Journal of Applied Research in Chemistry
Year:2015 | Volume:9 | Issue:1|Papers Count:11

In this study effect of aminated polyacrylamid (PAa), glyoxylation of aminated polyacrylamid (G-PAM), and commercial polyamide-epichlorohydrin (PAE) resins on dry and wet strengths of dried paper as well as wet web strength of paper was investigated. Eexperiments showed that application of PAa improved paper strengths, and G-PAM produced by glyoxylation of PAa increased favorable effects of PAa on paper strengths. Wet strength of untreated paper and treated papers with 0.4% (based on dry weight of paper) of PAa, G-PAM and PAE were determined 0.09, 0.3, 0.65 and 0.53 N.m/g, respectively, which indicated higher improvement obtained by G-PAM relative to the PAa and commercial PAE. Also, dry strengths of paper improved more significantly by G-PAM in comparison to the PAa and PAE, while application of 0.4% G PAM increased tensile and burst strengths and tensile energy absorption (TEA) by 21.7%, 29.2% and 69%, respectively. Surprisingly, G-PAM improved tensile strength of wet web of paper by 13.4% which could be attributed to the higher reactivity of residual glyoxal in the ambient temperature.

Blends of Poly Vinyl Chloride/Epoxidized Natural Rubber (PVC/ENR50) with 70/30 and 50/50 wt%, based on nanocomposites containing the constant amount of organoclay (3 wt% Cloisite30B) were prepared by melt mixing process. XRD, SEM and RMS were used to study the nonocomposite microstructure, dispersion of nanolayers and rheological properties, respectively. Mechanical properties of samples were investigated by tensile test. XRD images indicated intercalation structure of nanolayers in the polymer blends. Also, the melt rheological behavior demonstrated that the addition of organoclay to the PVC/ENR50 blend increases the complex viscosity and storage modulus becomes independent of frequency in low frequency which indicates uniform dispersion and enhanced interaction between nanolayers and polymer matrix. The obtained results revealed that the addition of Closite30B to PVC/ENR50 compound with 70/30 wt% composition had enhanced properties compared to the sample containing 50/50 wt% composition. This can be attributed to uniform dispersion of closite30B in the more polar matrix blend that contains more PVC. SEM images from fractured surface of samples and also results of the mechanical properties are consistent with the results mentioned above.

Noble gases are considered "inert" although theoretical and experimental chemists have reported their limited reactivity with other elements, recently. In this paper, we consider the structures of HNgY…N2 and HNgY…HX by geometrical optimization, nuclear magnetic resonance (NMR), and atoms in molecules (AIM) tools. MP2 calculations with aug-cc pVDZ, 6-311++g (2d, 2p) and DGDZVP basis sets were used to analyze the different systems. For the all compounds, total energy and relative stability are calculated. After the complexation, noble gas compounds are stable because of the presence of the heavy nuclei. The nucleus shielding is due to interaction HNgY…N2 (all forms) and HNgY…HX (structure 1, 2). The AIM results show remarkably good agreement with the NMR study results obtained on the HNgY…N2 compounds.

Biphasic calcium phosphates (BCPs) of hydroxyapatite/Octacalcium phosphate (HA/OCP) with mixed morphology of whisker/spherulite were synthesized and characterized by the precipitationhydrolysis method in an acidic solution containing calcium and phosphate ions and carbonyl diamide. The synthesized solutions were refluxed at 90 °C for 3 or 4 days. The crystalline structure of products was determined by X−ray diffraction (XRD). Fourier transformed infra-red spectroscopy (FTIR) was used to characterize the absorption spectrum. The morphology of products was evaluated by scanning electron microscopy (SEM). The results showed the presence of carbonyl diamide (CA) in synthesized solutions with a Ca/P molar ratio of 1.67 led spherulites to be formed and then whiskers such that an increase of CA concentration was associated with an increase in whisker length and a decrease in spherulite diameter. The concentration of CA was more effective than calcium concentration and Ca/P molar ratio on the size of whiskers. The increase of reaction time may give rise to change the morphology of whiskers to lath-like one (increasing the whisker width) and spherulites from flowerlike forms to microspheres. The appropriate chitosan-based composite scaffolds containing various amounts of calcium phosphate phase with a homogenous microstructure of 65−80 porosity are percent and pore size of 50-400 μm could be produced for hard tissue engineering applications. The porosity of scaffolds was decreased with increasing the calcium phosphate phase.

In this research, we propose the best method for the synthesis of Magnesium oxide nanostructures as precursor for the synthesis of Magnesium Oleate. Magnesium oxide nanoparticles have been synthesized with different methods such as co- precipitation, microwave, and ball milling. The samples were characterized by XRD, SEM and TEM. After analysis, the best samples were selected based on their morphology and their average particle size. Magnesium Oleate was synthesized by the as-prepared Magnesium oxide nanostructures and characterized with Total Base Number (TBN). The corrosion inhibition property of the sample which had the highest TBN amount was determined according to the NACE 1 D 182 standard test method. The corrosion inhibitor that contains Magnesium Oleate will be economical because of its simple method of synthesis and required equipments that are used, lower dosage in comparison to the similar commercial product, and using commercial grade of starting materials.

In this study, allicin was encapsulated into the biodegradable polymers byionotropic pre-gelation method. The particle size and encapsulation efficiency of the encapsulated allicin were assessed with consideration of three variables including concentration of chitosan, concentration of sodium alginate, and pH of solution. The results showed that with increasing the concentration of chitosan and sodium alginate, the particle size increases and the encapsulation efficiency decreases and also decreasing the pH caused to the increasing of the particle size and decreasing of the encapsulation efficiency. The appropriate range for concentration of chitosan and sodium alginate was between 0.75 to1. 5 and 2.6 to 3 mg/ml, respectively. The pH between . and 5.7 was acceptable pH at which we had smaller particles and higher encapsulation efficiency. Nanoparticles were characterized using Field emission scanning electron microscopy (FE-SEM).

In the multi stage flash distillation type of brackish water desalination, the main stream supply feed water is rejected. This water actually is the cooling water which adsorbs the latent heat of vapors of the recirculating boiling brine in the heat rejection evaporator and leads to produce distillate water. In the industries like petroleum refineries, which are located beside the rivers, raw water after pretreatment and clarification with coagulants and other chemicals, now named clarified water, goes to water desalination plant as feed water. The return of more than 50 percent of the treated water to the river with around 14oC temperature increase which is not acceptable and considered as waste. Nevertheless, by using cooling tower system, it can be recycled in this process. This paper represents optimization of water desalination process in a petroleum refinery as a case study, where for the first time; the result of this study has been performed. In this research, it is clearly shown that how by using of proper data gathering, modeling and simulation of process with appropriate use of equations and employment of the basic concepts of thermodynamic a significant saving can be achieved. It is found that for each of three exist thermal desalination plants up to 52 percent of feed water, i.e.; 667 m3/h and same amount of reject water can be conserved. Though, with this modification, the unit steam consumption has been increased up to 13 ton/h, about 50 percent of design.

Preparetion of molecularly imprinted polymers is a new, simple, and inexpensive method for preparing materials that can be used in several clinical applications. In this study, glucose imprinted and nonimprinted nanoparticles were synthesized by free radical polymerization under heating method in which acrylamide (AA) acts as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linke. The obtained molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs) nanoparticles characterized by using field emission scanning electron microscopy (FE-SEM) and fourier transform infrared spectroscopy (FT-IR). The adsorption test showed that polyacrylamide nanoparticles with average size of 33.5 nm exhibited a good selectivity to glucose compared to fructose, and ascorbic acid.