Displaying publications 41 - 60 of 1001 in total

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  1. Extraction and characterization of Pectin from Dragon fruit (Hylocereus polyrhizus) using various extraction conditions
    Norazelina Sah Mohd Ismail, Nazaruddin Ramli, Norziah Mohd Hani, Zainudin Meon
    Sains Malaysiana, 2012;41:41-45.
    The extraction of pectin from dragon fruit (Hylocereus polyrhizus) peels under three different extraction conditions was identified as an alternative source of commercial pectin. In this work, dried alcohol-insoluble residues (AIR) of dragon fruit peels were treated separately with 0.25% ammonium oxalate/oxalic acid at a pH of 4.6 at 85oC; 0.03 M HCl at a pH of 1.5 at 85oC; and de-ionized water at 75oC. The pectin obtained from these methods was compared in terms of yield, physicochemical properties and chemical structure. Fourier Transform Infrared Spectroscopy (FTIR) was used in the identification of dragon fruit pectins. The results showed that the pectin yield (14.96-20.14% based on dry weight), moisture content (11.13-11.33%), ash content (6.88-11.55%), equivalent weight (475.64-713.99), methoxyl content (2.98-4.34%), anhydrouronic acid (45.25-52.45%) and the degree of esterification (31.05-46.96%) varied significantly (p < 0.05) with the various extraction conditions used. Pectin extracted with ammonium oxalate gave the highest yield of pectin, with high purity and low ash content. Based on the value of methoxyl content and the degree of esterification, dragon fruit pectin can be categorized as low-methoxyl pectin.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  2. Penghasilan poliol minyak sawit olein secara hidrolisis selanjar dan berkelompok
    Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2013;42:1121-1129.
    Sebatian poliol minyak sawit olein (di-hidroksi-POo) (70% hasil) disintesis melalui pembukaan gelang oksirana minyak sawit olein terepoksida (EPOo) secara hidrolisis selanjar dan berkelompok. Hasil optimum pembukaan gelang oksirana (97.2%) bagi kedua-dua tindak balas selama 90 min (tindak balas selanjar) dan 75 min (tindak balas berkelompok) dengan menggunakan mangkin asid perklorik 3% v/wt. Spektrum transformasi Fourier inframerah (FTIR) di-hidroksi-POo menunjukkan kehadiran puncak lebar getaran regangan kumpulan hidroksil pada nombor gelombang 3429 cm-1, menunjukkan sebatian poliol telah berjaya dihasilkan. Spektrum resonan magnetik nukleus-karbon (13C-NMR) di-hidroksi-POo telah menunjukkan kehadiran puncak karbon yang terikat dengan kumpulan hidroksil (74.5 ppm). Spektrum resonan magnetik nukleus-proton (1H-NMR) di-hidroksi-POo telah menunjukkan kehadiran puncak proton yang terikat pada karbon poliol (3.4 ppm) dan proton pada kumpulan hidroksil (4.6 ppm). Kelikatan kinematik produk poliol (nilai hidroksil sebanyak 110.7 mgKOH/g minyak) adalah 1435.2 cSt (40oC) dan 55.2 cSt (100oC) dengan indeks kelikatan 78.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  3. Optical properties of lithium borate glass (Li2O)x (B203)1_x
    Halimah M, Chiew W, Sidek H, Daud W, Wahab Z, Khamirul A, et al.
    Sains Malaysiana, 2014;43:899-902.
    A series of (Li20)x(B203)1-x has been synthesized with mole fraction x=0.10, 0.15,020,025 and 0.30 mol% using melt quenching method. The structure of the glass system was determined by FTIR and X-ray diffraction. The density and molar volume were determined and the density increases with Li20 content whereas molar volume decreases with Li20. Refractive index of glass samples were measured by ellipsometer. Refractive index increases with increase of Li20. The absorption spectra of the studied glass showed that position of fundamental absorption edge shifts to longer wavelength with Li20. Optical band gap varies from 0.10 to 222 eV and Urbach energy varies from 2.91 to 1.55 eV. The variation in optical band gap and Urbach energy were due to the variation in the glass structure.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  4. Study of Structural and Luminescence Properties of Lead Lithium Borophosphate Glass System Doped with Ti Ions
    Leow T, Leong P, Eeu T, Ibrahim Z, Hussin R
    Sains Malaysiana, 2014;43:929-934.
    Study of a series of lead lithium borophosphate glass samples was performed to determine the structural and luminescence properties. The glass samples containing the composition of 20Pb0-xLi20-30B 20 3-(50-x)P 20 5-2TiO 2 (where x = 0, 5, 10, 15, 20) system were prepared using melt-quenching technique. The Pb0-Li20-B 20 3-P20 5-Ti0 2 samples were investigated for structural properties using Fourier transform infrared and photoluminescence spectroscopy for studies of luminescence properties. The results from FTIR showed the presence of trigonal and tetrahedral PO4' PO3, BO4 and B03 groups within the host network structure. The samples exhibit luminescence emission centered at 420, 482 and 496 nm when excited at 300 nm wavelength. The emission peak at 420 nm were assigned to F center emission and charge-transfer transition of Ti4+ ions. The results showed that emission intensity was dependent on lithium contents in Ti-doped lead lithium borophosphate glass composition.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  5. Effects of season on the yield and quality of extracts from Gracilaria changii (Gracilariaceae, Rhodophyta)
    Sasidharan S, Darah I, Jain K
    Sains Malaysiana, 2009;38.
    The effect of season on yield and quality of organic solvent extracts from Gracilaria changii was determined. The sustainability of the bioactive compound of G. changii from Malaysia was investigated by using the TLC and FTIR standards methods. Studies was carried out to examine the sustainability of the bioactive compound in the various extract obtained from G. changii collected from Pantai Morib, Beach Selangor Malaysia on bimonthly for a period of one year in 2003. This study revealed that the bioactive compounds was present all over the year but with different quantities. In general the variation in yield or quantities of bioactive compound was related to environment. G. changii can be considered a candidate for drug development since it retained the number of bioactive compound.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  6. Effect of cellulose nanocrystals content and ph on swelling behaviour of gelatin based hydrogel
    Ooi SY, Ishak Ahmad, Mohd Cairul Iqbal Mohd Amin
    Sains Malaysiana, 2015;44:793-799.
    In this research, a novel method was performed to obtain hydrogel with superior thermal stability by incorporation
    of cellulose nanocrystals (CNC) into gelatin based hydrogel. Glutaraldehyde was used as cross-linker due to its high
    chemical reactivity towards NH2
    group on gelatin. Different ratio of gelatin/CNC hydrogel was produced in order to study
    the effects of CNC towards the swelling behaviour and thermal stability of gelatin based hydrogel. The obtained hydrogel
    was subjected to Fourier transform infrared (FTIR) to verify that gelatin had been cross-linked, swelling test with different
    pH for swelling behaviour and thermogravimetric analysis (TGA) for thermal stability. The presence of C=N stretching
    group in the FTIR spectrum for gelatin/CNC hydrogel indicated that the cross-linking reaction between gelatin monomer
    had been successfully carried out. The hydrogel showed impressive pH sensitivity and maximum swelling was obtained
    at pH3. The TGA results clearly showed that the incorporation of CNC into gelatin was able to produce hydrogel with
    higher thermal stability compare to neat gelatin.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  7. Sintesis dan sifat termal natrium kanji sulfat dioscorea pentaphylla
    Elmi Sharlina MS, Azwan Mat Lazim, Yaacob WA
    Sains Malaysiana, 2017;46:1549-1555.
    Kanji Dioscorea pentaphylla telah diubah suai dengan pensulfatan dan peneutralan bagi menghasilkan natrium
    kanji sulfat. Tindak balas pensulfatan dilakukan dengan asid sulfurik dalam etanol dan air pada suhu 0o
    C. Darjah
    penukargantian dikira berdasarkan peratus karbon dan sulfur yang ditentukan menggunakan penganalisis unsur CHNS.
    Natrium kanji sulfat yang mempunyai darjah penukargantian dan peratus nisbah berat hasil yang tinggi dipilih dan
    dicirikan dengan spektrum transformasi Fourier inframerah (FT-IR) dan profil pembelauan sinar-X (XRD). Kehadiran
    dua puncak getaran regangan C-O-S dan S=O dalam spektrum FT-IR dan puncak berbeza yang terhasil dalam corak
    difraktogram XRD membuktikan tindak balas berlaku pada struktur kanji. Sifat termal juga ditentukan dengan kalorimeter
    pengimbas pembezaan (DSC) dan analisis termogravimetri (TGA). Natrium kanji sulfat yang dihasilkan mempunyai
    kestabilan termal yang baik kerana mempunyai suhu penguraian pada 265o
    C. Natrium kanji sulfat ini sesuai dijadikan
    bahan tambahan dalam penghasilan hidrogel, organogel dan filem dengan sifat anionik kerana degradasi tidak terjadi
    di bawah suhu ini.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  8. Synthesis and structural characterization of 6-(N-Methyl-pyridin-2-ylcarbamoyl)-pyridine-2-carboxylic Acid Methyl Ester Isomers
    Maisara Abdul Kadir, Nafisah Mansor, Uwaisulqarni M. Osman
    Sains Malaysiana, 2017;46:725-731.
    A series of monoamide isomers have been successfully synthesised and characterised using combination of common spectroscopic techniques such Fourier Transform Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR) and Ultraviolet-visible (UV-vis). The monoamide compounds namely 6-(3-methyl-pyridin-2-ylcarbamoyl)-pyridine2-carboxylic acid methyl ester (L1), 6-(4-methyl-pyridin-2-ylcarbamoyl)-pyridine-2-carboxylic acid methyl ester (L2), 6-(5-methyl-pyridin-2-ylcarbamoyl)-pyridine-2-carboxylic acid methyl ester (L3) and 6-(6-methyl-pyridin-2ylcarbamoyl)-pyridine-2-carboxylic acid methyl ester (L4) were prepared from reaction between 6-(methoxycarbonyl) pyridine-2-carboxylic acid with 2-amino-N-methylpyridine (where N = 3, 4, 5 and 6) by using acyl chloride reaction. In this present studies, the synthesis and characterization of these compounds are discussed along with the inductive effects contributed by methyl substituted groups at the pyridine ring.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  9. Fulltext Synthesis and Thermal Properties of Resorcinol-Furfural Thermosetting Resin
    Liu J, Xuan D, Chai J, Guo D, Huang Y, Liu S, et al.
    ACS Omega, 2020 May 05;5(17):10011-10020.
    PMID: 32391489 DOI: 10.1021/acsomega.0c00365
    A mild and effective synthesis of resorcinol-furfural (RF) thermosetting resin was proposed with ethanol as a distinctive solvent, which, as a usually neglected factor, was shown to not only help form a homogeneous reaction system but also observably reduce the energy barriers between the early intermediates and transition states in addition reactions by explicit solvent effects, drawn from theoretical calculation conclusions. Besides, the para-additions on aromatic rings were more dominant than ortho-additions with the same reactants, which affected the final link types of monomers verified by Fourier transform infrared spectroscopy and two-dimensional nuclear magnetic resonance tests. The prepared resin can be assigned to a relatively fast gel speed and a high residual mass (65.25%) after pyrolysis in a N2 atmosphere by adjusting the molar ratios of F to R, and the curing of that was a complex reaction, with a curing temperature around 149 °C and an activation energy of about 49.11 kJ mol-1 obtained by the Kissinger method.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  10. Fulltext Investigation of attributes of bourbon oil and cobalt nitrate constituted electrospun nanoscaffolds for blood compatibility and in vitro bone formation
    Jaganathan SK, Mani MP
    An Acad Bras Cienc, 2021;93(4):e20201140.
    PMID: 34705943 DOI: 10.1590/0001-3765202120201140
    This work aims to fabricate scaffold using polyurethane (PU) integrated with bourbon oil (BB) and cobalt nitrate (CoNO3) using the electrospinning technique. Morphological investigation signified a fall in fibre diameter for the PU/BB and PU/BB/CoNO3 nanocomposite than the PU. Spectral analysis indicated that BB and CoNO3 were added within the PU matrix. Wettability analysis insinuated an increase in the hydrophobic nature of the PU/BB than the PU. PU/BB/CoNO3 turned to be hydrophilic due to the integration of CoNO3 in the polymer matrix. Mechanical testing of PU/BB and PU/BB/CoNO3 indicated an increase in the tensile strength of the fabricated composites. Atomic force microscopy (AFM) portrayed the reduction in the roughness of the PU/BB and PU/BB/CoNO3 compared to the PU. The coagulation studies invariably documented the improved anticoagulant behaviour and less toxic nature of the PU/BB and PU/BB/CoNO3 in comparison with the PU. Further, bone mineralization testing revealed the enhanced apatite formation of the nanocomposite. Nanocomposite scaffolds with the fore-mentioned properties hold good potential for bone tissue engineering.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  11. L-cysteine capped silver nanoparticles as chiral recognition sensor for ketoprofen enantiomers
    Obaid A, Mohd Jamil AK, Saharin SM, Mohamad S
    Chirality, 2021 11;33(11):810-823.
    PMID: 34486177 DOI: 10.1002/chir.23354
    A simple, inexpensive but effective approach for visual chiral recognition of ketoprofen enantiomers was developed using L-cysteine capped silver nanoparticles (L-Cys-AgNPs) as a colorimetric sensor. Upon the addition of R-ketoprofen to L-Cys-AgNPs, rapid aggregation occurred, and the solution changed color from yellow to green. However, the presence of S-ketoprofen did not induce any color change. The results were characterized using UV-Vis, FESEM, FT-IR, SERS, and zeta potential measurements. The chiral assay described in this work is easily distinguished with the naked eyes or using a UV-Vis spectrometer. The sensor revealed a good linear response to ketoprofen enantiomers in the concentration range of 8.33-33.3 μM with a detection limit of 4.52 μM and relative standard deviation of 3.73%. The proposed method was utilized for the determination of ketoprofen racemic mixtures in water samples and commercial tablets. The method excels by its simplicity, low cost, and good availability of materials.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  12. Biodiesel synthesis from Prunus bokhariensis non-edible seed oil by using green silver oxide nanocatalyst
    Dawood S, Ahmad M, Zafar M, Asif S, Klemeš JJ, Bokhari A, et al.
    Chemosphere, 2022 Mar;291(Pt 2):132780.
    PMID: 34767846 DOI: 10.1016/j.chemosphere.2021.132780
    The present work investigates the proficiency of green silver oxide nanocatalyst synthesised from Monotheca buxifolia (Falc.) Dcne. leaves extract, and their application for biodiesel synthesis from novel Prunus bokhariensis seed oil (non-edible). The seed oil content of 55% and FFA content of 0.80 mg KOH/g were reported. Several analytical tools (EDX, FT-IR, SEM and XRD) were used to characterise the Ag2O nanocatalyst. Maximum (89%) FAME yield of the PBSOB (Prunus bokhariensis seed oil biodiesel) was achieved at ambient transesterification conditions i.e. 3.5 wt% nanocatalyst loading, 2.5 h reaction time, 130 °C of reaction temperature and 12:1 alcohol to oil ratio. The synthesised PBSOB was additionally characterised by analytical methods like, GC-MS and FT-IR. The different aspects of fuel were identified i.e. flash point (84 °C), kinematic viscosity (4.01 cSt @ 40 °C), sulphur content (0.0003 wt %), density (0.853 kg/L) and acid number (0.167 mg KOH/g). All the above properties were verified and agreed well with biodiesel international standards (European Union (14214), China GB/T (20828) and ASTM (6751, 951). In general, Prunus bokhariensis seed oil and Ag2O nanocatalyst seem to be remarkably active, cheap and stable candidates for the biodiesel industry in future.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  13. Fulltext Effects of xanthan gum and HPMC on physicochemical and microstructure properties of sponge cakes during storage
    Noorlaila A, Hasanah HN, Yusoff A, Sarijo SH, Asmeda R
    J Food Sci Technol, 2017 Oct;54(11):3532-3542.
    PMID: 29051648 DOI: 10.1007/s13197-017-2810-6
    The effects of xanthan gum (XG) and hydroxypropyl methylcellulose (HPMC) in sponge cakes were studied. Hydrocolloids enhanced the thickening effect in batter that affected the textural attributes of sponge cakes. During storage, the structural changes in XG-cake resulted in higher hardness compared to HPMC-cake. Similar to XG, HPMC also contributed moistness to cake. The moisture loss of cake containing XG was slower than HPMC-cake. FTIR study showed absorption of OH at region of 3600-2900 cm-1 that explained the strong interaction of water in cake containing XG compared to other cake formulations.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  14. Fulltext Green synthesis and characterization of UKMRC-8 rice husk-derived mesoporous silica nanoparticle for agricultural application
    Dorairaj D, Govender N, Zakaria S, Wickneswari R
    Sci Rep, 2022 Nov 23;12(1):20162.
    PMID: 36424408 DOI: 10.1038/s41598-022-24484-z
    Agriculture plays a crucial role in safeguarding food security, more so as the world population increases gradually. A productive agricultural system is supported by seed, soil, fertiliser and good management practices. Food productivity directly correlates to the generation of solid wastes and utilization of agrochemicals, both of which negatively impact the environment. The rice and paddy industry significantly adds to the growing menace of waste management. In low and middle-income countries, rice husk (RH) is an underutilized agro-waste discarded in landfills or burned in-situ. RH holds enormous potential in the development of value-added nanomaterials for agricultural applications. In this study, a simple and inexpensive sol-gel method is described to extract mesoporous silica nanoparticles (MSNs) from UKMRC8 RH using the bottom-up approach. RHs treated with hydrochloric acid were calcinated to obtain rice husk ash (RHA) with high silica purity (> 98% wt), as determined by the X-ray fluorescence analysis (XRF). Calcination at 650 °C for four hours in a box furnace yielded RHA that was devoid of metal impurities and organic matter. The X-ray diffraction pattern showed a broad peak at 2θ≈20-22 °C and was free from any other sharp peaks, indicating the amorphous property of the RHA. Scanning electron micrographs (SEM) showed clusters of spherically shaped uniform aggregates of silica nanoparticles (NPs) while transmission electron microscopy analysis indicated an average particle size of Fourier transform infrared (FT-IR) spectra showed peaks at 796.4 cm-1 and 1052 cm-1 corresponding to O-Si-O symmetric stretching vibration and O-Si-O asymmetric stretching, respectively. The Brunauer-Emmet-Teller (BET) analysis indicated an average pore size = 8.5 nm while the specific surface area and the pore volume were 300.2015 m2/g and 0.659078 cm3/g, respectively. In conclusion, agrowaste-derived MSN was synthesized using a simple and economical sol-gel method without the addition of surfactant reagents for controlled formation at the structural level. Owing to the MSNs' excellent physical properties, the method established herein, could be used singly (without any modifications) for the functionalization of a myriad of agrochemicals.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  15. Angiotensin converting enzyme (ACE) inhibitors activity from purified compounds Fructus Phaleria macrocarpa (Scheff) Boerl
    Eff ARY, Huri HZ, Radji M, Mun'im A, Suyatna FD, Eden Y
    BMC Complement Med Ther, 2023 Feb 20;23(1):56.
    PMID: 36803524 DOI: 10.1186/s12906-023-03889-x
    BACKGROUND: Mahkota Dewa [Phaleria macrocarpa (Scheff) Boerl.] fruit in vitro and in- vivo can decrease and prevent elevation of the blood pressure, lower plasma glucose levels, possess an antioxidant effect, and recover liver and kidney damage in rats. This study aimed to determine the structure and inhibitory activity of angiotensin-converting enzyme inhibitors (ACE) from the Mahkota Dewa fruit.

    METHODS: The fruit powder was macerated using methanol and then partitioned by hexane, ethyl acetate, n-butanol, and water. The fractions were chromatographed on the column chromatography and incorporated with TLC and recrystallization to give pure compounds. The structures of isolated compounds were determined by UV-Visible, FT-IR, MS, proton (1H-NMR), carbon (13C-NMR), and 2D-NMR techniques encompassing HMQC and HMBC spectra. The compounds were evaluated for their ACE inhibitory activity, and the strongest compound was determined by the kinetics enzyme inhibition.

    RESULTS: Based on the spectral data, the isolated compounds were determined as 6,4-dihydroxy-4-methoxybenzophenone-2-O-β-D-glucopyranoside (1), 4,4'-dihydroxy-6-methoxybenzophenone-2-O-β-D-glucopyranoside (2) and mangiferin (3). IC50 values of the isolated compounds 1, 2 and 3 were 0.055, 0.07, and 0.025 mM, respectively.

    CONCLUSION: The three compounds have ACE inhibitor and mangiferin demonstrated the best ACE inhibitory activity with competitive inhibition on ACE with the type of inhibition kinetics is competitive inhibition.

    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  16. Fabrication, characterization, and application of light weight thermal insulation material from combined buffing dust and plaster of paris for construction industry
    Ulfat W, Mohyuddin A, Amjad M, Othman MHD, Gikas P, Kurniawan TA
    J Environ Manage, 2023 Dec 01;347:119129.
    PMID: 37778073 DOI: 10.1016/j.jenvman.2023.119129
    Buffing dust, generated from tannery industries, is a source of air pollution in Pakistan. Valorization of the waste into another useful material is important to deal with the environmental pollution, while reducing waste disposal costs in landfills. To demonstrate its technological strength, this work fabricates a thermal insulation material made of plaster of Paris and the buffing dust (from tanning waste) in the form of a composite with superior mechanical properties and low thermal conductivity. Buffing dust with concentrations ranging from 5 to 20% (w/w) were loaded in the composite. The samples synthesized were made slurry of plaster of Paris, buffing dust, and water at ambient temperature. The physico-mechanical properties of composite were analyzed. It was found that the composite had better thermal insulation properties than the panels of the plaster of Paris. Its thermal conductivity was reduced to 15% after adding buffing dust (20% w/w). All the materials had physico-chemical properties like tensile strength (0.02 MPa and 0.06 MPa), density (700-400 kg/m3), water absorption (5.2-8.6%) and thermal conductivity (0.17000-0.09218 W/m-K). Thermogravimetric analysis showed that the material was thermally stable at temperatures ranging from 145 to 177 °C, while FT-IR results revealed that the composite contained O-H, N-H, and CO functional groups. SEM analysis displayed that the composite's homogeneity was reduced with low voids due to buffing dust addition, while EDX analysis showed that the composite contained 23.62% of S, 26.76% of Ca, 49.2% of O and 0.42% of C. This implies that buffing dust could be recycled to manufacture heat insulation materials for construction sector to reduce air pollution, while minimizing energy consumption. By integrating the buffing dust from tanning waste and the plaster of Paris as a composite for construction sector, this work promotes the recycling of unused waste, while saving public funds. Instead of paying landfill fees and polluting soil, the waste may be recycled at lower cost, while reducing environmental damage.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  17. Biochar and activated carbon derived from oil palm kernel shell as a framework for the preparation of sustainable controlled release urea fertiliser
    Vejan P, Abdullah R, Ahmad N, Khadiran T
    Environ Sci Pollut Res Int, 2023 Mar;30(13):38738-38750.
    PMID: 36585594 DOI: 10.1007/s11356-022-24970-x
    The oil palm kernel shell biochar (OPKS-B) and oil palm kernel shell activated carbon (OPKS-AC) were used as a framework to entrap urea using adsorption method. Batch adsorption studies were performed to gauge the influence of contact time on the adsorption of urea onto both OPKS-B and OPKS-AC. To evaluate the physicochemical traits of the studied materials, energy dispersive X-ray spectrometer (EDS), N2-sorption, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), elemental analysis, differential thermal gravity (TG/DTG) and thermal gravity were applied. Result shows OPKS-AC has a better sorption capacity for urea compared to OPKS-B. The Langmuir isotherm model better justified the sorption isotherms of urea. For the adsorption process for both OPKS-B and OPKS-AC, the pseudo-second-order kinetic model was picked as it best fitted the experimental sorption outcome with the superior R2 values of > 65.1% and > 74.5%, respectively. The outcome of the experiments showcased that the maximum monolayer adsorption capacity of the OPKS-AC towards urea was 239.68 mg/g. OPKS-AC has showed promising attributes to be picked as an organic framework in the production of controlled release urea fertiliser for a greener and environmentally friendly agricultural practices.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  18. CO2 adsorption and CO2/CH4 separation using fibrous amine-containing adsorbents: isothermal, kinetic, and thermodynamic behaviours
    Mohamad NA, Nasef MM, Abdullah TAT, Ahmad A, Ting TM
    Environ Sci Pollut Res Int, 2023 Nov;30(55):116906-116920.
    PMID: 37121947 DOI: 10.1007/s11356-023-26913-6
    A series of fibrous aminated adsorbents for CO2 adsorption were prepared by covalent incorporation of poly (glycidyl methacrylate) (PGMA) by graft copolymerization of GMA onto electron beam (EB) irradiated polyethylenepolypropylene (PE/PP) fibrous sheets and subsequent amination with ethylenediamine (EDA), diethylenetriamine (DETA), or tetraethylenepentamine (TEPA). The physico-chemical properties of the adsorbents were evaluated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis. All the adsorbents displayed typic primary and secondary amine features combined with a decrease in both of crystallinity and surface area of PE/PP, and such a decrease was higher in adsorbents with longer aliphatic chain of the amine. Of all adsorbents, TEPA-containing fibres showed the highest CO2 adsorption capacity and thus was further investigated for CO2 capture from CO2/CH4 mixtures of different gas ratios under various pressures and temperatures. The selectivity of CO2 over CH4 and equilibrium isotherms, kinetics, and thermodynamics of the adsorption on the fibrous aminated adsorbent were all investigated. The Sips model was found to best fit the isotherm of CO2 adsorption suggesting the presence of a combination of monolayer and multilayer adsorptions. The adsorption kinetic data was found to best fit Elovich model reflecting chemisorption. The ΔG°, ΔS°, and ΔH° showed positive values suggesting that the adsorption of CO2 on the present fibrous adsorbent was non-spontaneous with an increase in randomness implying that the process was endothermic. Overall, it can be suggested that PE/PP-g-PGMA/TEPA adsorbent has a strong potential for separation of CO2 from NG.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  19. Synthesis of Pectin and Eggshell Biowaste-Mediated Nano-hydroxyapatite (nHAp), Their Physicochemical Characterizations, and Use as Antibacterial Material
    Thakur P, Arivarasan VK, Kumar G, Pant G, Kumar R, Pandit S, et al.
    Appl Biochem Biotechnol, 2024 Jan;196(1):491-505.
    PMID: 37145344 DOI: 10.1007/s12010-023-04550-6
    The current study reports the synthesis of sustainable nano-hydroxyapatite (nHAp) using a wet chemical precipitation approach. The materials used in the green synthesis of nHAp were obtained from environmental biowastes such as HAp from eggshells and pectin from banana peels. The physicochemical characterization of obtained nHAp was carried out using different techniques. For instance, X-ray diffractometer (XRD) and FTIR spectroscopy were used to study the crystallinity and synthesis of nHAp respectively. In addition, the morphology and elemental composition of nHAP were studied using FESEM equipped with EDX. HRTEM showed the internal structure of nHAP and calculated its grain size which was 64 nm. Furthermore, the prepared nHAp was explored for its antibacterial and antibiofilm activity which has received less attention previously. The obtained results showed the potential of pectin-bound nHAp as an antibacterial agent for various biomedical and healthcare applications.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
  20. Insight into microwave-assisted synthesis of the chitosan-MOF composite: Pb(II) adsorption
    Gul Zaman H, Baloo L, Kutty SR, Aziz K, Altaf M, Ashraf A, et al.
    Environ Sci Pollut Res Int, 2023 Jan;30(3):6216-6233.
    PMID: 35989404 DOI: 10.1007/s11356-022-22438-6
    Heavy metal contamination has increased over the globe, causing significant environmental issues owing to direct and indirect releases into water bodies. As a result, metal removal from water entities must be addressed soon. Various adsorbents such as MOFs and chitosan have demonstrated promising results in water treatment. The present study prepared a composite material (chitosan-UiO-66-glycidyl methacrylate MOF) by a microwave-assisted method. The structure and morphology of the chitosan-MOF composite were studied using FE-SEM, EDX, XRD, BET, FT-IR, and TGA techniques. In addition, the adsorption of Pb(II) from aqueous solution onto the chitosan-MOF composite was analyzed in a batch study concerning pH, contact time, initial metal ion concentration, and adsorbent dosage. The composite has a large surface area of 867 m2/g with a total pore volume of 0.51 cm3/g and thermal stability of up to 400 [Formula: see text]. Following an analysis of the adsorption isotherms, kinetics, and thermodynamics, the Langmuir model showed an excellent fit with the adsorption data (R2 = 0.99) and chi-squared (X2 = 3.609). The adsorption process was a spontaneous exothermic reaction and the pseudo-second-order rate equation fitted the kinetic profile well. Moreover, the composite is recyclable, retaining 83.45% of its removal effectiveness after 5 consecutive cycles, demonstrating it as a sustainable adsorbent for metal recovery. This study introduces a novel synthesized composite with enhanced recyclability and a higher potential for eliminating pollutants from industrial wastewater.
    Matched MeSH terms: Spectroscopy, Fourier Transform Infrared
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