Displaying publications 321 - 340 of 1023 in total

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  1. Ibrahim Lakin I, Abbas Z, Azis RS, Ibrahim NA, Abd Rahman MA
    Materials (Basel), 2020 Oct 14;13(20).
    PMID: 33066690 DOI: 10.3390/ma13204581
    Oil palm empty fruit bunch (OPEFB) fiber/polylactic acid (PLA)-based composites filled with 6-22 wt.% multi-walled carbon nanotubes (MWCNTs) were prepared using a melt blend method. The composites were analyzed using X-ray diffraction (XRD), Fourier transforms infrared (FTIR), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) of the MWCNTs. The composites were characterized for complex permittivity using the coaxial probe at 8-12 GHz range and the transmission/reflection coefficients were measured through micro strip line. The dielectric permittivity measurements carried out at X-band frequency revealed that 22 wt.% MWCNTs nanocomposite display higher dielectric constant (ε') and dielectric loss (ε″) values of 4.23 and 0.65, respectively. A maximum absorption loss of 15.2 dB was obtained for the 22 wt.% nanocomposites at 11.75 GHz. This result suggests that PLA/OPEFB/MWCNTs composites are a promising cheap and lightweight material for the effective microwave absorption in the X-band frequency range.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  2. Nguyen DH, Vo TNN, Nguyen NT, Ching YC, Hoang Thi TT
    PLoS One, 2020;15(9):e0239360.
    PMID: 32960911 DOI: 10.1371/journal.pone.0239360
    Exploiting plant extracts to form metallic nanoparticles has been becoming the promising alternative routes of chemical and physical methods owing to environmentally friendly and abundantly renewable resources. In this study, Momordica charantia and Psidium guajava leaf extract (MC.broth and PG.broth) are exploited to fabricate two kinds of biogenic silver nanoparticles (MC.AgNPs and PG.AgNPs). Phytoconstituent screening is performed to identify the categories of natural compounds in MC.broth and PG.broth. Both extracts contain wealthy polyphenols which play a role of reducing agent to turn silver (I) ions into silver nuclei. Trace alkaloids, rich saponins and other oxygen-containing compounds creating the organic corona surrounding nanoparticles act as stabilizing agents. MC.AgNPs and PG.AgNPs are characterized by UV-vis and FTIR spectrophotometry, EDS and TEM techniques. FTIR spectra indicate the presence of O-H, C = O, C-O-C and C = C groups on the surface of silver nanoparticles which is corresponded with three elements of C, O and Ag found in EDS analysis. TEM micrographs show the spherical morphology of MC.AgNPs and PG.AgNPs. MC.AgNPs were 17.0 nm distributed in narrow range of 5-29 nm, while the average size of PG.AgNPs were 25.7 nm in the range of 5-53 nm. Further, MC.AgNPs and PG.AgNPs exhibit their effectively inhibitory ability against A. niger, A. flavus and F. oxysporum as dose-dependence. Altogether, MC.AgNPs and PG.AgNPs will have much potential in scaled up production and become the promising fungicides for agricultural applications.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  3. Iqhrammullah M, Marlina, Hedwig R, Karnadi I, Kurniawan KH, Olaiya NG, et al.
    Polymers (Basel), 2020 Apr 13;12(4).
    PMID: 32294999 DOI: 10.3390/polym12040903
    The use of polymeric material in heavy metal removal from wastewater is trending. Heavy metal removal from wastewater of the industrial process is of utmost importance in green/sustainable manufacturing. Production of absorbent materials from a natural source for industrial wastewater has been on the increase. In this research, polyurethane foam (PUF), an adsorbent used by industries to adsorb heavy metal from wastewater, was prepared from a renewable source. Castor oil-based polyurethane foam (COPUF) was produced and modified for improved adsorption performance using fillers, analyzed with laser-induced breakdown spectroscopy (LIBS). The fillers (zeolite, bentonite, and activated carbon) were added to the COPUF matrix allowing the modification on its surface morphology and charge. The materials were characterized using Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and thermal gravimetry analysis (TGA), while their adsorption performance was studied by comparing the LIBS spectra. The bentonite-modified COPUF (B/COPUF) gave the highest value of the normalized Pb I (405.7 nm) line intensity (2.3), followed by zeolite-modified COPUF (Z/COPUF) (1.9), and activated carbon-modified COPUF (AC/COPUF) (0.2), which indicates the adsorption performance of Pb2+ on the respective materials. The heavy metal ions' adsorption on the B/COPUF dominantly resulted from the electrostatic attraction. This study demonstrated the potential use of B/COPUF in adsorption and LIBS quantitative analysis of aqueous heavy metal ions.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  4. Wong YH, Tan HY, Kasbollah A, Abdullah BJJ, Acharya RU, Yeong CH
    World J Exp Med, 2020 Mar 30;10(2):10-25.
    PMID: 32266125 DOI: 10.5493/wjem.v10.i2.10
    BACKGROUND: Liver cancer is the 6th most common cancer in the world and the 4th most common death from cancer worldwide. Hepatic radioembolization is a minimally invasive treatment involving intraarterial administration of radioembolic microspheres.

    AIM: To develop a neutron-activated, biodegradable and theranostics samarium-153 acetylacetonate (153SmAcAc)-poly-L-lactic acid (PLLA) microsphere for intraarterial radioembolization of hepatic tumors.

    METHODS: Microspheres with different concentrations of 152SmAcAc (i.e., 100%, 150%, 175% and 200% w/w) were prepared by solvent evaporation method. The microspheres were then activated using a nuclear reactor in a neutron flux of 2 × 1012 n/cm2/s1, converting 152Sm to Samarium-153 (153Sm) via152Sm (n, γ) 153Sm reaction. The SmAcAc-PLLA microspheres before and after neutron activation were characterized using scanning electron microscope, energy dispersive X-ray spectroscopy, particle size analysis, Fourier transform infrared spectroscopy, thermo-gravimetric analysis and gamma spectroscopy. The in-vitro radiolabeling efficiency was also tested in both 0.9% sodium chloride solution and human blood plasma over a duration of 550 h.

    RESULTS: The SmAcAc-PLLA microspheres with different SmAcAc contents remained spherical before and after neutron activation. The mean diameter of the microspheres was about 35 µm. Specific activity achieved for 153SmAcAc-PLLA microspheres with 100%, 150%, 175% and 200% (w/w) SmAcAc after 3 h neutron activation were 1.7 ± 0.05, 2.5 ± 0.05, 2.7 ± 0.07, and 2.8 ± 0.09 GBq/g, respectively. The activity of per microspheres were determined as 48.36 ± 1.33, 74.10 ± 1.65, 97.87 ± 2.48, and 109.83 ± 3.71 Bq for 153SmAcAc-PLLA microspheres with 100%, 150%, 175% and 200% (w/w) SmAcAc. The energy dispersive X-ray and gamma spectrometry showed that no elemental and radioactive impurities present in the microspheres after neutron activation. Retention efficiency of 153Sm in the SmAcAc-PLLA microspheres was excellent (approximately 99%) in both 0.9% sodium chloride solution and human blood plasma over a duration of 550 h.

    CONCLUSION: The 153SmAcAc-PLLA microsphere is potentially useful for hepatic radioembolization due to their biodegradability, favorable physicochemical characteristics and excellent radiolabeling efficiency. The synthesis of the formulation does not involve ionizing radiation and hence reducing the complication and cost of production.

    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  5. Hasan M, Gopakumar DA, Olaiya NG, Zarlaida F, Alfian A, Aprinasari C, et al.
    Int J Biol Macromol, 2020 Aug 01;156:896-905.
    PMID: 32289410 DOI: 10.1016/j.ijbiomac.2020.04.039
    Biodegradable films composed of starch and chitosan plasticized by palm oil were fabricated via a solvent casting technique. In this study, the influence of the ratio of brown rice starch and chitosan on the mechanical, thermal, antimicrobial, and morphological properties of the films was investigated. Antimicrobial films with a smooth surface and a compact structure of brown rice starch were obtained. The results showed that a higher proportion of chitosan in the polymer blends resulted in a substantial enhancement in the tensile strength (TS) and thermal stability of the film. The TS values for BRS100, BRS30CH70, BRS50CH50, BRS70CH30, and CH100 were 3.7, 15.2, 10.2, 9.3, and 8.8 MPa, respectively, and the elongation at break (EB) values of the BRS100, BRS30CH70, BRS50CH50, BRS70CH30, and CH100 samples were 39.5%, 34.7%, 7.3%, 11.5%, and 6.9%, respectively. The addition of chitosan to the brown rice starch samples resulted in a reduced water uptake of the film. The film with a balanced ratio of brown rice starch and chitosan exhibited excellent water resistance, with its water absorption being the lowest among all of the studied compositions.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  6. Akinfalabi SI, Rashid U, Arbi Nehdi I, Yaw Choong TS, Sbihi HM, Gewik MM
    R Soc Open Sci, 2020 Jan;7(1):191592.
    PMID: 32218977 DOI: 10.1098/rsos.191592
    The optimum conditions to produce palm fatty acid distillate (PFAD)-derived-methyl esters via esterification have been demonstrated with the aid of the response surface methodology (RSM) with central composite rotatable design in the presence of heterogeneous acid catalyst. The effect of four reaction variables, reaction time (30-110 min), reaction temperature (30-70°C), catalyst concentration (1-3 wt.%) and methanol : PFAD molar ratio (3 : 1-11 : 1), were investigated. The reaction time had the most influence on the yield response, while the interaction between the reaction time and the catalyst concentration, with an F-value of 95.61, contributed the most to the esterification reaction. The model had an R2-value of 0.9855, suggesting a fit model, which gave a maximum yield of 95%. The fuel properties of produced PFAD methyl ester were appraised based on the acid value, iodine value, cloud and pour points, flash point, kinematic viscosity, density, ash and water contents and were compared with biodiesel EN 14214 and ASTM D-6751 standard limits. The PFAD methyl ester was further blended with petro-diesel from B0, B3, B5, B10, B20 and B100, on a volumetric basis. The blends were characterized by TGA, DTG and FTIR. With an acid value of 0.42 (mg KOH g-1), iodine value of 63 (g.I2/100 g), kinematic viscosity of 4.31 (mm2 s-1), the PFAD methyl ester has shown good fuel potential, as all of its fuel properties were within the permissible international standards for biodiesel.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  7. Muthiah B, Muthukrishnan L, Anita Lett J, Sagadevan S, Kesavan S, Vennila S, et al.
    J Nanosci Nanotechnol, 2020 10 01;20(10):6326-6333.
    PMID: 32384982 DOI: 10.1166/jnn.2020.17897
    Biosynthesis of nanoparticles has now become a novel trend in addressing some of the environmental issues by adopting eco-friendly approaches in manoeuvring nanoparticles for various applications. Plants and micro-organisms have been the potential sources of the biological mode of synthesizing nanoparticles as part of their bioremediation process. This principle has been harnessed for synthesizing nanoparticles either extra or intracellularly. In this line of phyto-mediated synthesis, eucalyptus buds have been used for synthesizing gold nanoparticles (Au NPs) under optimized laboratory conditions. The UV-visible spectrum of the Au NPs showed typical surface plasmon resonance at 550 nm (λmax) with a crystalline phase measuring <100 nm in size and monodispersed as revealed from XRD, FESEM, and AFM analyses. The biological role of phytochemical concoction in reducing and stabilizing the Au NPs was clearly identified from FT-IR studies. The antimicrobial effect of the Au NPs against clinically important pathogens viz. Staphylococcus sp., Pseudomonas sp., Bacillus sp. and E. coli determined using the disk diffusion method showed no significant antibacterial effect at all concentrations. Cytotoxicity studies were carried using Vero and HEp-2 cell lines and the 50% inhibition concentration (IC50) was determined to be 1.25 mg and 0.625 mg/mL respectively. Au NPs with potential antimicrobial and anti-proliferative effects could found profound implications in the field of nanomedicine once the toxicity in vivo has been investigated.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  8. Jamain Z, Khairuddean M, Guan-Seng T
    Molecules, 2020 May 01;25(9).
    PMID: 32370000 DOI: 10.3390/molecules25092122
    A series of new hexasubstituted cyclotriphosphazene compounds (4a-j) consisting of two Schiff base linking units and different terminal substituents was successfully synthesized and characterized. The structures of these compounds were confirmed using Fourier Transform Infra-Red (FTIR), Nuclear Magnetic Resonance (NMR), and CHN elemental analysis. Polarized optical microscopy (POM) was used to determine their liquid-crystal behavior, which was then further confirmed using differential scanning calorimetry (DSC). Compounds 4a-i with heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxy, 4-carboxyphenyl, chloro, and nitro terminal ends, respectively, showed the liquid-crystal properties, whereas compound 4j with the amino group was found to be non-mesogenic. The attachment of an electron-donating group in 4j eventually give a non-mesogenic product. The study of the fire-retardant properties of these compounds was done using the limiting oxygen index (LOI). In this study, polyester resin (PE) was used as a matrix for moulding, and the LOI value of pure PE was 22.53%. The LOI value increased to 24.71% when PE was incorporated with 1 wt.% of hexachlorocyclotriphosphazene (HCCP), thus indicating that HCCP has a good fire-retardant properties. The result showed that all the compounds have good agreement in their LOI values. Compound 4i with a nitro terminal group gave the highest LOI value of 28.37%.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  9. Mohd Izham NZ, Yusoff HM, Ul Haq Bhat I, Endo T, Fukumura H, Kwon E, et al.
    Data Brief, 2020 Jun;30:105568.
    PMID: 32368595 DOI: 10.1016/j.dib.2020.105568
    The structural investigation of synthesized compounds can be carried out by various spectroscopic techniques. It is an important prospect in order to elucidate the structure of the desired products before being further utilized. The preparation of new p-nitro stilbene Schiff base derivatives as an electrochemical DNA potential spacer was synthesized using (E)-4-(4-nitrostyryl)aniline from Heck reaction with aldehydes in ethanolic solution. The data presented here in this article contains FTIR, UV-Vis and 1H and 13C NMR of (E)-4-(4-nitrostyryl)aniline and nitrostyryl aniline derivatives.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  10. Chua SC, Chong FK, Ul Mustafa MR, Mohamed Kutty SR, Sujarwo W, Abdul Malek M, et al.
    Sci Rep, 2020 03 03;10(1):3959.
    PMID: 32127558 DOI: 10.1038/s41598-020-60119-x
    The importance of graft copolymerization in the field of polymer science is analogous to the importance of alloying in the field of metals. This is attribute to the ability of the grafting method to regulate the properties of polymer 'tailor-made' according to specific needs. This paper described a novel plant-based coagulant, LE-g-DMC that synthesized through grafting of 2-methacryloyloxyethyl trimethyl ammonium chloride (DMC) onto the backbone of the lentil extract. The grafting process was optimized through the response surface methodology (RSM) using three-level Box-Behnken Design (BBD). Under optimum conditions, a promising grafting percentage of 120% was achieved. Besides, characterization study including SEM, zeta potential, TGA, FTIR and EDX were used to confirm the grafting of the DMC monomer chain onto the backbone of lentil extract. The grafted coagulant, LE-g-DMC outperformed lentil extract and alum in turbidity reduction and effective across a wide range of pH from pH 4 to pH 10. Besides, the use of LE-g-DMC as coagulant produced flocs with excellent settling ability (5.09 mL/g) and produced the least amount of sludge. Therefore, from an application and economic point of views, LE-g-DMC was superior to native lentil extract coagulant and commercial chemical coagulant, alum.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  11. Sagadevan S, Vennila S, Suraiya Begum SN, Wahab YA, Hamizi NAB, Marlinda AR, et al.
    J Nanosci Nanotechnol, 2020 09 01;20(9):5452-5457.
    PMID: 32331117 DOI: 10.1166/jnn.2020.17855
    Nanostructure materials are of interest in last few decades due to their unique size-dependent physio-chemical properties. In this paper, zinc oxide (ZnO) and barium doped ZnO nanodisks (NDs) were synthesized using sonochemical method and characterized by various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), UV-vis absorption and dielectric measurements. The XRD and FTIR studies confirm the crystalline nature of ZnO NDs, and the average crystallite size was found to be ~25 nm for pure ZnO and ~22 nm for Ba doped ZnO NDs. SEM study confirmed the spherical shaped ZnO NDs with average sizes in the range of 20-30 nm. The maximum absorbance was obtained in the 200-500 nm regions with a prominent peak absorbance were observed by UV-vis spectra. The corresponding band gap for ZnO NDs and Ba doped ZnO NDs were calculated using Tauc's plot and was found to be 3.12 and 3.04, respectively. The conductivity and dielectric measurements as a function of frequency have been studied.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  12. Shamsuri AA, Md Jamil SNA
    Materials (Basel), 2020 Apr 17;13(8).
    PMID: 32316400 DOI: 10.3390/ma13081885
    Polybutylene succinate (PBS)/rice starch (RS) blends were prepared via the hot-melt extrusion technique through the usage of a twin-screw extruder without and containing ionic liquid-based surfactants (ILbS). Two types of ILbS were used, specifically, 1-dodecyl-3-methylimidazolium trifluoromethanesulfonate, [C12mim][OTf] and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C12mim][NTf2] were mixed into the PBS/RS blends at the different contents (0-8 wt.%). The tensile and flexural results showed that the blends containing ILbS have a high tensile extension and tensile energy compared to the blend without ILbS. The blends containing ILbS also have a high flexural extension compared with the blend without ILbS. The blends containing [C12mim][NTf2] have a significant improvement in the tensile energy (up to 239%) and flexural extension (up to 17%) in comparison with the blends containing [C12mim][OTf]. The FTIR spectra demonstrated that the presence of ILbS in the blends generated the intermolecular interactions (ion-dipole force and hydrophobic-hydrophobic interaction) between PBS and RS. The DSC results exhibited that the melting points of the prepared blends are decreased with the addition of ILbS. However, the TGA results showed that the thermal decomposition of the blends containing ILbS are higher than the blend without ILbS. The values of decomposition temperature were 387.4 °C, 381.8 °C, and 378.6 °C of PBS/RS-[C12mim][NTf2], PBS/RS-[C12mim][OTf], and PBS/RS, respectively. In conclusion, the ILbS could significantly improve the physicochemical properties of the PBS/RS blends by acting as a compatibilizer.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  13. Syed Ibrahim GP, Isloor AM, Ismail AF, Farnood R
    Sci Rep, 2020 04 23;10(1):6880.
    PMID: 32327672 DOI: 10.1038/s41598-020-63356-2
    In this paper, novel zwitterionic graphene oxide (GO) nanohybrid was synthesized using monomers [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) and N,N'-methylenebis(acrylamide) (MBAAm) (GO@poly(SBMA-co-MBAAm), and incorporated into polysulfone (PSF) hollow fiber membrane for the effectual rejection of dye from the wastewater. The synthesized nanohybrid was characterized using FT-IR, PXRD, TGA, EDX, TEM and zeta potential analysis. The occurrence of nanohybrid on the membrane matrix and the elemental composition were analyzed by XPS. The as-prepared tight ultrafiltration hollow fiber membrane exhibited high rejection of reactive black 5 (RB-5, 99%) and reactive orange 16 (RO-16, 74%) at a dye concentration of 10 ppm and pure water flux (PWF) of 49.6 L/m2h. Fabricated nanocomposite membranes were also studied for their efficacy in the removal of both monovalent (NaCl) and divalent salts (Na2SO4). The results revealed that the membrane possesses complete permeation to NaCl with less rejection of Na2SO4 (<5%). In addition, the nanocomposite membrane revealed outstanding antifouling performance with the flux recovery ratio (FRR) of 73% towards bovine serum albumin (BSA). Therefore, the in-house prepared novel nanocomposite membrane is a good candidate for the effective decolorization of wastewater containing dye.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  14. Jawad AH, Abdulhameed AS, Reghioua A, Yaseen ZM
    Int J Biol Macromol, 2020 Nov 15;163:756-765.
    PMID: 32634511 DOI: 10.1016/j.ijbiomac.2020.07.014
    In this research, an attempt to develop zwitterion composite adsorbent is conducted by modifying chitosan (CHS) with a covalent cross-linker (epichlorohydrin, ECH) and an aluminosilicate mineral (zeolite, ZL). The zwitterion composite adsorbent of chitosan-epichlorohydrin/zeolite (CHS-ECH/ZL) is performed multifunctional tasks by removing two structurally different cationic (methylene blue dye, MB), and anionic (reactive red 120 dye, RR120) dyes from aqueous solutions. The surface property, crystallinity, morphology, functionality, and charge of the CHS-ECH/ZL are analyzed using BET, XRD, SEM, FTIR, and pHpzc, analyses, respectively. The influence of pertinent parameters namely CHS-ECH/ZL dosage (0.02-0.5 g), solution pH (4-10), temperature (303-323K), initial dye concentration (30-400 mg/L), and contact time (0-600 min) on the MB and RR120 removal are tested. The research findings revealed that the adsorption isotherm at equilibrium well explained in according to the Freundlich isotherm model, and the recorded adsorption capacities of CHS-ECH/ZL are 156.1 and 284.2 mg/g for MB and RR120 respectively at 30 °C. The mechanism of MB and RR120 adsorption onto the CHS-ECH/ZL indicates various types of interactions namely, electrostatic interaction, hydrogen bonding, and Yoshida H-bonding in addition to n-π interaction. Overall, this research introduces CHS-ECH/ZL composite as an eco-friendly zwitterion adsorbent with good applicability towards the two structurally different cationic and anionic dyes from aqueous environment.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  15. Rayung M, Aung MM, Su'ait MS, Chuah Abdullah L, Ahmad A, Lim HN
    ACS Omega, 2020 Jun 23;5(24):14267-14274.
    PMID: 32596563 DOI: 10.1021/acsomega.9b04348
    Biobased polymers are useful materials in substituting conventional petroleum-derived polymers because of their good properties, ready availability, and abundance in nature. This study reports a new jatropha oil-based gel polymer electrolyte (GPE) for use in dye-sensitized solar cells (DSSCs). The GPE was prepared by mixing jatropha oil-based polyurethane acrylate (PUA) with different concentrations of lithium iodide (LiI). The GPE was characterized by infrared spectroscopy, thermal analysis, lithium nuclear magnetic resonance analysis, electrochemical analysis, and photocurrent conversion efficiency. The highest room-temperature ionic conductivity of 1.88 × 10-4 S cm-1 was obtained at 20 wt % of LiI salt. Additionally, the temperature-dependent ionic conductivity of the GPE exhibited Arrhenius behavior with an activation energy of 0.42 eV and a pre-exponential factor of 1.56 × 103 S cm-1. The electrochemical stability study showed that the PUA GPE was stable up to 2.35 V. The thermal stability of the gel electrolyte showed an improvement after the addition of the salt, suggesting a strong intermolecular interaction between PUA and Li, which leads to polymer-salt complexation, as proven by Fourier transform infrared spectroscopy analysis. A DSSC has been assembled using the optimum ionic conductivity gel electrolyte which indicated 1.2% efficiency under 1 sun condition. Thus, the jatropha oil-based GPE demonstrated favorable properties that make it a promising alternative to petroleum-derived polymer electrolytes in DSSCs.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  16. Chang YS, Au PI, Mubarak NM, Khalid M, Jagadish P, Walvekar R, et al.
    Environ Sci Pollut Res Int, 2020 Sep;27(26):33270-33296.
    PMID: 32529626 DOI: 10.1007/s11356-020-09423-7
    Two superior adsorbents, namely bentonite and graphene oxide (GO), were hybridised to study the removal of copper and nickel ions from synthetic and industrial wastewater. The as-synthesised GO, bentonite/GO and bentonite were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and N2 adsorption-desorption analysis. The factors influencing the adsorption behaviours including contact time, initial solution pH, ionic strength, initial concentration of metal ions, temperature and adsorbent dosage were systematically investigated by batch equilibrium method. The adsorption equilibrium for copper and nickel onto bentonite was attained in 90 min while equilibrium was reached in 60 min on bentonite/GO. The adsorption of copper and nickel was pH-dependent in the range from pH 2 to pH 7 and from pH 2 to pH 8. Pseudo-first-order kinetic model excellently described the adsorption of copper and nickel onto bentonite and bentonite/GO. The equilibrium adsorption data was well described by the Langmuir isotherm model and the maximum adsorption capacity was 248.9 mg/g, 558.4 mg/g, 215.8 mg/g and 402.5 mg/g for bentonite-copper, bentonite/GO-copper, bentonite-nickel and bentonite/GO-nickel adsorption systems, respectively. The bentonite/GO composite exhibited a higher adsorption capacity of both cations from synthetic wastewater than pure bentonite owning to the synergistic effect between bentonite and GO. In all adsorption studies, copper was more efficiently removed than nickel due to its higher tendency to form bond with adsorbent surfaces. The adsorption of copper and nickel on bentonite/GO was mainly due to cation exchange, intermolecular and electrostatic interactions and physisorption dominated the adsorption processes. The practical application of bentonite/GO on adsorption of copper was investigated using real wastewater and its removal efficiency was beyond 98%. The excellent adsorption performances of composites for the copper and nickel removal from wastewater demonstrated its significant potential for pollution mitigations.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  17. Baby R, Hussein MZ
    Materials (Basel), 2020 Jun 09;13(11).
    PMID: 32526876 DOI: 10.3390/ma13112627
    Heavy metal ion contamination in water poses a significant risk to human health as well as to the environment. Millions of tons of agricultural wastes are produced from oil palm plantations which are challenging to manage. In this study, we converted palm kernel shells (PKS) from a palm oil plantation into activated carbon (AC) having a surface area of 1099 m2/g using phosphoric acid as an activator. The prepared material was characterized using BET, XRD, Raman, FESEM and FTIR analyses. The AC was applied for the treatment of heavy-metal-contaminated water, and different parameters; the pH, adsorbent dosage, contact time and metal ion concentrations were varied to determine the optimal conditions for the metal ion adsorption. Different kinetic models; the zeroth, first-order and second-order, and Freundlich and Langmuir isotherm models were used to determine the mechanism of metal ion adsorption by the AC. Under the optimized conditions, Cr6+ and Pb2+ were removed completely, while Zn2+ and Cd2+ were more than 80% removed. This is a greener approach in which an agricultural waste, PKS is converted into a useful product, activated carbon and subsequently applied for the treatment of heavy metal-contaminated water.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  18. Rasheed M, Jawaid M, Karim Z, Abdullah LC
    Molecules, 2020 Jun 18;25(12).
    PMID: 32570929 DOI: 10.3390/molecules25122824
    Bamboo fibers are utilized for the production of various structures, building materials, etc. and is of great significance all over the world especially in southeast Asia. In this study, the extraction of microcrystalline cellulose (MCC) was performed using bamboo fibers through acid hydrolysis and subsequently different characterizations were carried out using various advanced techniques. Fourier transform infrared (FTIR) spectroscopy analysis has indicated the removal of lignin from MCC extracted from bamboo pulp. Scanning Electron Microscopy (SEM) revealed rough surface and minor agglomeration of the MCC. Pure MCC, albeit with small quantities of impurities and residues, was obtained, as revealed by Energy Dispersive X-ray (EDX) analysis. X-ray diffraction (XRD) indicates the increase in crystallinity from 62.5% to 82.6%. Furthermore, the isolated MCC has slightly higher crystallinity compared to commercial available MCC (74%). The results of thermal gravimetric analysis (TGA) demonstrate better thermal stability of isolated MCC compared to its starting material (Bamboo fibers). Thus, the isolated MCC might be used as a reinforcing element for the production of green composites and it can also be utilized as a starting material for the production of crystalline nanocellulose in future.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  19. Rahman ML, Fui CJ, Sarjadi MS, Arshad SE, Musta B, Abdullah MH, et al.
    Environ Sci Pollut Res Int, 2020 Sep;27(27):34541-34556.
    PMID: 32557073 DOI: 10.1007/s11356-020-09462-0
    A waste material known as palm oil empty fruit bunch (EFB) is used as a source of cellulose for the development of polymeric materials for the removal of metal ions from industrial wastewater. A poly(acrylonitrile)-grafted palm cellulose copolymer was synthesized by a conventional free radical initiating process followed by synthesis of a poly(amidoxime) ligand by oximation reaction. The resulting products were characterized by FT-IR, FE-SEM, EDX, TGA, DSC, and XPS. The poly(amidoxime) ligand was used to coordinate with and extract a series of transition metal ions from water samples. The binding capacity (qe) of the ligand with the metal ions such as copper, iron, cobalt, nickel, and lead were 260, 210, 168, 172, and 272 mg g-1, respectively at pH 6. The adsorption process followed the pseudo-first-order kinetic model (R2 > 0.99) and as well as the Freundlich isotherm model (R2 > 0.99) indicating the occurrence of a multi-layer adsorption process in the amidoxime ligand adsorbent. Results from reusability studies show that the ligand can be recycled for at least 10 cycles without any significant losses to its initial adsorption capacity. The synthesized polymeric ligand was shown to absorb heavy metals from electroplating wastewater with up to 95% efficiency.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  20. Jamain Z, Khairuddean M, Guan-Seng T
    Int J Mol Sci, 2020 Jun 16;21(12).
    PMID: 32560033 DOI: 10.3390/ijms21124267
    Two series of new hexasubstituted cyclotriphosphazene derivatives were successfully synthesized and characterized. These derivatives are differentiated by two types of linking units in the molecules such as amide-azo (6a-j) and azo-azo (8a-j). The homologues of the same series contain different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxyl, carboxyl, chloro, nitro, and amino groups. All the intermediates and final compounds were characterized using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and Carbon, Hydrogen, and Nitrogen (CHN) elemental analysis. Liquid crystal properties for all compounds were determined using polarized optical microscope (POM). It was found that only intermediates 2a-e with nitro and alkoxyl terminal chains showed a smectic A phase. All the final compounds with alkoxyl substituents are mesogenic with either smectic A or C phases. However, other intermediates and compounds were found to be non-mesogenic. The study on the fire retardancy of final compounds was determined using limiting oxygen index (LOI) method. The LOI value of pure polyester resin (22.53%) was increased up to 24.71% after treating with 1 wt% of hexachlorocyclotriphosphazene (HCCP). Moreover, all the compounds gave positive results on the LOI values and compound 6i with the nitro terminal substituent showed the highest LOI value of 27.54%.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
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