ADSORPTION OF MERCURIC ION FROM AQUEOUS SOLUTIONS USING MODIFIED FLY ASH

In this study, fly ash was treated with NaOH solution (FAN) before modifying with (3-mercaptopropyl) triethoxysilane - MPTMS (FAMPS). By using FTIR, FESEM, XRD, EDX, and BET techniques, the change in structure, composition and morphology of FAN and FAMPS was evaluated. The FTIR spectra of FAN and FAMPS showed that there is no chemical reaction between the MPTMS and FAN. After modification, the FAMPS has a rough surface with composition difference from the FAN. Mercuric ion adsorption behavior as well as adsorptionisotherm models (Langmuir and Freundlich) of the FAN and FAMPS were also investigated and discussed. Thanks to FAN modification, the mercuric ion removal percent of the FAMPS was higher than that of the FAN. Owing to the adsorption data, Freundlich isotherm modelwas fitted for the mercuric ion adsorption process

Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption.

This paper presents the results of adsorption ability of heavy metal ions (Hg2+ and Cd2+) by fly ash (FA) before and after treatment using NaOH and H2SO4 solutions.  Original- and treated FA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Specific surface area of FA before and after treatment was calculated by Brunauer – Emmett – Teller (BET) isotherm equation. The obtained results indicated that the morphology and specific surface area of FA changed clearly after treatment by acid or alkaline solutions. Adsorption capacity the Hg2+ and Cd2+ ion by FA was determined from data of UV-Vis spectra. After treatment, the adsorption capacity of ions by FA increased remarkably in comparison with non-treated FA. The FA treated by NaOH solution has the adsorption capacity higher than FA treated by H2SO4 solution. The maximum adsorption capacity of the FA treated by NaOH solution for Cd2+ and Hg2+ ions at room temperature is 28.97 and 14.60 mg/g, respectively. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. The results showed that equilibrium data were fitted well to the Langmuir isotherm. Keywords. Fly ash, treatment, adsorption capacity, heavy metal, Langmuir isotherm

Electrodeposition of HAp coatings on Ti6Al4V alloy and its electrochemical behavior in simulated body fluid solution

Hydroxyapatite (HAp) coatings were prepared on Ti6Al4V substrate by electrodeposition method from electrolyte solution containing Ca(NO3)2, NH4H2PO4 and NaNO3. The results show that the HAp coatings were single phase crystals of HAp. Scanning electron microscope (SEM) images present that HAp/Ti6Al4V have flake shapes which arrange to form like-coral agglomerates. In vitro test of the Ti6Al4V and HAp/Ti6Al4V in simulated body fluid (SBF) solution was investigated with different immersion times. pH of SBF solution decreased and the mass of materials increased. SEM images prove the formation of apatite on the surface of Ti6Al4V and HAp/Ti6Al4V. The corrosion current density during immersion time of substrate is always higher than the one of HAp/Ti6Al4V because the deposited HAp can protect well for the substrate

PREPARATION AND FTIR STUDIES OF PMMA/PVC POLYMER BLENDS, PVC-g-PMMA GRAFT COPOLYMERS AND EVALUATING GRAFT CONTENT

This study presents the qualitative and quantitative analyses of Fourier Transform Infrared (FTIR) spectra of poly(methyl methacrylate)/poly(vinyl chloride) blends (PMMA/PVC), as well as PVC-g-PMMA graft copolymers. Graft copolymerizations of methyl mathacrylate (MMA) onto PVC macromolecules were carried out mixture of cyclohexanone/N,N-dimethylformamide as solvents, dibenzoyl peroxide as initiator and nitrogen medium. FTIR spectra of PMMA/PVC blends showed that there were molecular interactions between C=O groups of PMMA and C-Cl groups of PVC. Assignments of infrared absorption bands for specific groups of PMMA/PVC blends have been contributed. Using regression method, linear calibration curve between PMMA mole content and peak areas of C=O groups in FTIR spectra of the blends has been found when C=O peak areas were multiplied by an appropriate factor. PMMA grafted content and total PMMA formed content in PVC-g-PMMA graft copolymers have been evaluated. The results showed that grafted PMMA content was increased since PVC was initiatly dechlorinated by NaOH solution. The grafted PMMA content and total formed PMMA content were 5.05 wt.% and 11.25 wt.% respectively when MMA monomers were grafted onto neat PVC and modified PVC molecules

EFFECT OF FISH SCALE COLLAGEN ON SOME CHARACTERISTICS AND DRUG RELEASE OF CARRAGEENAN/COLLAGEN/ALLOPURINOL FILM

ABSTRACT - QMFS2019Collagen from fish is attracting a lot of attention thanks to its high absorbance ability, biocompatibility as well as non-religious obstruction and cheap sources. It could be applied in many fields, for example: food, cosmetic, or biomedicine. Using of collagen also helps to reduce the environment pollution from fish scale waste in fish processing. In this study, collagen extracted from Vietnamese fresh-water tilapia fish scales was used in combination with carrageenan for the improvement of drug release control. The influence of fish scale collagen content on morphology, thermal behavior and drug release from carrageenan/collagen/allopurinol composite film was evaluated by methods such as field emission scanning electron microscopy (FESEM), differential scanning calorimetric (DSC) and ultraviolet-visible spectroscopy (UV-Vis). From the DSC data, FESEM analysis and drug release of carrageenan/collagen/allopurinol composite films, the most suitable collagen in composite film is 5 wt.%

ELECTRODEPOSITION OF HYDROXYAPATITE/FUNCTIONALIZED CARBON NANOTUBES (HAp/fCNTs) COATINGS ON THE SURFACE OF 316L STAINLESS STEEL

The coatings of hydroxyapatite/functionalized carbon nanotubes (HAp/fCNTs) were successfully synthesized on the surface of 316L stainless steel (316L SS) by electrodeposition. To improve the dispersion of CNTs into the electrolyte, CNTs were functionalized in the mixture of 67 % HNO3 and 98 % H2SO4 before electrodeposition coatings to form fCNTs. Different amounts of fCNTs were  incorporated into the apatite coatings by adding fCNTs into the  electrolyte solution. In this study, Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Thermal Gravimetric Analysis (TGA) and mechanical techniques were used to analyze characteristic of fCNTs and the HAp/fCNTs coatings. The FTIR spectra of CNTs before and after acid treated process show that CNTs are functionalized by chemically method with carboxylic acid groups (–COOH) on their surface. The SEM images confirm that the functionalized process by the acid mixture does not change the morphology of CNTs. The nanocomposite coatings contain single phase of HAp and CNTs with the coating thickness of 6.9 µm and the amount of fCNTs in the coatings is 7.25 %. With 0.5 g/L of fCNTs in the electrolyte solution, the solubility of the coating decreases in comparision with pure HAp coatings

Evaluation of factors related to entrepreneurial intentions among young pharmacists in the Mekong Delta region: a cross - sectional study in Vietnam

At present, a new wave of entrepreneurship has emerged and made a significant impact in Vietnam despite challenges. The study aims to assess the factors related to the entrepreneurial intentions of young pharmacists in 2023 in the Mekong Delta region. A cross-sectional descriptive method was conducted, involving interviews with 815 young pharmacists living in the Mekong Delta region, via a pre-designed research questionnaire. Results showed that 6 out of 43 variables were eliminated after Cronbach’s alpha was run. The Kaiser-Meyer-Olkin coefficient (0.5–0.923) indicated statistical significance and suitable conditions for Exploratory Factor Analysis. Confirmatory Factor Analysis and Structural Equation Modeling results were consistent with market data. With the impact of difficulties, attitude, perception of behavioral control, subjective norms, achievement needs on knowledge, and knowledge on entrepreneurial intentions (p < 0.05). In conclusion, the study successfully collected samples and gained a deeper understanding of the factors influencing the entrepreneurial intentions of young pharmacists

Tensile, electrical properties and morphology of polyethylene/modified fly ash composites using ultraflow

This paper presents relative melt viscosity, tensile, electrical properties and morphology of high density polyethylene (HDPE)/organo-modified fly ash (MFA) and HDPE/MFA/ultraflow (UTF) composites which were prepared by melt mixing method. Relative melt viscosity of HDPE was decreased with adding MFA and UTF into HDPE. Tensile properties (tensile strength, elongation at break and Young’s modulus) of HDPE/MFA/UTF composites were increased with rising UTF content to 5 wt.% and thereafter, they were dropped with the UTF content more than 5 wt.%. Electric properties (dielectric constant, dielectric loss and volume resistivity) of the HDPE/MFA and HDPE/MFA/UTF composites were investigated. The obtained parameters showed that the HDPE/MFA composites have electric insulation higher than HDPE/MFA/UTF composites. Morphology of the composite materials with and without using UTF was also studied by Field Emission Scanning Electron Microscopy (FESEM) images. The results indicated that the MFA was dispersed more regularly and less agglomerated in HDPE matrix with adding UTF into the HDPE/MFA composites

Synthesis and Characterization of Silver Nanoplates by a Seed-mediated Method

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag$^+$ ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods

INFLUENCE OF POLYETHYLENE OXIDE CONTENT ON SOME CHARACTERISTICS OF PLA/CS FILMS LOADING NIFEDIPINE

This work mentions the effect of polyethylene oxide (PEO) content on some characteristics and properties of polylactic acid (PLA)/chitosan (CS) films loading nifedipine (NIF). The water contact angle, droplet size values and Field Emission Scanning Electron Microscopy (FESEM) images  of the films are used to investigate their morphology and hydrophobicity. The obtained results show that the hydrophobic property of the PLA/CS/NIF films is improved by the presence of PEO. Besides, the PLA/CS/NIF films containing PEO have tighter structure and water absorbed ability less than those of the PLA/CS/NIF film