APPLIED RESEARCH IN CHEMICAL POLYMER ENGINEERING
Year:2019 | Volume:2 | Issue:4 |Papers Count:6

Gel treatment is one of the most promising remedy methods to improve conformance in heterogeneous reservoirs for better sweep efficiency. In this paper, new enhanced preformed particle gels (PPGs) for conformance control at the Balal reservoir are introduced. In these PPGs, three species of 2-acrylamido-2-methylpropane sulfonic sodium salt (AMPSNa), acrylamide (AM) and N-vinylpyrrolidone (NVP) monomers have been used to synthesize via free radical crosslinking polymerization at room temperature using N, N-methylenebis (acrylamide) (MBA) as a cross linker. The swelling properties of the PPGs were enhanced by adding the Nano clay Montmorillonite Na+. A temperature stability agent was also used to make these special PPGs compatible with high temperature and salinity reservoir conditions. Then, PPGs were kept in Balal reservoir conditions in order to study their stability in harsh reservoir conditions. To this end, combination of 50 samples of the preformed particle gel has already been constructed by design of experiment using response surface method, and finally a new model for predicting the swelling ratio of the preformed particle gel based on the weight percentage of material and in different salinity is provided. The results of this research show that the crosslink has more influence on the swelling ratio, and PPG with the optimal formulation will able to guarantee the hard reservoir conditions (temperature 82˚ C & salinity 260000ppm).

In this study, phenolic compounds-coated ZnO@HAP nanocomposite (Ph. ZnO@HAP) was synthesized and used to improve the physical and chemical properties of chitosan hydrogel for biological application. At first, the phenolic compounds were extracted from walnut green hulls. The synthesis of Ph. ZnO@HAP nanocomposite was performed with the assistance of extracted phenols using a hydrothermal method. Chitosan hydrogel was also prepared using NaHCO3 at 37° C. Hybrid hydrogels based on chitosan and Ph. ZnO@HAP nanocomposite were prepared in a similar way and then characterized by fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The antioxidant property, cytotoxicity, and osteogenesis of hybrid hydrogels were measured using DPPH radical scavenging method, MTT, and alkaline phosphatase enzyme assay, respectively. The FTIR spectra, FESEM images, EDX spectrum, and Zeta potential data showed that Ph. ZnO@HAP nanocomposites synthesized successfully with rod-like morphology, phenolic compounds coated on the surface and a negative particle surface charge. The results of DPPH experiment showed that the antioxidant property of the nanocomposite material increased in a concentration-dependent manner. The FESEM images of chitosan hybrid hydrogels with different concentrations of embedded Ph. ZnO@HAP nanocomposite showed that hybrid hydrogels have a more uniform porous structure, compared to the chitosan hydrogel. Moreover, by an increase in the nanocomposite concentration in the structure of hybrid hydrogels, the antioxidant property augmented. The results of the biological studies showed that the cytotoxicity of hybrid hydrogels on osteoblast-like cells (Saos-2) is lower than that of chitosan hydrogel. Also, hybrid hydrogels showed the higher potential in induction of osteogenesis than chitosan hydrogels.

In this study, sonochemical synthesis was used to prepare nanostructured HZSM-5 catalysts. The three most effective ultrasound related variables including ultrasound power, irradiation time, and sonication temperature were investigated. The combined effect of these variables on relative crystallinity and mean crystal size of HZSM-5 nanocatalysts was studied using a central composite design. Higher crystallinity and lower crystal size were obtained by increasing ultrasound power, irradiation time, and sonication temperature while there was an optimum range for mentioned variables. The maximum relative crystallinity and minimum mean crystal size were obtained as 55. 51% and 62. 37 nm, respectively, under the optimal conditions of ultrasound power (231 W), irradiation time (21. 18 min), and sonication temperature (42. 68 ° C). The results confirmed that sonochemical method considerably increased crysatllinity and reduced crystal size of HZSM-5 nanocatalysts at lower time. Hydrothermal method produced catalyst with full crystallinity and mean crystal size of 893 nm with 120 min aging and 48 h crystallization in autoclave while sonicated HZSM-5 catalyst with 21 min sonication and 4 h crystallization has 55. 51% crystllinity and 62. 37 nm mean crystal size. On the other hand, no HZSM-5 phase was formed in hydrothermal method with 120 min aging and 4 h crystallization in autoclave. These results strongly suggests that a catalyst with smaller crystal size, higher crystallinity and BET surface area at lower crystallization time can be obtained by using ultrasound instead of aging step in HZSM-5 synthesis.

The current study is based on synthesis a low cost carbon aerogel with improved properties and thermal insulator approach. In this work cheap novolac resin are used as a raw material for producing polymer aerogel by ambient drying method; then the coal tar pitch is added to samples by immerging them in pitch solution. In next step novolac-pitch polymer aerogels is converted to carbon nano-structure aerogels by pyrolysis heat treatment at inert atmosphere. The results proved, nano-structured aerogels with predictable density will be achieved by this method; also by studying on microstructure and morphology of aerogels it founded these aerogels have high porosity, low density(about 0. 1-0. 4 g/cm3) and high specific surface area (about 600 m2/g). The charring pitch was a lot and using of it made improved thermal properties that resulted in at least 100s delay in increasing temperature in time-temperature history test; as a result a high performance thermal insulator achieved.

Dehydrogenation of alkane to alkene is a key process in petrochemical industry. Propylene has intermediate role to production many industrial polymers. In this research applying oxidative dehydrogenation method for propylene production and CO2 used as oxidant. By use of XRD, Raman, TEM, BET and EDX techniques the results have been analyzed. In XRD and Raman tests anatase phase and Titania nanotubes have been distinguished. TEM confirmed TiNTs with pure structure. Vanadium catalyst with 5% of vanadia synthesized by impregnation method. Adding silicon in support increased thermal stability of catalyst. Raman and XRD method confirmed good distribution of active phase on supports. VSiTi catalyst have 28. 31% conversion and 51% selectivity in 550 oC. Improvement in yield of propylene production would be in result of higher surface area and good distribution of vanadia over modified Titania nanotubes.

The control of bacterial diseases of fish has always been one of the most important problems of aquaculteriets in recent years. One of these problems is bacterial resistance. Using antibiotics can cause problems for consumers. Therefore, the use of new antimicrobial agents with minimal complications is common. In the present study, using the acid-thermal method, the bentonite structure was modified and the chitosan and bentonite hybrids were modified in the stage of development. The structure of the compounds was studied using the Infrared Fourier Transform Spectrometry (FTIR), Surface Electron Scanning Microscopy (FE-SEM) and X-ray diffraction spectroscopy (EDX). Antimicrobial activity of two types of modified bentonite on gram negative bacterium Aeromonas hydrophila was studied in vitro using two methods of disk diffusion and microdilution. The results of the disc diffusion method showed that the antimicrobial compounds produced had antibacterial properties in experimental conditions against the Aeromonas hydrophilia bacteria. Antimicrobial activity (MIC and MBC) was determined using microdilution and clonal counting in Agar culture medium. The results showed that the modified compound with the acidic method had MBC of 28. 57 and 14. 28 mg / L for Aeromonas hydrophila bacteria in 10 minutes and 30 minutes. For chitosan and modified bentonite composite, MBC was 14. 28 mg / ml for Aeromonas hydrophila bacteria in 10 and 30 minutes. The results of this study showed that modified bentonite and composite compounds have strong antimicrobial effects and can remove pathogens in laboratory conditions and can be used as new compounds to control pathogens in breeding systems.