Displaying publications 61 - 80 of 181 in total

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  1. Fulltext Effect of Ratio in Ammonium Nitrate on the Structural, Microstructural, Magnetic, and AC Conductivity Properties of BaFe12O19
    Azis RS, Che Muda NN, Hassan J, Shaari AH, Ibrahim IR, Mustaffa MS, et al.
    Materials (Basel), 2018 Nov 06;11(11).
    PMID: 30404131 DOI: 10.3390/ma11112190
    This paper investigates the effect of the ratio of ammonium nitrate (AN) on the structural, microstructural, magnetic, and alternating current (AC) conductivity properties of barium hexaferrite (BaFe12O19). The BaFe12O19 were prepared by using the salt melt method. The samples were synthesized using different powder-to-salt weight ratio variations (1:3, 1:4, 1:5, 1:6 and 1:7) of BaCO₃ + Fe₂O₃ and ammonium nitrate salt. The NH₄NO₃ was melted on a hot plate at 170 °C. A mixture of BaCO₃ and Fe₂O₃ were added into the NH₄NO₃ melt solution and stirred for several hours using a magnetic stirrer under a controlled temperature of 170 °C. The heating temperature was then increased up to 260 °C for 24 hr to produce an ash powder. The x-ray diffraction (XRD) results show the intense peak of BaFe12O19 for all the samples and the presence of a small amount of the impurity Fe₂O₃ in the samples, at a ratio of 1:5 and 1:6. From the Fourier transform infra-red (FTIR) spectra, the band appears at 542.71 cm - 1 and 432.48 cm - 1 , which corresponding to metal⁻oxygen bending and the vibration of the octahedral sites of BaFe12O19. The field emission scanning electron microscope (FESEM) images show that the grains of the samples appear to stick each other and agglomerate at different masses throughout the image with the grain size 5.26, 5.88, 6.14, 6.22, and 6.18 µm for the ratios 1:3, 1:4, 1:5, 1:6, and 1:7 respectively. From the vibrating sample magnetometer (VSM) analysis, the magnetic properties of the sample ratio at 1:3 show the highest value of coercivity Hc of 1317 Oe, a saturation magnetization Ms of 91 emu/g, and a remnant Mr of 44 emu/g, respectively. As the temperature rises, the AC conductivity is increases with an increase in frequency.
    Matched MeSH terms: Fourier Analysis
  2. Fulltext Synthesis and adsorption studies for newly prepared Ni2+-imprinted polymer co-functionalized with picolinic acid
    Mehamod, F.S., Kadir, M.A., Jusoh, N., Yusof, N.F., Suah, F.B.
    ASM Science Journal, 2018;11(101):114-123.
    MyJurnal
    The development of new adsorbent has rapidly increased in order to overcome the problem
    of waste water treatment from heavy metal pollution. The ability of nickel (II)-ion imprinted
    polymer (Ni-IIP) as an alternative adsorbent for the removal of nickel ion from aqueous has
    been investigated. The Ni-IIP was prepared via bulk polymerization by using functional
    monomers; methylacrylic acid (MAA) with picolinic acid as a co-monomer. Nickel ion was
    used as template, AIBN as initiator and EGDMA as cross-linking agent. Non-imprinted control
    polymer (NIP) was prepared in the same manner as Ni-IIP but in the absence of nickel
    ion. The resultant of Ni-IIP and NIP were characterized by using Fourier Transform Infrared
    (FTIR) spectroscopy and Scanning Electron Microscope (SEM). Result showed that, the adsorption
    of nickel ion onto Ni-IIP increased as the adsorbent dosage increased and contact
    time is prolonged. The adsorption isotherm model for Ni-IIP and NIP were fitted well with
    Freundlich and Langmuir, respectively. Kinetic study for both Ni-IIP and NIP were followed
    the pseudo-second order, indicates that the rate-limiting step is the surface adsorption that
    involves chemisorption. Selectivity studies showed that the distribution coefficient of Ni2+
    was higher compared to Zn2+, Mg2+ and Pb2+. The present work has successfully synthesized
    Ni-IIP particles with good potential in recognition of Ni2+ ions in an aqueous medium.
    Matched MeSH terms: Fourier Analysis
  3. Fulltext Preparation and characterization of yttrium barium copper oxide (YBCO) superconductor with addition of cobalt oxide (Co3O4)
    Jannah, A.N., Erwana, N.Y., Jamion, N.A.
    Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2018;6(1):31-38.
    MyJurnal
    This study was carried out to investigate the electrical properties of YBCO sample as superconductor
    and the effect of addition of Co3O4 on the superconducting properties of YBCO superconductor. The
    YBCO sample was prepared by solid state reaction route. The samples were prepared by each with
    weight percentage of cobalt oxide of x= 0.00, x= 0.01, x= 0.02 and x= 0.03. Electrical Conduction by
    Multimeter, Fourier Transform Infrared (FTIR), Critical temperature (Tc) measurement, X-ray
    Diffraction (XRD), and Scanning Electron Microscopy (SEM) were conducted for analysis.
    Multimeter showed all samples were in electric conduction, FTIR showed that carbonyl compound in
    the sample was removed after calcinations. Tc measurement showed that the critical temperature of
    sample of x= 0.02 was increased compared to sample of x= 0.00. XRD showed all samples have
    orthorhombic structure and SEM showed that the grain size was increased as increased the cobalt
    addition in YBCO superconductor. Besides, the EDX also showed the composition of elements
    YBCO were tally with chemicals used for pure YBCO and addition cobalt oxide into YBCO
    superconductor.
    Matched MeSH terms: Fourier Analysis
  4. Tribological behaviour of OA-capped WO3 nanoparticles as an additive to base oils
    Siti Fazlili Abdullah, Shahidan Radiman, Muhammad Azmi Abdul Hamid, Noor Baa’yah Ibrahim
    Sains Malaysiana, 2008;37:233-237.
    Oleic acid (OA) capped wolfram (VI) oxide, WO3 nanoparticles were chemically synthesized and characterized by means of Fourier Transform-Infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The tribological properties of the capped WO3 nanoparticles as an additive in base oils were investigated using a four-ball machine. Results show that OA-capped WO3 nanoparticles are able to prevent water adsorption and capable of being dispersed stable in organic solvents which is base oils. The as-prepared capped WO3 nanoparticles have an average size of 15 nm. In addition, OA-capped WO3 nanoparticles as an additive in base oils perform good anti-wear (AW) and anti-friction (AF) properties owing to the formation of a boundary film.
    Matched MeSH terms: Fourier Analysis
  5. Investigation of the gelation mechanism between amino acid surfactant based microemulsion and Kappa-Carrageenan gel network
    Nasima Akter, Shahidan Radiman, Faizal Mohamed, Nazaruddin Ramly, Putra EGR, Rini AS
    Sains Malaysiana, 2014;43:203-209.
    Kappa-carrageenan is one form of necessary hydrocolloid. Hydrocolloids are macromolecular materials, which swell upon absorption of water; in some cases, forming a stiff gel in the presence of additives. This property is very important to suspend nanocarriers into gel network, which provide them long time stability at a varying temperature range. In this work, we prepared microemulsion and trapped these particles inside the kappa-carrageenan gel network. The microemulsion was composed of sodium N-lauroylsarcosinate hydrate (SNLS), oleic acid and deionized water. The purpose of this study was to immobilize them into the gel network, giving longer shelf life at a range of temperatures for oral drug delivery. Morphological properties were investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and Fourier transform infrared (FTIR) spectra. The TEM results showed that microemulsions are trapped in the gel network, and the diameter of the microemulsions are below 100 nm, which is comparable with the DLS results. The important functional groups of kappa-carrageenan and microemulsion were shown from the FTIR result of the complex microemulsion gel. These results confirmed the interaction between SNLS based microemulsion and kappa- carrageenan gel.
    Matched MeSH terms: Fourier Analysis
  6. Fulltext Extraction and Characterization of Cellulose Nanocrystals from Tea Leaf Waste Fibers
    Abdul Rahman NH, Chieng BW, Ibrahim NA, Abdul Rahman N
    Polymers (Basel), 2017 Nov 07;9(11).
    PMID: 30965890 DOI: 10.3390/polym9110588
    The aim was to explore the utilization of tea leaf waste fibers (TLWF) as a source for the production of cellulose nanocrystals (CNC). TLWF was first treated with alkaline, followed by bleaching before being hydrolyzed with concentrated sulfuric acid. The materials attained after each step of chemical treatments were characterized and their chemical compositions were studied. The structure analysis was examined by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). From FTIR analysis, two peaks at 1716 and 1207 cm-1-which represent C=O stretching and C⁻O stretching, respectively-disappeared in the spectra after the alkaline and bleaching treatments indicated that hemicellulose and lignin were almost entirely discarded from the fiber. The surface morphology of TLWF before and after chemical treatments was investigated by scanning electron microscopy (SEM) while the dimension of CNC was determined by transmission electron microscopy (TEM). The extraction of CNC increased the surface roughness and the crystallinity index of fiber from 41.5% to 83.1%. Morphological characterization from TEM revealed the appearance of needle-like shaped CNCs with average diameter of 7.97 nm. The promising results from all the analyses justify TLWF as a principal source of natural materials which can produce CNC.
    Matched MeSH terms: Fourier Analysis
  7. Fulltext Isolation and Characterization of Cellulose Nanocrystals from Oil Palm Mesocarp Fiber
    Chieng BW, Lee SH, Ibrahim NA, Then YY, Loo YY
    Polymers (Basel), 2017 Aug 11;9(8).
    PMID: 30971032 DOI: 10.3390/polym9080355
    The aim was to explore the utilization of oil palm mesocarp fiber (OPMF) as a source for the production of cellulose nanocrystals (CNC). OPMF was first treated with alkali and then bleached before the production of CNC by acid hydrolysis (H₂SO₄). The produced materials were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), a scanning electron microscope (SEM) and a transmission electron microscope (TEM). It was proven that acid hydrolysis can increase the crystallinity of bleached OPMF and reduce the dimension of cellulose to nano scale. Changes in the peaks of the FTIR spectrum at 2852 (C-H stretching), 1732 (C=O stretching) and 1234 cm-1 (C-O stretching) indicated that the alkali treatment completely removed hemicelluloses and lignin from the fiber surface. This can be seen from the thermogram obtained from the TGA characterization. Morphological characterization clearly showed the formation of rod-shaped CNCs. The promising results prove that OPMF is a valuable source for the production of CNC.
    Matched MeSH terms: Fourier Analysis
  8. Fulltext Thixotropic Supramolecular Pectin-Poly(Ethylene Glycol) Methacrylate (PEGMA) Hydrogels
    Chan SY, Choo WS, Young DJ, Loh XJ
    Polymers (Basel), 2016 Nov 18;8(11).
    PMID: 30974681 DOI: 10.3390/polym8110404
    Pectin is an anionic, water-soluble polymer predominantly consisting of covalently 1,4-linked α-d-galacturonic acid units. This naturally occurring, renewable and biodegradable polymer is underutilized in polymer science due to its insolubility in organic solvents, which renders conventional polymerization methods impractical. To circumvent this problem, cerium-initiated radical polymerization was utilized to graft methoxy-poly(ethylene glycol) methacrylate (mPEGMA) onto pectin in water. The copolymers were characterized by ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), and used in the formation of supramolecular hydrogels through the addition of α-cyclodextrin (α-CD) to induce crosslinking. These hydrogels possessed thixotropic properties; shear-thinning to liquid upon agitation but settling into gels at rest. In contrast to most of the other hydrogels produced through the use of poly(ethylene glycol) (PEG)-grafted polymers, the pectin-PEGMA/α-CD hydrogels were unaffected by temperature changes.
    Matched MeSH terms: Fourier Analysis
  9. Fulltext Poly(Acrylic acid)⁻Based Hybrid Inorganic⁻Organic Electrolytes Membrane for Electrical Double Layer Capacitors Application
    Liew CW, Ng HM, Numan A, Ramesh S
    Polymers (Basel), 2016 May 18;8(5).
    PMID: 30979292 DOI: 10.3390/polym8050179
    Nanocomposite polymer electrolyte membranes (NCPEMs) based on poly(acrylic acid)(PAA) and titania (TiO₂) are prepared by a solution casting technique. The ionic conductivity of NCPEMs increases with the weight ratio of TiO₂.The highest ionic conductivity of (8.36 ± 0.01) × 10-4 S·cm-1 is obtained with addition of 6 wt % of TiO₂ at ambient temperature. The complexation between PAA, LiTFSI and TiO₂ is discussed in Attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR) studies. Electrical double layer capacitors (EDLCs) are fabricated using the filler-free polymer electrolyte or the most conducting NCPEM and carbon-based electrodes. The electrochemical performances of fabricated EDLCs are studied through cyclic voltammetry (CV) and galvanostatic charge-discharge studies. EDLC comprising NCPEM shows the specific capacitance of 28.56 F·g-1 (or equivalent to 29.54 mF·cm-2) with excellent electrochemical stability.
    Matched MeSH terms: Fourier Analysis
  10. Fulltext Acacia Holosericea: An Invasive Species for Bio-char, Bio-oil, and Biogas Production
    Reza MS, Ahmed A, Caesarendra W, Abu Bakar MS, Shams S, Saidur R, et al.
    Bioengineering (Basel), 2019 Apr 16;6(2).
    PMID: 30995765 DOI: 10.3390/bioengineering6020033
    To evaluate the possibilities for biofuel and bioenergy production Acacia Holosericea, which is an invasive plant available in Brunei Darussalam, was investigated. Proximate analysis of Acacia Holosericea shows that the moisture content, volatile matters, fixed carbon, and ash contents were 9.56%, 65.12%, 21.21%, and 3.91%, respectively. Ultimate analysis shows carbon, hydrogen, and nitrogen as 44.03%, 5.67%, and 0.25%, respectively. The thermogravimetric analysis (TGA) results have shown that maximum weight loss occurred for this biomass at 357 °C for pyrolysis and 287 °C for combustion conditions. Low moisture content (<10%), high hydrogen content, and higher heating value (about 18.13 MJ/kg) makes this species a potential biomass. The production of bio-char, bio-oil, and biogas from Acacia Holosericea was found 34.45%, 32.56%, 33.09% for 500 °C with a heating rate 5 °C/min and 25.81%, 37.61%, 36.58% with a heating rate 10 °C/min, respectively, in this research. From Fourier transform infrared (FTIR) spectroscopy it was shown that a strong C-H, C-O, and C=C bond exists in the bio-char of the sample.
    Matched MeSH terms: Fourier Analysis
  11. pH sensitive hydrogel based on poly(acrylic acid) and cellulose nanocrystals
    Lim SL, Ishak Ahmad, Azwan Mat Lazim
    Sains Malaysiana, 2015;44:779-785.
    The purpose of this study was to produce a novel pH sensitive hydrogel with superior thermal stability, composed of
    poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali
    and bleaching treatments followed by acid hydrolysis. PAA was then subjected to chemical cross-linking using the crosslinking
    agent (N,N-methylenebisacrylamide) in CNC suspension. The mixture was casted onto petri dish to obtain disc
    shape hydrogel. PAA/cellulose hydrogel with the same composition ratio were also prepared as control. The effect of
    reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH
    was studied. The obtained hydrogel was further subjected to different tests such as thermogravimetric analysis (TGA) to
    study the thermal behavior, Fourier transform infrared for functional group identification and swelling test for swelling
    behavior at different pH. The cross-linking of PAA was verified with FTIR with the absence of C=C double bond. In TGA
    test, PAA/CNC hydrogel showed significantly higher thermal stability compared with pure PAA hydrogel. The hydrogel
    obtained showed excellent pH sensitivity and experienced maximum swelling at pH7. The PAA/CNC hydrogel can be
    developed further as drug carrier
    Matched MeSH terms: Fourier Analysis
  12. Effects of silane surface treatment of cellulose nanocrystals on the tensile properties of cellulose-polyvinyl chloride nanocomposite
    Rasha M. Sheltami, Hanieh Kargarzadeh, Ibrahim Abdullah
    Sains Malaysiana, 2015;44:801-810.
    Cellulose nanocrystals (CNC) from mengkuang leaves (Pandanus tectorius) were investigated as potential reinforcement
    in poly(vinyl chloride) (PVC) matrix. The surface of CNC was modified with silane coupling agent to improve fillermatrix
    adhesion. Solution casting method was used to prepare PVC nanocomposites with various amounts of modified
    (SCNC) and unmodified (CNC) nanocrystals. Both SCNC and CNC were examined by Fourier transform infrared (FTIR)
    spectroscopy and X-ray diffraction (XRD) which showed that surface chemical modification has occurred. An increase
    in tensile strength was observed with the addition of SCNC compared to the CNC. However, the elongation at break of the
    nanocomposites was found to decrease with the increase of both fillers loading. An increasing trend was observed in the
    tensile modulus with the addition of CNC to the PVC matrix, but decreasing with the addition of SCNC. The morphology
    of a fractured surface of nanocomposites showed silane modification reduced the number of voids in the structure of
    PVC. The observation indicated the adhesion between the fiber and the matrix had improved upon surface modification
    of the nanocrystals with silane.
    Matched MeSH terms: Fourier Analysis
  13. Isolation and fractionation of cellulose nanocrystals from kenaf core
    Hanisah Syed Sulaiman, Chin HC, Chan CH, Sarani Zakaria, Sharifah Nabihah Syed Jaafar
    Sains Malaysiana, 2015;44:1635-1642.
    In this study, cellulose nanocrystals (CNC) were produced using acid hydrolysis method. Kenaf core was pretreated with 4
    wt. % sodium hydroxide (NaOH), followed by bleaching using 1.7 wt. % sodium chlorite (NaClO2
    ) in acetate buffer. The
    bleached fiber was acid hydrolyzed for 45 and 55 min using 64 wt. % sulfuric acid (H2
    SO4
    ). The size distribution of the
    CNC segregated via differential centrifugation with different speed was also investigated. The CNC suspension obtained
    was centrifuged at 3000, 6000, 9000 and 12000 rpm. The resultant CNC suspension collected was characterized using
    Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR
    results showed the progressive removal of non-cellulosic constituents for each subsequent treatment. It also showed that
    the CNC produced after hydrolysing for 55 min has the highest degree of crystallinity (81.15%). CNC produced from acid
    hydrolysis process of 45 min have lengths between 50 and 270 nm while CNC produced from acid hydrolysis process of
    55 min have length around 40 to 370 nm.
    Matched MeSH terms: Fourier Analysis
  14. Linear low density polyethylene/poly (vinyl alcohol)/kenaf composites: effect of natural weathering on functional group, weight loss characteristics, tensile, morphological and thermal properties
    Pang AL, Azhar Abu Bakar, Hanafi Ismail
    Sains Malaysiana, 2018;47:571-580.
    The development of natural fiber polymer composites is increasing worldwide and in some applications, these composites
    are used at outdoor rendering them exposed to ultra-violet (UV) radiation. The paper investigates the degradation behavior
    of linear low density polyethylene/poly (vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites after exposure to different
    natural weathering durations. The composites with KNF loadings of 10, 20 and 40 parts per hundred resin (phr) were
    exposed to natural weathering for 3 months and 6 months, respectively. The weathered composites were characterized by
    Fourier transform infrared (FTIR) spectroscopy, universal testing machine, field emission scanning electron microscopy
    (FESEM) and differential scanning calorimetry (DSC). The FTIR analysis showed an obvious carbonyl peak in composites
    after weathering as an evidence of oxidation. The weight loss percentage of composites increased with respect to exposure
    duration due to higher absorption of UV irradiation. The tensile properties of weathered composites were lower than
    that of control composites and these properties also decreased with increasing exposure duration. FESEM micrographs
    illustrated that composites with longer exposure duration suffered more surface damaged. The crystallinity percentage
    was found to increase with increasing exposure duration.
    Matched MeSH terms: Fourier Analysis
  15. Preparation and characterization of impregnated magnetic particles on Oil Palm Frond Activated Carbon for metal ions removal
    Muzakkir Mohammad Zainol, Nor Aishah Saidina Amin, Mohd Asmadi
    Sains Malaysiana, 2017;46:773-782.
    The magnetic adsorbents i.e. oil palm frond-magnetic particles (OPF-MP) and oil palm frond activated carbon-magnetic particles (OPFAC-MP) have been prepared by impregnation of iron oxide via co-precipitation method. The magnetic adsorbents and their parent materials were characterized using Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), Brunauer Emmett Teller (BET), Barrett, Joyner & Halenda (BJH) and t-plot method, x-ray diffraction (XRD) and also using vibrating sample magnetometry (VSM) to study their properties and surface chemistry. The activated carbon magnetic adsorbent confers high surface area of 700 m2/g with amorphous structure and magnetic properties of 2.76 emu/g. The OPF-MP and OPFAC-MP were then applied in adsorption study for ions removal of Pb(II), Zn(II) and Cu(II). OPFAC-MP has shown high removal efficiency of 100 % with adsorption capacity up to 15 mg/g of Pb(II), Zn(II) and Cu(II) ions compared to OPF-MP. In addition, the magnetic adsorbents were also compared with their parent materials to observe the effect of magnetic particles. Accordingly, the impregnation of magnetic particles enhances the metal ions adsorption comparing to their parent materials.
    Matched MeSH terms: Fourier Analysis
  16. Epoxidation and hydroxylation of liquid natural rubber
    Nur Hanis Adila Azhar, Nur Hanis Adila Azhar Hamizah Md Rasid, Siti Fairus M. Yusoff
    Sains Malaysiana, 2017;46:485-491.
    Liquid natural rubber (LNR) was functionalized into liquid epoxidized natural rubber (LENR) and hydroxylated LNR (LNROH)
    via oxidation using a Na2
    WO4
    /CH3
    COOH/H2
    O2
    catalytic system. Microstructures of LNR and functionalized LNRs
    were characterized using Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies. The
    effect of CH3
    COOH, H2
    O2
    , Na2
    WO4
    , reaction time and temperature. reaction time and temperature on epoxy content were
    investigated. LNR-OH was obtained when oxidation reaction was conducted at a longer reaction time, higher temperature
    or excess amount of catalyst. Thermogravimetric analysis (TGA) reported the thermal behavior of functionalized LNRs.
    Molecular weight and polydispersity index (PDI) were determined using gel permeation chromatography (GPC).
    Matched MeSH terms: Fourier Analysis
  17. A novel ruthenium-tungsten bimetallic complex dye-sensitizer for photoelectrochemical cells application
    Khuzaimah Arifin, Wan Ramli Wan Daud, Mohammad B. Kassim
    Sains Malaysiana, 2014;43:95-101.
    A novel bimetallic double thiocyanate-bridged ruthenium and tungsten metal complex containing bipyridyl and dithiolene co-ligands was synthesized and the behavior of the complex as a dye-sensitizer for a photoelectrochemical (PEG) cell for a direct water splitting reaction was investigated. The ligands and metal complexes were characterized on the basis of elemental analysis as well as uv-Vis, Fourier transform infrared ( Pim) and nuclear magnetic resonance (11I and 13C NMR) spectroscopy. Cyclic voltammetry of the bimetallic complex showed multiple redox couples, in which half potentials E 112 at 0 .625 , 0.05 and 0.61 V were assigned as the formal redox processes of Ru(III)IRu(II) reduction, W(IV)IW(V) and W(V)IW(VI) oxidations, respectively. Photocurrent measurements were performed in homogeneous system and TiO2 was used as the photoanode for photocurrent measurements. Current density generated by the bimetallic complex was higher than that of N3 commercial dye which suggested that the bimetallic complex donated more electrons to the semiconductor.
    Matched MeSH terms: Fourier Analysis
  18. Effect of Synthesis Temperature on the Morphologies, Optical and Electrical Properties of MgO Nanostructures
    Sagadevan S, Venilla S, Marlinda AR, Johan MR, Wahab YA, Zakaria R, et al.
    J Nanosci Nanotechnol, 2020 Apr 01;20(4):2488-2494.
    PMID: 31492266 DOI: 10.1166/jnn.2020.17185
    Herein, we report the effect of synthesis temperature on the morphologies, optical and electronic properties of magnesium oxide (MgO) nanostructures. The MgO nanostructures were synthesized at different temperatures, i.e., 100 °C, 300 °C, and 600 °C by simple chemical reaction process and their morphology, particle size, optical, and electrical properties were examined by different techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and UV-Vis. spectroscopy. The morphological investigations revealed that various morphologies of MgO nanostructures, i.e., nanoparticles, nanosheet networks, and nanoneedles were synthesized at 100 °C, 300 °C, and 600 °C. The XRD results confirmed that with increasing the synthesis temperature, the crystallinity of the synthesized nanostructures increases. Further, the dielectric properties and AC conductivity at various frequencies for MgO nanostructures were studied which revealed that the dielectric losses decrease with increase in frequency and temperature. In addition, the observed band gap decreases from 4.89 eV to 4.438 eV (100 °C to 600 °C) representing its increase in the conductivity.
    Matched MeSH terms: Fourier Analysis
  19. Fulltext Preparation and In Vitro Evaluation of Neutron-Activated, Theranostic Samarium-153-Labeled Microspheres for Transarterial Radioembolization of Hepatocellular Carcinoma and Liver Metastasis
    Wong YH, Tan HY, Kasbollah A, Abdullah BJJ, Yeong CH
    Pharmaceutics, 2019 Nov 12;11(11).
    PMID: 31718079 DOI: 10.3390/pharmaceutics11110596
    INTRODUCTION: Transarterial radioembolization (TARE) has been proven as an effective treatment for unresectable liver tumor. In this study, neutron activated, 153Sm-labeled microspheres were developed as an alternative to 90Y-labeled microspheres for hepatic radioembolization. 153Sm has a theranostic advantage as it emits both therapeutic beta and diagnostic gamma radiations simultaneously, in comparison to the pure beta emitter, 90Y.

    METHODS: Negatively charged acrylic microspheres were labeled with 152Sm ions through electrostatic interactions. In another formulation, the Sm-labeled microsphere was treated with sodium carbonate solution to form the insoluble 152Sm carbonate (152SmC) salt within the porous structures of the microspheres. Both formulations were neutron-activated in a research reactor. Physicochemical characterization, gamma spectrometry, and radiolabel stability tests were carried out to study the performance and stability of the microspheres.

    RESULTS: The Sm- and SmC-labeled microspheres remained spherical and smooth, with a mean size of 35 µm before and after neutron activation. Fourier transform infrared (FTIR) spectroscopy indicated that the functional groups of the microspheres remained unaffected after neutron activation. The 153Sm- and 153SmC-labeled microspheres achieved activity of 2.53 ± 0.08 and 2.40 ± 0.13 GBq·g-1, respectively, immediate after 6 h neutron activation in the neutron flux of 2.0 × 1012 n·cm-2·s-1. Energy-dispersive X-ray (EDX) and gamma spectrometry showed that no elemental and radioactive impurities were present in the microspheres after neutron activation. The retention efficiency of 153Sm in the 153SmC-labeled microspheres was excellent (~99% in distilled water and saline; ~97% in human blood plasma), which was higher than the 153Sm-labeled microspheres (~95% and ~85%, respectively).

    CONCLUSION: 153SmC-labeled microspheres have demonstrated excellent properties for potential application as theranostic agents for hepatic radioembolization.

    Matched MeSH terms: Fourier Analysis
  20. Fulltext Application of Biochar Derived From Pyrolysis of Waste Fiberboard on Tetracycline Adsorption in Aqueous Solution
    Xu D, Gao Y, Lin Z, Gao W, Zhang H, Karnowo K, et al.
    Front Chem, 2019;7:943.
    PMID: 32117859 DOI: 10.3389/fchem.2019.00943
    In this study, biochars derived from waste fiberboard biomass were applied in tetracycline (TC) removal in aqueous solution. Biochar samples were prepared by slow pyrolysis at 300, 500, and 800°C, and were characterized by ultimate analysis, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), etc. The effects of ionic strength (0-1.0 mol/L of NaCl), initial TC concentration (2.5-60 ppm), biochar dosage (1.5-2.5 g/L), and initial pH (2-10) were systemically determined. The results present that biochar prepared at 800°C (BC800) generally possesses the highest aromatization degree and surface area with abundant pyridinic N (N-6) and accordingly shows a better removal efficiency (68.6%) than the other two biochar samples. Adsorption isotherm data were better fitted by the Freundlich model (R2 is 0.94) than the Langmuir model (R2 is 0.85). Thermodynamic study showed that the adsorption process is endothermic and mainly physical in nature with the values of ΔH0 being 48.0 kJ/mol, ΔS0 being 157.1 J/mol/K, and ΔG0 varying from 1.02 to -2.14 kJ/mol. The graphite-like structure in biochar enables the π-π interactions with a ring structure in the TC molecule, which, together with the N-6 acting as electron donor, is the main driving force of the adsorption process.
    Matched MeSH terms: Fourier Analysis
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