifunctional ATRP initiator, 1,4-phenylenebis(methylene-thioethane-2,1-diyl)bis(2-bromo-2-methylpropanoat) (PXTBR), synthesized the reaction of p-xylene-bis(1-hydroxy-3-thia-propane) (PXTOH) with α-bromoisobutryl bromide. The PMMA and PS macroinitiators were prepared by ATRP of methyl methacrylate (MMA) and styrene (S) as monomers using (PXTBR) as the initiator and copper(I) bromide/N,N,N′,N″,N″-pentamethyldiethylenetriamine (CuBr/PMDETA) as a catalyst system. Secondly, di(α-bromoester) end-functionalized PCL–based ATRP macronitiator (PXTPCLBr) was prepared by esterification of hydroxyl end groups of PCL-diol (PXTPCLOH) synthesized by Sn(Oct)₂–catalyzed ring opening polymerization (ROP) of ε-CL in bulk using (PXTOH) as initiator. Finally, ABA-type block copolymers, PXT(PS-b-PMMA-b-PS), PXT(PMMA-b-PS-b-PMMA), PXT(PS-b-PCL-b-PS), and PXT(PMMA-b-PCL-b-PMMA), were synthesized by ATRP of MMA and S as monomers using PMMA-, PS-, and PCL-based macroinitiators in the presence of CuBr/PMDETA as the catalyst system in toluene or N,N-dimethylformamide (DMF) at different temperatures. In addition, the extraction abilities of PCL and PS were investigated under liquid–liquid phase conditions using heavy metal picrates (Ag⁺, Cd²⁺, Cu²⁺, Hg²⁺, Pb²⁺, and Zn²⁺) as substrates and measuring with UV-Vis the amounts of picrate in the 1,2–dichloroethane phase before and after treatment with the polymers. The extraction affinity of PXTPCL and PXTPS for Hg²⁺ was found to be highest in the liquid–liquid phase extraction experiments. Characterizations of the molecular structures for synthesized novel initiators, macroinitiators, and the block copolymers were made by spectroscopic (FT–IR, ESI–MS, ¹H NMR, ¹³C NMR), DSC, TGA, chromatographic (GPC), and morphologic SEM.

In this study, a novel PCL-based polymer (6) containing A ₃ B-type zinc phthalocyanine was synthesized as a result of the ring-opening polymerization of ε -caprolactone ( ε -CL), in which A ₃ B-type zinc phthalocyanine (5) prepared by condensation method of two different phthalonitrile precursor molecules, 4-(3-hydroxypropylmercapto)phthalonitrile (3) and 4- tert -butylphthalonitrile (4) , in 3:1 molar ratios used as the initiator. (6) was synthesized in three stages; the synthesis of 4-(3-hydroxypropylmercapto)phthalonitrile (3) (i), novel A ₃ B-type zinc phthalocyanine (ii), PCL-based polymer (6) containing A ₃ B-type zinc phthalocyanine (iii). The novel compounds (5) and (6) were characterized by spectroscopic (FTIR, ¹ H NMR. ¹³ C NMR and UV-vis), DSC and chromatographic (GPC) methods. After that, a new generation hybrid material (PcY-MWCNTP and PcX-MWCNTP) was developed by treating bare Pc (PcX) and polymer-based Pc (PcY) with carboxyl-functionalized multi-walled nanocarbon tube powders (COOH-MWCNTPs). This new nanomaterial was also coated on the glassy carbon electrode (GCE) surface using the drip-dry technique. The sensitivities of the developed both nanosensor in the determination of rifaximin were investigated at first time. Compared to the other electrode, PcX-MWCNTP/GCE significantly increased the anodic signal of rifaximin (approximately 5-fold) and shifted the peak potential to the less positive region. A wide working range from 0.25 mg/L to 10.0 mg/L was obtained, and the limit of detection (LOD) was calculated as 48 µg/L by differential pulse voltammetry (DPV). Finally, the electrochemical method was successfully applied analytically in natural samples to test its accuracy and precision by using PcX-MWCNTP/GCE.

In this study, novel triblock copolymers, including poly(N-isopropylacrylamide)-block-poly(ε-caprolactone)-block-poly(N-isopropylacrylamide) (PNIPAM-b-PCL-b-PNIPAM), poly(N-vinyl-pyrrolidone)-block-poly(ε-caprolactone)-block-poly(N-vinyl-pyrrolidone) (PNVP-b-PCL-b-PNVP), poly(N-isopropylacrylamide-co-N,N-dimethylaminoethyl methacrylate)-block-poly(ε-caprolactone)-block-poly(N-isopropylacrylamide-co-N,N-dimethylaminoethyl methacrylate) (P(DMAEMA-co-NIPAM)-b-PCL-b-P(NIPAM-co-DMAEMA)), and poly(N,N-dimethylacrylamide)-block-poly(ε-caprolactone)-block-poly(N,N-dimethylacrylamide) (PDMA-b-PCL-b-PDMA), were synthesized via a combination of ring-opening polymerization (ROP) and reversible addition–fragmentation chain transfer (RAFT) polymerization. The synthesis was performed using novel bifunctional PCL-based RAFT macro chain transfer agents (macroCTAs; MXTPCL-X1 and MXTPCL-X2) with a m-xylene-bis(2-mercaptoethyloxy) core. Initially, m-xylene-bis(1-hydroxy-3-thia-propane) (MXTOH), which has not previously been used in lactone polymerization, was synthesized via the reaction of α,α′-dibromo-m-xylene with 2-mercaptoethanol in the presence of sodium in ethanol. Subsequently, Sn(Oct)₂-catalyzed ROP of ε-caprolactone (ε-CL) using MXTOH as an initiator yielded PCL-diol (MXTPCLOH). The resulting PCL-diol underwent further functionalization through esterification and substitution reactions, leading to the formation of PCL-based RAFT macroCTAs. Triblock copolymers were synthesized using these macroCTAs with AIBN as an initiator. The synthesized products, along with their intermediates, were characterized using FTIR and ¹H NMR spectroscopy. The number average molecular weight (M_n) and polydispersity index (Ð) of PCL-based macroCTAs were determined by using GPC analysis. The sensor capabilities of the synthesized novel triblock copolymers were investigated on the determination of syringic acid and it was determined that the most sensitive polymer was PNVP-b-PCL-b-PNVP (MXTP2). The working range was between 1.5 µg/mL and 15 µg/mL and the limit of detection (LOD) was found to be 0.44 µg/mL using DPV on MXTP2 polymer sensor.