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In this study, poly(n-isopropylacrylamide) (PNIPA) has been synthesized by the free-radical polymerization method using azobisisobutyronitrile the initiator. Then, nanoparticle-PNIPA composite is prepared with magnetic iron oxide (Fe3O4) nanoparticles synthesized by co-precipitation. The thermal decomposition kinetics of synthesized PNIPA and nanocoated PNIPA have been investigated. It has been observed that nanocoated PNIPA has a more stable structure at high temperatures than synthesized PNIPA. In the newly improved model equations relate to thermal decomposition kinetics, a special solution has been made with the new approach. Moreover, the calculated activation energies of the samples have been evaluated with response surface methodology (RSM). The ratios required to synthesize nanocoated-PNIPA under the optimum conditions have been determined by RSM. The activation energy of the nanocomposite obtains when 0.3170 g PNIPA is coated with 0.048 g Fe3O4 nanoparticle is determined as 127.757 kJ/mol. In other words, nanocoating has been increased the thermal stability of the synthesized composite. Poly (n-isopropylacrylamide) has been synthesized by free radical polymerization The Fe-O stretching vibration proves the existence of nanoparticle in FTIR spectra The thermal decomposition kinetics of synthesized PNIPA and Fe3O4-PNIPA nanocomposite have been evaluated by RSM. Magnetic nanoparticle reinforcement enhances the thermal stability of PNIPA [ABSTRACT FROM AUTHOR]

Spent hydrodesulfurization catalyst (HDS) is considered as the important secondary resource for Mo and Ni. The separation of Mo from HDS was usually conducted by soda roasting and water leaching, while Ni remained in the leached residue. This study proposed a method to recover Ni from leached residue by H2SO4 leaching and solvent extraction, and Ni was recycled in the form of NiO. The results showed that the optimum Ni leaching process were conducted using 30% H2SO4 with liquid–solid ratio of 10 at 70 ℃ for 120 min. The optimal extraction was accomplished using 30% di-(2-ethylhexyl) phosphate (P204) saponification at pH value 6.0 with organic/aqueous (O/A ratio) of 1 for 1 min. Additionally, 20% H2SO4 could be used to strip Ni from organic phase with O/A ratio of 10. Finally, NiSO4 was calcined at 850 ℃ for 1.0 h to obtain NiO. The Ni leaching kinetic analysis showed that the activation energy of Ni leaching process was 16.10 kJ/mol, which was accorded with the shrinkage unreacted kernel model controlled by internal diffusion. This study provided an alternative method to recycle Ni and given a deeper insight to the leaching mechanism during H2SO4 leaching Ni from spent catalyst. [ABSTRACT FROM AUTHOR]

In this research, hollow inorganic microsphere (Q-cel) reinforced unsaturated polyester composite is produced, and its thermophysical properties have been characterized. The thermal decomposition kinetics of the composite obtained at different heating rates and various compositions are modeled using artificial neural networks. Also, the production optimization of the polyester composite has been evaluated using response surface methodology. The study has been repeated for certain heating rates (5, 10, and 20 K/min). Activation energies of polyester composites have been calculated using thermogravimetric data and kinetic methods. Changes in activation energy during the thermal decomposition (4 wt.% Q-cel, 94 wt.% UP, 580–660 K, and 20 K/min) of the composite are compared using FWO (129.4 kJ/mol), KAS (127.6 kJ/mol), and CR (126.5 kJ/mol). According to the results, it is seen that the activation energy goes up as the temperature and Q-cel ratio by the mass increase. When the amount of the filler in the polyester composite increases, the thermal conductivity coefficient also rises. As well as, it is determined that as Q-cel ratio in the mixture raises, the density of the composite decreases and Shore D hardness goes up. A new and original composite has been produced with Qcel-reinforced unsaturated polyester. The density of the composite is low, its thermal stability is high, and its easy processability will provide a great convenience. Modeling the Qcel ratio of the composite with RSM and the activation energy with ANN have been provided fast, efficient and optimum results. With the composite obtained, both lightweight and thermally stable polymer materials will be produced. [ABSTRACT FROM AUTHOR]

The development of fertilizer technology is directed towards the production and application of slow or controlled fertilizers. In order to prevent these losses and difficulties, slow and controlled release fertilizers can be produced. Slow or controlled release fertilizers are fertilizers that can be in organic or inorganic form, in solid or liquid form, release the nutrients they contain more slowly than conventional fertilizers, depending on water dissolution, microbial decomposition, growing environment conditions, and thus provide a longer lasting effect. Thus, it is possible to provide the plant with the necessary plant nutrients during the growth period. In this study, three different elements were bound to sugar beet pulp modified with citric acid and their dissolution tendencies were investigated in different environments from the material to which the elements were attached. The dissolution trends were chosen to reflect the natural medium as best as possible. The best dissolution tendencies for all 3 elements were realized in percolations made with EDTA solutions. After the EDTA solution, the dissolution tendencies obtained in the study are followed by citric acid solution, humic acid solution, buffer solution, tap water, and pure water, respectively. The media that best represent the soil solution are tap water, humic acid, and citric acid solutions. Therefore, these two environments are of great importance for the study. It was determined that the modified sugar beet pulp binds these metal ions at the rate of 108.2, 87.1, and 45.7 mg/g, respectively, by contacting with Cu2+, Zn2+, and Mn2+ solutions for 24 h. The dissolution tendencies of this metal-bound bonded material in different environments were investigated. After the EDTA solution, the dissolution tendencies obtained in the study are followed by citric acid solution, humic acid solution, buffer solution, tap water, and pure water, respectively. The media that best represent the soil solution are tap water, humic acid, and citric acid solutions. Therefore, these two environments are of great importance for the study. In the light of these results, it has been shown that modified sugar beet pulp with copper, zinc, and manganese binding can be used effectively as a slow dissolving micronutrient fertilizer in soils with trace element deficiency. [ABSTRACT FROM AUTHOR]