Three chemical compounds (A1, A2, and A3) with long alkyl chains (C5, C8, and C10) were used in this work to improve the oleophilic and hydrophobic properties of blank flexible polyurethane (FPU) ...cubes for oil spill clean-up. Water sorption was observed to be reduced by almost 50% when compared to blank FPU, while crude oil sorption of modified FPU cubes was raised by A1 = 37.16, A2 = 42.68, and A3 = 45.94 g/g, as well as diesel fuel sorption by A1 = 36.72, A2 = 39.80, and A3 = 41.68 g/g. In the water-oil system, the sorption capacity of FPU cubes modified with three new oleophilic organic compounds was increased by A1 = 43.47, A2 = 44.49, and A3 = 45.15 g/g for crude oil spills and by A1 = 34.07, A2 = 34.16, and A3 = 36.05 g/g for diesel fuel spills, compared to blank FPU cubes of 27.29 and 22.28. The findings suggest that the modified FPU cubes could be utilized to clean up oil spills successfully.
A useful alternative to conventional plastic packaging manufactured from fossil fuels is packaging constructed of a biodegradable polymer. The final qualities of the chitosan cast films heavily ...depend on the type of plasticizer used and how it is incorporated into the chitosan-based material. This work investigates the synthesis of chitosan chemically grafted with succinic acid to improve the physical and mechanical properties of the film. The cortex of local shrimp was used to make a chitosan extract with a molecular weight of 2.702x105 g/mole and a deacetylation level of 80%. The chemically plasticized chitosan film was characterized by FTIR. It was found that chitosan and grafted chitosan film spectra were different from each other, implying the true grafting of succinic acid had occurred and the main backbone of the chitosan structure was unaffected. An examination of the mechanical properties of the films revealed that the results of the tensile strength measurement showed an improvement in the strength and %elongation at break for the chitosan grafted with succinic acid cast film for packaging, which is one of the potential applications for biodegradable chitosan.
Chitosan extracted from shrimp cortex was grafted with some different anhydride compounds like; acetic anhydride, propionic anhydride, succinic anhydride, and phthalic anhydride. The ...chitosan-grafted-anhydrides were copolymerized with L-lactide in ring opening polymerization. All grafted chitosan derivatives were obtained in very good yield, and they were characterized by FTIR and the resulted spectra confirmed the right structures of chitosan and its different synthesized derivatives, and then they were converted to nanoparticles in size by subjecting them to sonication method.In vitro cytotoxicity detection of different chitosan anhydride derivative nanoparticles and their grafted-polylactide were concerning three different types of human breast cancer cell lines as MTT assay, the results exhibit the highly significant cell growth inhibition of these tumor cells compared with a positive control; furthermore, the chitosan anhydride derivatives grafted polylactide demonstrated increasing in reducing cell viability in comparison with their non-grafted form. The DNA fragmentation index percentage was evaluated for some of the studied polymer nanoparticles, using acridine orange dye and the results were shown no or less effective against BT breast carcinoma cell lines DNA
The removal of Congo red dye from aqueous solutions by adsorption reaction onto three distinct adsorbents: graphene oxide (GO), graphene oxide-grafted-3,3’-diaminobenzidine (GO/DAB), and ...GO/DAB-grafted-ethylenediaminetetraacetic acid (GO/DAB/EDTA) was investigated in batch experiments. The study of the effects of pH and contacting time on adsorption systems is the first step in optimizing them. The results revealed that depending on the type of adsorbent, the optimum pH values and periods differed. The Congo red (CR) dye adsorptions onto the investigated adsorbents GO, GO/DAB, and GO/DAB/EDTA required pH (3.0, 7.0, and 5.0, respectively) and time (60, 30, and 45 min). The fundamental adsorption properties of the dye were evaluated using adsorption equilibrium isotherms, namely the Langmuir, Freundlich, and Dubinin–Radushkevich models. The maximum adsorption values (qmax) were calculated using the Langmuir isotherm results, and they were 1,250; 1,428.5 and 1,438.1 mg/g for the adsorption of CR dye onto adsorbents GO, GO/DAB, and GO/DAB/EDTA, respectively, and these results proved the preference for prepared GO-derivatives over GO. The kinetic models, namely pseudo-first-order and pseudo-second-order, were employed to understand the mechanism of the adsorption process, and they fitted very well with the pseudo-second-order kinetic model, which relies on the assumption that chemisorption may be the rate-limiting step. This study reveals that the presence of functional groups and active sites on the studied adsorbent contributed to its high affinity for CR dye adsorption. As a result, they can be used as efficient and cost-effective dye adsorbents in industrial effluent. Thermodynamic parameters including enthalpy ΔH°, entropy ΔS°, free energy ΔG°, and activation energy Ea of the adsorption process were calculated and used to interpret the results, which revealed that the adsorption systems were a spontaneous and endothermic process for GO and its composites. Also, low activation energy values (Ea < 40 kJ/mol) were characteristics of the physisorption mechanism and diffusion-controlled process.
Graphene oxide (GO), graphene oxide/chitosan (GOCS), and graphene oxide/poly(n-butyl meth- acrylate-co-methacrylic acid) (GOpBCM) composites were prepared as adsorbents for removal of carcinogenic ...dye Congo red (CR) from aqueous solutions. They were characterized by various techniques, including Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and X-ray diffraction spectroscopy. Adsorption equilibrium isotherms, adsorption kinetics and thermodynamic studies of the batch adsorption process were done to evaluate the fundamental adsorption properties of the dye CR. The results indicate that the adsorption of CR on the adsorbents was high pH and temperature-dependent. The maximum adsorption of 1,666 mg/g occurred at pH 3.0 for an initial dye concentration of 500.0 mg/L by GOCS, whereas, the maximum adsorption obtained from an initial dye concentration 300.0 mg/L was 1,000 mg/g for GO and GOpBCM at pH 3.0 and 7.0 respectively. The experimental equilibrium adsorption data were explored by three different two-parameter models Langmuir, Freundlich and Temkin isotherms. The Langmuir model was well agreed with experimental data for all adsorbents. The kinetic models, namely pseudo-first-order, pseudo-second-order, and intraparticle-diffusion are employed to understand the mechanism of the adsorption process, and it fitted very well the pseudo-second- order kinetic model for all adsorbents. The calculated thermodynamic parameters revealed that the adsorption is a spontaneous and endothermic process.
The cationic sulfonated polystyrene resin is consumed in the production process of water desalting to produce deionized water used to generate steam boilers in different industries. Our target is to ...reactivate the consumed cationic resin by the grafting process of o-aminobenzoic acid, p-aminobenzoic acid, and acrylamide monomer. The grafting process causes an increasing efficiency of the grafted consumed resin from 54.34% to 55.37%, 56.20%, and 63.22% respectively in removing the boiler’s wastewater hardness. The result of grafted consumed resin with acrylamide is engorging to increase the chain length of acrylamide monomer grafted on the resin by free-radical polymerization using benzoyl peroxide initiator in a dry N2 atmosphere. It increases the efficiency of the consumed resin grafted with polyacrylamide to 83.68%. The same sequence is correct for removing hydrazine used in steam boilers, for metal protection, with efficiency, reaches 100%. Fourier transform infrared spectroscopy confirms evidence of successful grafting processes.
Novel block biocopolymers were made by copolymerizing the prepared polylactide-dipenta-erythritol macromonomer with two different monomers, N-hydroxyethyl acrylamide (HEAA) and N,N-dimethylamino ...ethyl methacrylate (DMAEMA), with an activator generated by atom transfer radical polymerization (ATRP), to have a different duplicating unit of 10, 25, 50, and 100. ATRP employs a copper(I) bromide (CuBr) catalyst system with N, N, N′, N′′, N′′-pentamethyl diethylenetriamine (PMDETA). Different spectroscopic and analytical methods used for characterization of the prepared biocopolymers, such as FT-IR, 1H NMR, 13C NMR, and GPC, showed that they had narrow dispersity with controllable molecular weight and were accompanied by nanostructures as examined by SEM technique on all biocopolymers, confirming the correctness of the expected structures of biocopolymers. The shape and size of the produced polymeric nanoparticles were determined using a scanning electron microscope (SEM), and they were developed using the Image-J application.
Aluminum oxide (ALO) was grafted by acrylic acid monomer (AlO-AM) and then, it was polymerized to produce alumina grafted poly(acrylic acid) (AlO-AP). The prepared AlO-AM and AlO-AP were ...characterized by Fourier-transform infrared, differential scanning calorimetry , thermogravemetric analyzer and particle size distribution. Adsorption equilibrium isotherms, adsorption kinetics and thermodynamic studies of the batch adsorption process were used to examine the fundamental adsorption properties of phenol (P) and p-chlorophenol (PCP). The experimental equilibrium adsorption data were analyzed by three widely used two-parameters Langmuir, Freundlich and Dubinin- Radushkevich isotherms. The maximum P and PCP adsorption capacities based on the Langmuir isotherm were calculated at 56.818, 78.741, 92.593, 80.002, 103.579 and 131.579 mg/g for P and PCP onto ALO, AlO-AM and AlO-AP, respectively. The experimental kinetic data were analyzed by using Pseudo-first order and pseudo-second order kinetic models. A comparison of the kinetic models on the overall adsorption rate showed that the adsorption system can be best described by the pseudo-second order kinetics. Based on the calculated thermodynamic parameters such as enthalpy (ΔH°), entropy (ΔS°) and Gibb’s free energy changes (ΔG°). The negative ΔG° and ΔH° values indicated that the adsorption of P and PCP by AlO-AM and AlO-AP adsorbent was feasible, spontaneous and the process was exothermic in nature.
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