Displaying publications 121 - 140 of 161 in total

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  1. High surface area mesoporous activated carbon-alginate beads for efficient removal of methylene blue
    Nasrullah A, Bhat AH, Naeem A, Isa MH, Danish M
    Int J Biol Macromol, 2018 Feb;107(Pt B):1792-1799.
    PMID: 29032214 DOI: 10.1016/j.ijbiomac.2017.10.045
    High surface area mesoporous activated carbon-alginate (AC-alginate) beads were successfully synthesized by entrapping activated carbon powder derived from Mangosteen fruit peel into calcium-alginate beads for methylene blue (MB) removal from aqueous solution. The structure and surface characteristics of AC-alginate beads were analyzed using Fourier transform infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and surface area analysis (SBET), while thermal properties were tested using thermogravimetric analysis (TGA). The effect of AC-alginate dose, pH of solution, contact time, initial concentration of MB solution and temperature on MB removal was elucidated. The results showed that the maximum adsorption capacity of 230mg/g was achieved for 100mg/L of MB solution at pH 9.5 and temperature 25°C. Furthermore, the adsorption of MB on AC-alginate beads followed well pseudo-second order equation and equilibrium adsorption data were better fitted by the Freundlich isotherm model. The findings reveal the feasibility of AC-alginate beads composite to be used as a potential and low cost adsorbent for removal of cationic dyes.
    Matched MeSH terms: Thermogravimetry
  2. Fulltext Mercerized mesoporous date pit activated carbon-A novel adsorbent to sequester potentially toxic divalent heavy metals from water
    Aldawsari A, Khan MA, Hameed BH, Alqadami AA, Siddiqui MR, Alothman ZA, et al.
    PLoS One, 2017;12(9):e0184493.
    PMID: 28910368 DOI: 10.1371/journal.pone.0184493
    A substantive approach converting waste date pits to mercerized mesoporous date pit activated carbon (DPAC) and utilizing it in the removal of Cd(II), Cu(II), Pb(II), and Zn(II) was reported. In general, rapid heavy metals adsorption kinetics for Co range: 25-100 mg/L was observed, accomplishing 77-97% adsorption within 15 min, finally, attaining equilibrium in 360 min. Linear and non-linear isotherm studies revealed Langmuir model applicability for Cd(II) and Pb(II) adsorption, while Freundlich model was fitted to Zn(II) and Cu(II) adsorption. Maximum monolayer adsorption capacities (qm) for Cd(II), Pb(II), Cu(II), and Zn(II) obtained by non-linear isotherm model at 298 K were 212.1, 133.5, 194.4, and 111 mg/g, respectively. Kinetics modeling parameters showed the applicability of pseudo-second-order model. The activation energy (Ea) magnitude revealed physical nature of adsorption. Maximum elution of Cu(II) (81.6%), Zn(II) (70.1%), Pb(II) (96%), and Cd(II) (78.2%) were observed with 0.1 M HCl. Thermogravimetric analysis of DPAC showed a total weight loss (in two-stages) of 28.3%. Infra-red spectral analysis showed the presence of carboxyl and hydroxyl groups over DPAC surface. The peaks at 820, 825, 845 and 885 cm-1 attributed to Zn-O, Pb-O, Cd-O, and Cu-O appeared on heavy metals saturated DPAC, confirmed their binding on DPAC during the adsorption.
    Matched MeSH terms: Thermogravimetry
  3. Fulltext Development and blood compatibility assessment of electrospun polyvinyl alcohol blended with metallocene polyethylene and plectranthus amboinicus (PVA/mPE/PA) for bone tissue engineering
    Qi J, Zhang H, Wang Y, Mani MP, Jaganathan SK
    Int J Nanomedicine, 2018;13:2777-2788.
    PMID: 29785105 DOI: 10.2147/IJN.S151242
    Introduction: Currently, the design of extracellular matrix (ECM) with nanoscale properties in bone tissue engineering is challenging. For bone tissue engineering, the ECM must have certain properties such as being nontoxic, highly porous, and should not cause foreign body reactions.

    Materials and methods: In this study, the hybrid scaffold based on polyvinyl alcohol (PVA) blended with metallocene polyethylene (mPE) and plectranthus amboinicus (PA) was fabricated for bone tissue engineering via electrospinning. The fabricated hybrid nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform and infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement, and atomic force microscopy (AFM). Furthermore, activated partial thromboplastin time (APTT), prothrombin time (PT), and hemolytic assays were used to investigate the blood compatibility of the prepared hybrid nanocomposites.

    Results: The prepared hybrid nanocomposites showed reduced fiber diameter (238±45 nm) and also increased porosity (87%) with decreased pore diameter (340±86 nm) compared with pure PVA. The interactions between PVA, mPE, and PA were identified by the formation of the additional peaks as revealed in FTIR. Furthermore, the prepared hybrid nanocomposites showed a decreased contact angle of 51°±1.32° indicating a hydrophilic nature and exhibited lower thermal stability compared to pristine PVA. Moreover, the mechanical results revealed that the electrospun scaffold showed an improved tensile strength of 3.55±0.29 MPa compared with the pristine PVA (1.8±0.52 MPa). The prepared hybrid nanocomposites showed delayed blood clotting as noted in APTT and PT assays indicating better blood compatibility. Moreover, the hemolysis assay revealed that the hybrid nanocomposites exhibited a low hemolytic index of 0.6% compared with pure PVA, which was 1.6% suggesting the safety of the developed nanocomposite to red blood cells (RBCs).

    Conclusion: The prepared nanocomposites exhibited better physico-chemical properties, sufficient porosity, mechanical strength, and blood compatibility, which favors it as a valuable candidate in bone tissue engineering for repairing the bone defects.

    Matched MeSH terms: Thermogravimetry
  4. Purification of lysozyme from chicken egg white using nanofiber membrane immobilized with Reactive Orange 4 dye
    Ng IS, Song CP, Ooi CW, Tey BT, Lee YH, Chang YK
    Int J Biol Macromol, 2019 Aug 01;134:458-468.
    PMID: 31078593 DOI: 10.1016/j.ijbiomac.2019.05.054
    Nanofiber membrane chromatography integrates liquid membrane chromatography and nanofiber filtration into a single-step purification process. Nanofiber membrane can be functionalised with affinity ligands for promoting binding specificity of membrane. Dye molecules are a good affinity ligand for nanofiber membrane due to their low cost and high binding affinity. In this study, a dye-affinity nanofiber membrane (P-Chitosan-Dye membrane) was prepared by using polyacrylonitrile nanofiber membrane modified with chitosan molecules and immobilized with dye molecules. Reactive Orange 4, commercially known as Procion Orange MX2R, was found to be the best dye ligand for membrane chromatography. The binding capacity of P-Chitosan-Dye membrane for lysozyme was investigated under different operating conditions in batch mode. Furthermore, desorption of lysozyme using the P-Chitosan-Dye membrane was evaluated systematically. The recovery percentage of lysozyme was found to be ~100%. The optimal conditions obtained from batch-mode study were adopted to develop a purification process to separate lysozyme from chicken egg white. The process was operated continuously using the membrane chromatography and the characteristic of the breakthrough curve was evaluated. At a lower flow rate (i.e., 0.1 mL/min), the total recovery of lysozyme and purification factor of lysozyme were 98.59% and 56.89 folds, respectively.
    Matched MeSH terms: Thermogravimetry
  5. Potential of using multiscale corn husk fiber as reinforcing filler in cornstarch-based biocomposites
    Ibrahim MIJ, Sapuan SM, Zainudin ES, Zuhri MYM
    Int J Biol Macromol, 2019 Oct 15;139:596-604.
    PMID: 31381916 DOI: 10.1016/j.ijbiomac.2019.08.015
    In this study, biodegradable composite films were prepared by using thermoplastic cornstarch matrix and corn husk fiber as a reinforcing filler. The composite films were manufactured via a casting technique using different concentrations of husk fiber (0-8%), and fructose as a plasticizer at a fixed amount of 25% for starch weight. The Physical, thermal, morphological, and tensile characteristics of composite films were investigated. The findings indicated that the incorporation of husk fiber, in general, enhanced the performance of the composite films. There was a noticeable reduction in the density and moisture content of the films, and soil burial assessment showed less resistance to biodegradation. The morphological images presented a consistent structure and excellent compatibility between matrix and reinforcement, which reflected on the improved tensile strength and young modulus as well as the crystallinity index. The thermal stability of composite films has also been enhanced, as evidenced by the increased onset decomposition temperature of the reinforced films compared to neat film. Fourier transform infrared analysis revealed increasing in intermolecular hydrogen bonding following fiber loading. The composite materials prepared using corn husk residues as reinforcement responded to community demand for agricultural and polymeric waste disposal and added more value to waste management.
    Matched MeSH terms: Thermogravimetry
  6. Pre-dispersed organo-montmorillonite (organo-MMT) nanofiller: Morphology, cytocompatibility and impact on flexibility, toughness and biostability of biomedical ethyl vinyl acetate (EVA) copolymer
    Osman AF, M Fitri TF, Rakibuddin M, Hashim F, Tuan Johari SAT, Ananthakrishnan R, et al.
    Mater Sci Eng C Mater Biol Appl, 2017 May 01;74:194-206.
    PMID: 28254285 DOI: 10.1016/j.msec.2016.11.137
    Polymer-clay based nanocomposites are among the attractive materials to be applied for various applications, including biomedical. The incorporation of the nano sized clay (nanoclay) into polymer matrices can result in their remarkable improvement in mechanical, thermal and barrier properties as long as the nanofillers are well exfoliated and dispersed throughout the matrix. In this work, exfoliation strategy through pre-dispersing process of the organically modified montmorillonite (organo-MMT) nanofiller was done to obtain ethyl vinyl acetate (EVA) nanocomposite with improved flexibility, toughness, thermal stability and biostability. Our results indicated that the degree of organo-MMT exfoliation affects its cytotoxicity level and the properties of the resulting EVA nanocomposite. The pre-dispersed organo-MMT by ultrasonication in water possesses higher degree of exfoliation as compared to its origin condition and significantly performed reduced cytotoxicity level. Beneficially, this nanofiller also enhanced the EVA flexibility, thermal stability and biostability upon the in vitro exposure. We postulated that these were due to plasticizing effect and enhanced EVA-nanofiller interactions contributing to more stable chemical bonds in the main copolymer chains. Improvement in copolymer flexibility is beneficial for close contact with human soft tissue, while enhancement in toughness and biostability is crucial to extend its life expectancy as insulation material for implantable device.
    Matched MeSH terms: Thermogravimetry
  7. An injectable poly(caprolactone trifumarate-gelatin microparticles) (PCLTF-GMPs) scaffold for irregular bone defects: Physical and mechanical characteristics
    Al-Namnam NM, Kutty MG, Chai WL, Ha KO, Kim KH, Siar CH, et al.
    Mater Sci Eng C Mater Biol Appl, 2017 Mar 01;72:332-340.
    PMID: 28024594 DOI: 10.1016/j.msec.2016.11.086
    Recently, a modified form of a three-dimension (3D) porous poly(caprolactone-trifumarate) (PCLTF) scaffold has been produced using a fabrication technique that involves gelatin microparticles porogen leaching. This poly(caprolactone trifumarate-gelatin microparticles) (PCLTF-GMPs) scaffold has been shown to be biocompatible, more flowable clinically, and has a shorter degradation time as compared to its existing predecessors. In this report, a detailed characterization of this new scaffold was performed by testing its cytocompatibility, analyzing the surface topography, and understanding its thermal, physical and mechanical properties. The result showed that the PCLTF-GMPs has no critical cytotoxic effect. To confirm improvement, the surface properties were compared against the older version of PCLTF fabricated using salt porogen leaching. This PCLTF-GMPs scaffold showed no significant difference (unpaired t-test; p>0.05) in mechanical properties before and after gelatin leaching. However, it is mechanically weaker when compared to its predecessors. It has a high biodegradability rate of 16weeks. The pore size produced ranges from 40 to 300μm, and the RMS roughness is 613.7±236.9nm. These characteristics are condusive for osteoblast in-growth, as observed by the extension of filopodia across the macropores. Overall, this newly produced material has good thermal, physical and mechanical properties that complements its biocompatibility and ease of use.
    Matched MeSH terms: Thermogravimetry
  8. Fulltext Conventional study on novel dicationic ionic liquid inclusion with β-cyclodextrin
    Mohamad S, Surikumaran H, Raoov M, Marimuthu T, Chandrasekaram K, Subramaniam P
    Int J Mol Sci, 2011;12(9):6329-45.
    PMID: 22016662 DOI: 10.3390/ijms12096329
    This study focuses on the synthesis and characterization of the inclusion complex of β-Cyclodextrin (β-CD) with dicationic ionic liquid, 3,3'-(1,4-Phenylenebis [methylene]) bis(1-methyl-1H-imidazol-3-ium) di(bromide) (PhenmimBr). The inclusion complex was prepared at room temperature utilizing conventional kneading technique. Proton ((1)H) NMR and 2D ((1)H-(1)H) COSY NMR were the primary characterization tools employed to verify the formation of the inclusion complex. COSY spectra showed strong correlations between protons of imidazolium and protons of β-CD which indicates that the imidazolium ring of PhenmimBr has entered the cavity of β-CD. UV absorption indicated that β-CD reacts with PhenmimBr to form a 2:1 β-CD-PhenmimBr complex with an apparent formation constant of 2.61 × 10(5) mol&(-2) L(2). Other characterization studies such as UV, FT-IR, XRD, TGA, DSC and SEM studies were also used to further support the formation of the β-CD-PhenmimBr inclusion complex.
    Matched MeSH terms: Thermogravimetry
  9. Fulltext Synthesis of nanocrystalline SnO(x) (x = 1-2) thin film using a chemical bath deposition method with improved deposition time, temperature and pH
    Ebrahimiasl S, Yunus WM, Kassim A, Zainal Z
    Sensors (Basel), 2011;11(10):9207-16.
    PMID: 22163690 DOI: 10.3390/s111009207
    Nanocrystalline SnO(x) (x = 1-2) thin films were prepared on glass substrates by a simple chemical bath deposition method. Triethanolamine was used as complexing agent to decrease time and temperature of deposition and shift the pH of the solution to the noncorrosive region. The films were characterized for composition, surface morphology, structure and optical properties. X-ray diffraction analysis confirms that SnO(x) thin films consist of a polycrystalline structure with an average grain size of 36 nm. Atomic force microscopy studies show a uniform grain distribution without pinholes. The elemental composition was evaluated by energy dispersive X-ray spectroscopy. The average O/Sn atomic percentage ratio is 1.72. Band gap energy and optical transition were determined from optical absorbance data. The film was found to exhibit direct and indirect transitions in the visible spectrum with band gap values of about 3.9 and 3.7 eV, respectively. The optical transmittance in the visible region is 82%. The SnO(x) nanocrystals exhibit an ultraviolet emission band centered at 392 nm in the vicinity of the band edge, which is attributed to the well-known exciton transition in SnO(x). Photosensitivity was detected in the positive region under illumination with white light.
    Matched MeSH terms: Thermogravimetry
  10. Fulltext Degradability enhancement of poly(lactic acid) by stearate-Zn(3)Al LDH nanolayers
    Eili M, Shameli K, Ibrahim NA, Wan Yunus WMZ
    Int J Mol Sci, 2012;13(7):7938-7951.
    PMID: 22942682 DOI: 10.3390/ijms13077938
    Recent environmental problems and societal concerns associated with the disposal of petroleum based plastics throughout the world have triggered renewed efforts to develop new biodegradable products compatible with our environment. This article describes the preparation, characterization and biodegradation study of poly(lactic acid)/layered double hydroxide (PLA/LDH) nanocomposites from PLA and stearate-Zn(3)Al LDH. A solution casting method was used to prepare PLA/stearate-Zn(3)Al LDH nanocomposites. The anionic clay Zn(3)Al LDH was firstly prepared by co-precipitation method from a nitrate salt solution at pH 7.0 and then modified by stearate anions through an ion exchange reaction. This modification increased the basal spacing of the synthetic clay from 8.83 Å to 40.10 Å. The morphology and properties of the prepared PLA/stearate-Zn(3)Al LDH nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), tensile tests as well as biodegradation studies. From the XRD analysis and TEM observation, the stearate-Zn(3)Al LDH lost its ordered stacking-structure and was greatly exfoliated in the PLA matrix. Tensile test results of PLA/stearate-Zn(3)Al LDH nanocomposites showed that the presence of around 1.0-3.0 wt % of the stearate-Zn(3)Al LDH in the PLA drastically improved its elongation at break. The biodegradation studies demonstrated a significant biodegradation rate improvement of PLA in the presence of stearate-Zn(3)Al LDH nanolayers. This effect can be caused by the catalytic role of the stearate groups in the biodegradation mechanism leading to much faster disintegration of nanocomposites than pure PLA.
    Matched MeSH terms: Thermogravimetry
  11. Effects of aeration rate on degradation process of oil palm empty fruit bunch with kinetic-dynamic modeling
    Talib AT, Mokhtar MN, Baharuddin AS, Sulaiman A
    Bioresour Technol, 2014 Oct;169:428-38.
    PMID: 25079208 DOI: 10.1016/j.biortech.2014.07.033
    The effect of different aeration rates on the organic matter (OM) degradation during the active phase of oil palm empty fruit bunch (EFB)-rabbit manure co-composting process under constant forced-aeration system has been studied. Four different aeration rates, 0.13 L min(-1) kg(DM)(-1),0.26 L min(-1) kg(DM)(-1),0.49 L min(-1) kg(DM)(-1) and 0.74 L min(-1) kg(DM)(-1) were applied. 0.26 L min(-1) kg(DM)(-1) provided enough oxygen level (10%) for the rest of composting period, showing 40.5% of OM reduction that is better than other aeration rates. A dynamic mathematical model describing OM degradation, based on the ratio between OM content and initial OM content with correction functions of moisture content, free air space, oxygen and temperature has been proposed.
    Matched MeSH terms: Thermogravimetry
  12. Antimicrobial and in vitro wound healing properties of novel clay based bionanocomposite films
    Mishra RK, Ramasamy K, Lim SM, Ismail MF, Majeed AB
    J Mater Sci Mater Med, 2014 Aug;25(8):1925-39.
    PMID: 24831081 DOI: 10.1007/s10856-014-5228-y
    The present study investigates the development of methyl cellulose (MC)-sodium alginate (SA)-montmorillonite (MMT) clay based bionanocomposite films with interesting wound healing properties. The differential scanning calorimetry analysis of the composite films revealed presence of single glass transition temperature (Tg) confirming the miscible nature of the ternary blended films. The increase in MMT ratio in the composite films reduced the mobility of biopolymer chains (MC/SA) which increased the Tg of the film. Thermogravimetric analysis showed that dispersion of clay (MMT) at nano level significantly delayed the weight loss that correlated with higher thermal stability of the composite films. It was observed that the developed films were able to exhibit antimicrobial activity against four typical pathogenic bacteria found in the presence of wound. The developed films were able to significantly inhibit (10 mg/ml) the growth of Enterococcus faecium and Pseudomonas aeruginosa. In vitro scratch assay indicated potential wound closure activities of MC-2-4 bionanocomposite films at their respective highest subtoxic doses. In conclusion, these ternary bionanocomposite films were found to be promising systems for wound healing applications.
    Matched MeSH terms: Thermogravimetry
  13. Fulltext The use of Hibiscus esculentus (Okra) gum in sustaining the release of propranolol hydrochloride in a solid oral dosage form
    Zaharuddin ND, Noordin MI, Kadivar A
    Biomed Res Int, 2014;2014:735891.
    PMID: 24678512 DOI: 10.1155/2014/735891
    The effectiveness of Okra gum in sustaining the release of propranolol hydrochloride in a tablet was studied. Okra gum was extracted from the pods of Hibiscus esculentus using acetone as a drying agent. Dried Okra gum was made into powder form and its physical and chemical characteristics such as solubility, pH, moisture content, viscosity, morphology study using SEM, infrared study using FTIR, crystallinity study using XRD, and thermal study using DSC and TGA were carried out. The powder was used in the preparation of tablet using granulation and compression methods. Propranolol hydrochloride was used as a model drug and the activity of Okra gum as a binder was compared by preparing tablets using a synthetic and a semisynthetic binder which are hydroxylmethylpropyl cellulose (HPMC) and sodium alginate, respectively. Evaluation of drug release kinetics that was attained from dissolution studies showed that Okra gum retarded the release up to 24 hours and exhibited the longest release as compared to HPMC and sodium alginate. The tensile and crushing strength of tablets was also evaluated by conducting hardness and friability tests. Okra gum was observed to produce tablets with the highest hardness value and lowest friability. Hence, Okra gum was testified as an effective adjuvant to produce favourable sustained release tablets with strong tensile and crushing strength.
    Matched MeSH terms: Thermogravimetry
  14. Synthesis and characterization of magnesium doped biphasic calcium phosphate
    Toibah AR, Sopyan I, Mel M
    Med J Malaysia, 2008 Jul;63 Suppl A:83-4.
    PMID: 19024995
    The incorporation of magnesium ions into the calcium phosphate structure is of great interest for the development of artificial bone implants. This paper investigates the preparation of magnesium-doped biphasic calcium phosphate (Mg-BCP) via sol gel method at various concentrations of added Mg. The effect of calcinations temperature (ranging from 500 degrees C to 900 degrees C) and concentrations of Mg incorporated into BCP has been studied by the aid of XRD, TGA and infrared spectroscopy (IR) in transmittance mode analysis. The study indicated that the powder was pure BCP and Mg-BCP with 100% purity and high crystallinity. The results also indicated that beta-tricalcium phosphate (beta-TCP) phase can be observed when the powder was calcined at 800 degrees C and above.
    Matched MeSH terms: Thermogravimetry
  15. Fulltext Potential biosorbent derived from Calligonum polygonoides for removal of methylene blue dye from aqueous solution
    Nasrullah A, Khan H, Khan AS, Man Z, Muhammad N, Khan MI, et al.
    ScientificWorldJournal, 2015;2015:562693.
    PMID: 25705714 DOI: 10.1155/2015/562693
    The ash of C. polygonoides (locally called balanza) was collected from Lakki Marwat, Khyber Pakhtunkhwa, Pakistan, and was utilized as biosorbent for methylene blue (MB) removal from aqueous solution. The ash was used as biosorbent without any physical or chemical treatment. The biosorbent was characterized by using various techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The particle size and surface area were measured using particle size analyzer and Brunauer-Emmett-Teller equation (BET), respectively. The SEM and BET results expressed that the adsorbent has porous nature. Effects of various conditions such as initial concentration of methylene blue (MB), initial pH, contact time, dosage of biosorbent, and stirring rate were also investigated for the adsorption process. The rate of the adsorption of MB on biomass sample was fast, and equilibrium has been achieved within 1 hour. The kinetics of MB adsorption on biosorbent was studied by pseudo-first- and pseudo-second-order kinetic models and the pseudo-second-order has better mathematical fit with correlation coefficient value (R (2)) of 0.999. The study revealed that C. polygonoides ash proved to be an effective, alternative, inexpensive, and environmentally benign biosorbent for MB removal from aqueous solution.
    Matched MeSH terms: Thermogravimetry
  16. Fulltext Synthesis and characterization of β-cyclodextrin functionalized ionic liquid polymer as a macroporous material for the removal of phenols and As(V)
    Raoov M, Mohamad S, Abas MR
    Int J Mol Sci, 2014;15(1):100-19.
    PMID: 24366065 DOI: 10.3390/ijms15010100
    β-Cyclodextrin-ionic liquid polymer (CD-ILP) was first synthesized by functionalized β-cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (βCD-BIMOTs) and was further polymerized using a toluene diisocyanate (TDI) linker to form insoluble CD-ILP (βCD-BIMOTs-TDI). The βCD-BIMOTs-TDI polymer was characterized using various tools and the results obtained were compared with those derived from the native β-cyclodextrin polymer (βCD-TDI). The SEM result shows that the presence of ionic liquid (IL) increases the pore size, while the thermo gravimetric analysis (TGA) result shows that the presence of IL increases the stability of the polymer. Meanwhile, Brunauer-Emmett-Teller (BET) results show that βCD-BIMOTs-TDI polymer has 1.254 m(2)/g surface areas and the Barret-Joyner-Halenda (BJH) pore size distribution result reveals that the polymer exhibits macropores with a pore size of 77.66 nm. Preliminary sorption experiments were carried out and the βCD-BIMOTs-TDI polymer shows enhanced sorption capacity and high removal towards phenols and As(V).
    Matched MeSH terms: Thermogravimetry
  17. Fulltext Sustained release of prindopril erbumine from its chitosan-coated magnetic nanoparticles for biomedical applications
    Dorniani D, Hussein MZ, Kura AU, Fakurazi S, Shaari AH, Ahmad Z
    Int J Mol Sci, 2013;14(12):23639-53.
    PMID: 24300098 DOI: 10.3390/ijms141223639
    The preparation of magnetic nanoparticles coated with chitosan-prindopril erbumine was accomplished and confirmed by X-ray diffraction, TEM, magnetic measurements, thermal analysis and infrared spectroscopic studies. X-ray diffraction and TEM results demonstrated that the magnetic nanoparticles were pure iron oxide phase, having a spherical shape with a mean diameter of 6 nm, compared to 15 nm after coating with chitosan-prindopril erbumine (FCPE). Fourier transform infrared spectroscopy study shows that the coating of iron oxide nanoparticles takes place due to the presence of some bands that were emerging after the coating process, which belong to the prindopril erbumine (PE). The thermal stability of the PE in an FCPE nanocomposite was remarkably enhanced. The release study showed that around 89% of PE could be released within about 93 hours by a phosphate buffer solution at pH 7.4, which was found to be of sustained manner governed by first order kinetic. Compared to the control (untreated), cell viability study in 3T3 cells at 72 h post exposure to both the nanoparticles and the pure drug was found to be sustained above 80% using different doses.
    Matched MeSH terms: Thermogravimetry
  18. Fulltext Synthesis, characterization, X-ray structure and biological activities of C-5-bromo-2-hydroxyphenylcalix[4]-2-methyl resorcinarene
    Abosadiya HM, Hasbullah SA, Mackeen MM, Low SC, Ibrahim N, Koketsu M, et al.
    Molecules, 2013;18(11):13369-84.
    PMID: 24172244 DOI: 10.3390/molecules181113369
    C-5-bromo-2-hydroxyphenylcalix[4]-2-methylresorcinarene (I) was synthesized by cyclocondensation of 5-bromo-2-hydroxybenzaldehyde and 2-methylresorcinol in the presence of concentrated HCl. Compound I was characterized by infrared and nuclear magnetic resonance spectroscopic data. X-ray analysis showed that this compound crystallized in a triclinic system with space group of Pī, a = 15.9592(16)Å, b = 16.9417(17)Å, c = 17.0974(17)Å, α = 68.656(3)°, β = 85.689(3)°, γ = 81.631(3)°, Z = 2 and V = 4258.6(7)Å3. The molecule adopts a chair (C2h) conformation. The thermal properties and antioxidant activity were also investigated. It was strongly antiviral against HSV-1 and weakly antibacterial against Gram-positive bacteria. Cytotoxicity testing on Vero cells showed that it is non-toxic, with a CC50 of more than 0.4 mg/mL.
    Matched MeSH terms: Thermogravimetry
  19. CO2 gasification reactivity of biomass char: catalytic influence of alkali, alkaline earth and transition metal salts
    Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M
    Bioresour Technol, 2013 Sep;144:288-95.
    PMID: 23880130 DOI: 10.1016/j.biortech.2013.06.059
    This study investigates the influence of alkali (Na, K), alkaline earth (Ca, Mg) and transition (Fe) metal nitrates on CO2 gasification reactivity of pistachio nut shell (PNS) char. The preliminary gasification experiments were performed in thermogravimetric analyzer (TGA) and the results showed considerable improvement in carbon conversion; Na-char>Ca-char>Fe-char>K-char>Mg-char>raw char. Based on TGA studies, NaNO3 (with loadings of 3-7 wt%) was selected as the superior catalyst for further gasification studies in bench-scale reactor; the highest reactivity was devoted to 5 wt% Na loaded char. The data acquired for gasification rate of catalyzed char were fitted with several kinetic models, among which, random pore model was adopted as the best model. Based on obtained gasification rate constant and using the Arrhenius plot, activation energy of 5 wt% Na loaded char was calculated as 151.46 kJ/mol which was 53 kJ/mol lower than that of un-catalyzed char.
    Matched MeSH terms: Thermogravimetry
  20. Stimuli-responsive bacterial cellulose-g-poly(acrylic acid-co-acrylamide) hydrogels for oral controlled release drug delivery
    Mohd Amin MC, Ahmad N, Pandey M, Jue Xin C
    Drug Dev Ind Pharm, 2014 Oct;40(10):1340-9.
    PMID: 23875787 DOI: 10.3109/03639045.2013.819882
    This study evaluated the potential of stimuli-responsive bacterial cellulose-g-poly(acrylic acid-co-acrylamide) hydrogels as oral controlled-release drug delivery carriers. Hydrogels were synthesized by graft copolymerization of the monomers onto bacterial cellulose (BC) fibers by using a microwave irradiation technique. The hydrogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). FT-IR spectroscopy confirmed the grafting. XRD showed that the crystallinity of BC was reduced by grafting, whereas an increase in the thermal stability profile was observed in TGA. SEM showed that the hydrogels exhibited a highly porous morphology, which is suitable for drug loading. The hydrogels demonstrated a pH-responsive swelling behavior, with decreased swelling in acidic media, which increased with increase in pH of the media, reaching maximum swelling at pH 7. The release profile of the hydrogels was investigated in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The hydrogels showed lesser release in SGF than in SIF, suggesting that hydrogels may be suitable drug carriers for oral controlled release of drug delivery in the lower gastrointestinal tract.
    Matched MeSH terms: Thermogravimetry
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