scholarly journals Structural effect of monomer type on properties of copolyimides and copolyimide-silica hybrid materials

2015 ◽  
Vol 80 (8) ◽  
pp. 1061-1071 ◽  
Author(s):  
Canan Kizilkaya ◽  
Merve Bicen ◽  
Sevim Karatas ◽  
Atilla Gungor
Keyword(s):  
Hybrid Materials ◽  
Phosphine Oxide ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Decomposition Temperature ◽  
Structural Effect ◽  
Sem Analysis ◽  
Morphological Properties ◽  
Resonance Spectroscopy ◽  
Phenylphosphine Oxide

In this work, the effect of two different diamine monomers, containing phosphine oxide, on thermal, mechanical and morphological properties of copolyimides and their hybrid materials was investigated. Gas separation properties of the synthesized copolyimides were also analysed. Two different diamine monomers with phosphine oxide were bis(3-aminophenyl) phenylphosphine oxide (BAPPO) and bis(3-aminophenoxy-4-phenyl) phenylphosphine oxide (m-BAPPO). In the synthesis of copolyimides 3,3?-diamino-diphenyl sulfone (DDS) was also used as the diamine, as well as 2,2?-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA). Copolyimide films were prepared by thermal imidization. Hybrid materials containing 5 % SiO2 were synthesised further by sol-gel technique. The Fourier-transform infrared spectroscopy (FTIR), Nuclear magnetic resonance spectroscopy (NMR) confirmed the expected structure. Dynamic mechanical analysis (DMA) demonstrated that m-BAPPO based copolyimides had lower glass transition temperatures (Tg) than BAPPO based copolyimides. m-BAPPO containing copolyimide without silica shifted the thermal decomposition temperature to a higher value. The moduli and strength values of BAPPO diamine containing copolyimide and its hybrid were higher than those of m-BAPPO containing materials. The contact angle measurements showed the hydrophobicity. Scanning electron microscope (SEM) analysis exhibited the silica particles dispersion in the copolyimides. These copolyimides may be used in the coating industry. The CO2 permeability and the permselectivity were the highest among the other values in this study, when m-BAPPO containing copolyimide in the absence of silica was used. The gas permeabilities obtained from this work were in this decreasing order: PCO2 > PO2 > PN2.

Antibacterial Activity of Nickel -Doped ZnO\MWCNTs hybrid Prepared by Sol-Gel technique

2021 ◽  
Author(s):  
Selma M.H. AL-Jawad ◽  
Zahraa S. Shakir ◽  
Duha S. Ahmed
Keyword(s):  
Antibacterial Activity ◽  
Sol Gel ◽  
Inhibition Zone ◽  
Sem Analysis ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Doped Zno

ZnO/MWCNTs hybrid and doped with different concentration of Nickel element prepared by using Sol-gel been technique reported. All samples were prepared and characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectroscopy have been identified the structural, optical and morphological properties. X-ray diffraction showed the polycrystalline nature with hexagonal wutzite structure of hybrid and doped with Nickel. The crystalline size of the hybrid nanostructure was increasing from 23.73 nm to 34.59 nm. Besides, the UV-Vis spectroscopy showed a significant decrease in the band gap values from 2.97 eV to 2.01 eV. Whereas the FE-SEM analysis confirm the formation spherical shapes of ZnO NPs deposited on cylindrical tubes representing the MWCNTs. The antibacterial activity reveals that the inhibition zone of Ni doped-ZnO/MWCNTs hybrid was 28.5 mm, 26.5 mm toward E. coli and S. aureus bacteria, respectively.

Morphology and Properties of Polyoxymethylene/Polypropylene/Microcrystalline Cellulose Composites

2017 ◽  
Vol 751 ◽  
pp. 264-269
Author(s):  
Nipawan Yasumlee ◽  
Sirirat Wacharawichanant
Keyword(s):  
Thermal Stability ◽  
Microcrystalline Cellulose ◽  
Decomposition Temperature ◽  
Sem Analysis ◽  
Morphological Properties ◽  
Melt Mixing ◽  
Cellulose Composites ◽  
The Difference ◽  
Pp Blends ◽  
Internal Mixer

The effects of microcrystalline cellulose (MCC) on mechanical, thermal and morphological properties of polyoxymethylene (POM)/polypropylene (PP) blends at different compositions were investigated. The blends and composites were prepared by melt mixing using an internal mixer at 200°C. Scanning electron microscopy (SEM) analysis revealed phase separation between POM and PP phases due to the difference in polarity of POM and PP. When adding the MCC in the blends the morphology slightly changed due to the weak interaction between MCC and polymer phases. Incorporation of MCC at 5 phr could improve Young’s modulus of POM/PP blends. The storage modulus of the blends was improved after adding MCC 5 phr due to reinforcing effect of the MCC. The thermal properties found that the addition of MCC had no effect on the melting temperature of the blends. The blends exhibited higher decomposition temperature than pure POM. The blends showed the decomposition temperatures increased when increasing amount of PP content, which were higher than pure POM. Therefore, it may be inferred that the addition of PP could enhance the thermal stability of the POM/PP blends, but the addition of MCC did not improve the thermal stability.

scholarly journals Hybrid Materials Based on Silica Matrices Impregnated with Pt-Porphyrin or PtNPs Destined for CO2 Gas Detection or for Wastewaters Color Removal

2020 ◽  
Vol 21 (12) ◽  
pp. 4262 ◽  
Author(s):  
Diana Anghel ◽  
Anca Lascu ◽  
Camelia Epuran ◽  
Ion Fratilescu ◽  
Catalin Ianasi ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Dye Adsorption ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Morphological Properties ◽  
Order Kinetic ◽  
Co2 Gas ◽  
Bet Analysis ◽  
Silica Matrices

Multifunctional hybrid materials with applications in gas sensing or dye removal from wastewaters were obtained by incorporation into silica matrices of either Pt(II)-5,10,15,20-tetra-(4-allyloxy-phenyl)-porphyrin (PtTAOPP) or platinum nanoparticles (PtNPs) alone or accompanied by 5,10,15,20-tetra-(4-allyloxy-phenyl)-porphyrin (TAOPP). The tetraethylorthosilicate (TEOS)-based silica matrices were obtained by using the sol-gel method performed in two step acid-base catalysis. Optical, structural and morphological properties of the hybrid materials were determined and compared by UV-vis, fluorescence and FT-IR spectroscopy techniques, by atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) and by Brunauer–Emmett–Teller (BET) analysis. PtTAOPP-silica hybrid was the most efficient material both for CO2 adsorption (0.025 mol/g) and for methylene blue adsorption (7.26 mg/g) from wastewaters. These results were expected due to both the ink-bottle mesopores having large necks that exist in this hybrid material and to the presence of the porphyrin moiety that facilitates chemical interactions with either CO2 gas or the dye molecule. Kinetic studies concerning the mechanism of dye adsorption demonstrated a second order kinetic model, thus it might be attributed to both physical and chemical processes.

scholarly journals Titania-Based Hybrid Materials with ZnO, ZrO2 and MoS2: A Review

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2295 ◽  
Author(s):  
Adam Kubiak ◽  
Katarzyna Siwińska-Ciesielczyk ◽  
Teofil Jesionowski
Keyword(s):  
Hybrid Systems ◽  
Hybrid Materials ◽  
Binary Systems ◽  
Sol Gel ◽  
Morphological Properties ◽  
Oxide Systems ◽  
Practical Applications ◽  
Current State ◽  
Physico Chemical ◽  
Electrospinning Method

Titania has properties that enable it to be used in a variety of applications, including self-cleaning surfaces, air and water purification systems, hydrogen evolution, and photoelectrochemical conversion. In order to improve the properties of titanium dioxide, modifications are made to obtain oxide/hybrid systems that are intended to have the properties of both components. In particular, zinc oxide, zirconia and molybdenum disulfide have been proposed as the second component of binary systems due to their antibacterial, electrochemical and photocatalytic properties. This paper presents a review of the current state of knowledge on the synthesis and practical utility of TiO2-ZnO and TiO2-ZrO2 oxide systems and TiO2-MoS2 hybrid materials. The first part focuses on the hydrothermal method; then a review is made of the literature on the synthesis of the aforementioned materials using the sol-gel method. In the last section, the literature on the electrospinning method of synthesis is reviewed. The most significant physico-chemical, structural and dispersive-morphological properties of binary hybrid systems based on TiO2 are described. A key aim of this review is to indicate the properties of TiO2-ZnO, TiO2-ZrO2 and TiO2-MoS2 hybrid systems that have the greatest importance for practical applications. The variety of utilities of titania-based hybrid materials is emphasized.

scholarly journals Comparative Study of ZnO Thin Films Doped with Transition Metals (Cu and Co) for Methylene Blue Photodegradation under Visible Irradiation

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 528 ◽  
Author(s):  
William Vallejo ◽  
Alvaro Cantillo ◽  
Briggitte Salazar ◽  
Carlos Diaz-Uribe ◽  
Wilkendry Ramos ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Sol Gel ◽  
Physicochemical Characterization ◽  
Thin Film Deposition ◽  
Sem Analysis ◽  
Film Deposition ◽  
Morphological Properties ◽  
Visible Irradiation ◽  
Doped Zno

We synthesized and characterized both Co-doped ZnO (ZnO:Co) and Cu-doped ZnO (ZnO:Cu) thin films. The catalysts’ synthesis was carried out by the sol–gel method while the doctor blade technique was used for thin film deposition. The physicochemical characterization of the catalysts was carried out by Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction, and diffuse reflectance measurements. The photocatalytic activity was studied under visible irradiation in aqueous solution, and kinetic parameters were determined by pseudo-first-order fitting. The Raman spectra results evinced the doping process and suggested the formation of heterojunctions for both dopants. The structural diffraction patterns indicated that the catalysts were polycrystalline and demonstrated the presence of a ZnO wurtzite crystalline phase. The SEM analysis showed that the morphological properties changed significantly, the micro-aggregates disappeared, and agglomeration was reduced after modification of ZnO. The ZnO optical bandgap (3.22 eV) reduced after the doping process, these being ZnO:Co (2.39 eV) and ZnO:Co (3.01 eV). Finally, the kinetic results of methylene blue photodegradation reached 62.6% for ZnO:Co thin films and 42.5% for ZnO:Cu thin films.

scholarly journals Synthesis, characterization and adsorption properties of nanostructured hybrid materials modified by boron and zirconium

2012 ◽  
Vol 10 (5) ◽  
pp. 1484-1494 ◽  
Author(s):  
Ralitsa Georgieva ◽  
Paunka Vassileva ◽  
Albena Detcheva ◽  
Dimitrinka Voykova ◽  
Tsvetelina Gerganova ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Ph Value ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Inorganic Materials ◽  
Resonance Spectroscopy ◽  
Kinetics Of Adsorption ◽  
Equilibrium Data ◽  
Adsorption Of Nitrogen

AbstractThe adsorption properties of two new nanostructured hybrid materials containing B2O3 and ZrO2 were studied. The new organic-inorganic materials were synthesized via a sol-gel method. As a modifying agent, a quantity of 10 wt.% Zr(OPr)4 or B(OCH3)3 was added. The structure of the hybrid materials was investigated by means of (Fourier transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD), scanning electron microscopy (SEM), (atomic force microscopy (AFM) and nuclear magnetic resonance spectroscopy (NMR). Based on the obtained data, the most probable cross-linking mechanism for the derived gels was proposed. The characterization of texture parameters of both materials was carried out with the use of low-temperature adsorption of nitrogen. Adsorption of Cu(II), Fe(III), Cr(III), Cd(II) and Pb(II) ions on both materials was investigated using multi-component solutions with different concentrations and acidity by means of the batch method. Kinetics of adsorption was also investigated. Pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyze kinetic data. The adsorption was significantly affected by the pH value. Equilibrium data were fitted to linear Langmuir, Freundlich and Dubinin-Radushkevich models and maximum adsorption capacities were calculated.

Synthesis-Morphology-Mechanical Properties Relationships Of Polymer-Silica Nanocomposite Hybrid Materials

1999 ◽  
Vol 576 ◽  
Author(s):  
P. Hajji ◽  
L. David ◽  
J. F. Gerard ◽  
H. Kaddami ◽  
J. P. Pascault ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Resonance Spectroscopy ◽  
Silica Nanocomposites ◽  
X Ray Scattering ◽  
Transmission Electron

ABSTRACTTwo types of polymer-silica nanocomposites have been prepared by undergoing free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) either in the presence of HEMA-functionalized SiO2 nanoparticles (Type 1) or during the simultaneous in situ growing of the silica phase through the acid-catalyzed sol-gel polymerization of tetraethoxysilane (TEOS) (Type 2). Relationships between synthesis, morphology and mechanical properties are discussed mainly on the basis of solid state 29Si nuclear magnetic resonance spectroscopy (NMR), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), and dynamic mechanical analysis (DMA).

scholarly journals Green Synthesis of Mg0.99 Zn0.01O Nanoparticles for the Fabrication of κ-Carrageenan/NaCMC Hydrogel in order to Deliver Catechin

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 861
Author(s):  
Farzaneh Sabbagh ◽  
Khadijeh Kiarostami ◽  
Nadia Mahmoudi Khatir ◽  
Shahabaldin Rezania ◽  
Ida Idayu Muhamad
Keyword(s):  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Decomposition Temperature ◽  
The Body ◽  
Morphological Properties ◽  
Swelling Ratio ◽  
Compression Tests ◽  
Sol Gel Process

Currently, the role of the nanoparticles in the structure of the composites and their benefits for the health of the body is valuable. In this study, the effects of the doping on the structural and morphological properties of the hydrogels using a Mg co-doped ZnO hydrogel, which has been fabricated by the sol–gel process, have been investigated. Then, a hydrogel containing nanoparticle and a hydrogel without any nanoparticles was produced as a control. The hydrogels were loaded with catechin and the related characterization was evolved based on the new structure of the matrices. The Mg0.99Zn0.01O nanoparticles were synthesized using a green synthesis method. To investigate the properties of the nanoparticles, zeta potential and XRD were studied. The field emission scanning electron microscopy (FESEM), FTIR, TGA, swelling Ratio, and compression tests were investigated for the hydrogels. Based on the results, FESEM showed a more compressed structure for hydrogels including nanoparticles rather than the hydrogels without a nanoparticle. The TGA showed a higher decomposition temperature in the hydrogels including nanoparticles. The swelling ratio of hydrogels containing a nanoparticle was higher than the control hydrogel. κ-Carrageenan/ Mg0.99Zn0.01O/NaCMC/Catechin had the highest swelling ratio (44.15%) rather than the κ-Carrageenan/NaCMC (33.22%). Mg0.99Zn0.01O nanoparticles presented a stronger structure of hydrogels in the compression test. It is concluded that the role of the synthesized nanoparticle is critical in the structure of the hydrogel.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

scholarly journals Synthesis and Characterization of N-Substituted Polyether-Block-Amide Copolymers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 773
Author(s):  
Jyun-Yan Ye ◽  
Kuo-Fu Peng ◽  
Yu-Ning Zhang ◽  
Szu-Yuan Huang ◽  
Mong Liang
Keyword(s):  
Titanium Isopropoxide ◽  
Decomposition Temperature ◽  
Phenyl Isocyanate ◽  
Cross Linking ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Melt Polycondensation ◽  
Structural Regularity

A series of N-substituted polyether-block-amide (PEBA-X%) copolymers were prepared by melt polycondensation of nylon-6 prepolymer and polytetramethylene ether glycol at an elevated temperature using titanium isopropoxide as a catalyst. The structure, thermal properties, and crystallinity of PEBA-X% were investigated using nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, wide angle X-ray diffraction, and thermogravimetric analysis. In general, the crystallinity, melting point, and thermal degradation temperature of PEBA-X% decreased as the incorporation of N-methyl functionalized groups increased, owing to the disruption caused to the structural regularity of the copolymer. However, in N-acetyl functionalized analogues, the crystallinity first dropped and then increased because of a new γ form arrangement that developed in the microstructure. After the cross-linking reaction of the N-methyl-substituted derivative, which has electron-donating characteristics, with poly(4,4′-methylenebis(phenyl isocyanate), the decomposition temperature of the resulting polymer significantly increased, whereas no such improvements could be observed in the case of the electro-withdrawing N-acetyl-substituted derivative, because of the incompleteness of its cross-linking reaction.

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