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- Abd El-Hakim, Abou El Fettouh Abd El Moneim, et al.
(författare)
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Improving the mechanical and thermal properties of chlorinated poly(vinyl chloride) by incorporating modified CaCO3 nanoparticles as a filler
- 2019
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Ingår i: Turkish journal of chemistry. - : The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS. - 1300-0527 .- 1303-6130. ; 43:3, s. 750-759
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Tidskriftsartikel (refereegranskat)abstract
- Chlorinated poly(vinyl chloride) (CPVC)/calcium carbonate nanocomposites were successfully prepared by the incorporation of calcium carbonate (CaCO3) nanoparticles into the CPVC matrix. The compatibility between the two phases was obtained by surface modification of the CaCO3 nanoparticles with stearic acid, leading to improved material performance. The effects of the addition of different amounts of CaCO3 nanoparticles to the CPVC on the thermal, mechanical, and morphological characteristics of the CPVC/CaCO3 nanocomposites were investigated. The thermal stability of the CPVC/CaCO3 nanocomposites was evaluated by thermogravimetric analysis and differential scanning calorimetry. In addition, the surface texture of the CPVC and the dispersion of the CaCO3 were evaluated using scanning electron microscopy. Important enhancements in the thermal and mechanical properties of the modified CPVC/CaCO3 nanocomposites were obtained by incorporating different amounts (2.00%, 3.75%, and 5.75%) of surface-modified CaCO3 nanoparticles within the CPVC polymer matrix. The results reveal that 3.75% of CaCO3 was the optimum amount, where the CPVC/CaCO3 nanocomposite shows the highest impact strength, the highest tensile strength, the highest thermal stability, and the lowest elongation percentage. Replacement of the commercial impact modifier used in industry with the prepared surface-modified CaCO3 nanoparticles for the development of CPVC was successfully achieved.
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- Taha, Rania H., et al.
(författare)
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Synthesis and characterization of a symmetrically substituted cyclodiphosph(V)azane ligand (H4L') and its transition metal complexes for antimicrobial and antitumor investigation
- 2020
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Ingår i: Egyptian Journal of Chemistry. - : Egypts Presidential Specialized Council for Education and Scientific Research. - 0449-2285 .- 2357-0245. ; 63:8, s. 3097-3107
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Tidskriftsartikel (refereegranskat)abstract
- A NEW ligand of geminal cyclodiphosph(V)azane derivatives, 1,3-di-[N/-2,6-dimethoxyLl-pyrimidnylsulfanilamide12,4-di-IN/-2-quinoxalinylsulfanilamidel-2,4dichloroc- yelodiphosph(V)azane (H4L') was prepared. The ligand and its related complexes were characterized by different physicochemical techniques, namely; IR, UV vis, mass, 'H NMR, molar conductance, magnetic, solid reflectance, and thermal analysis The spectral data revealed that the ligand behaves as ionic in nature and coordinated to the metal ions via enolic-OH of sulphonamide group and pyrimidine N. The molar conductance data reveal that the complexes were electrolytes, while UV vis, solid reflectance and magnetic moment data have been shown that the complexes have octahedral geometry. The thermal behavior of the complexes was also studied. The ligand and its metal complexes showed a high to moderate antimicrobial activities against deferent strains of bacteria and fungi, also showed anticancer activity against colon carcinoma HCT116.
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- Yahia, Mohamed, et al.
(författare)
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Effect of incorporating different ZIF-8 crystal sizes in the polymer of intrinsic microporosity, PIM-1, for CO2/CH4 separation
- 2021
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Ingår i: Microporous and Mesoporous Materials. - : Elsevier. - 1387-1811 .- 1873-3093. ; 312
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Tidskriftsartikel (refereegranskat)abstract
- Effective and economical carbon dioxide-methane separation (CO2/CH4) is highly desirable in several industries such as sweetening natural gases and renewable natural gas (RNG) from biogas and landfills. Among the different separation technologies, membrane separation has been shown to have lower cost of production and lower CH4 losses. In this study, Zeolitic Imidazole Frameworks (ZIF-8) crystals with sizes varying from 45 nm to 450 nm were synthesized and incorporated in the polymer of intrinsic microporosity, PIM-1, to form mixed matrix membranes (MMMs). The structure, morphology, and physicochemical properties of the MMMs were characterized by 1H NMR, FTIR, XRD, TGA, and SEM. ZIF-8 crystal size was controlled using the concentration of sodium formate. The influence of the ZIF-8 crystal size on MMMs was studied by sorption, gas permeability, and aging of the membranes. The MMMs with ZIF-8 crystals of 120 nm particle diameter yielded the greatest improvement in gas transport properties; the CO2/CH4 selectivity-CO2 permeability was 11.4 and 9700 Barrer compared to PIM-1 with 6.4 and 9300 Barrer respectively. The former is near the Robeson 2008 upper bound, while PIM-1 is on the 1991 upper bound. After 40 days of aging, selectivity increased and permeability decreased; the changes were parallel to the Robeson upper bounds indicating increased polymer packing and diffusivity selectivity.
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- Guiver, Michael D., et al.
(författare)
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Gas Transport in a Polymer of Intrinsic Microporosity (PIM-1) Substituted with Pseudo-Ionic Liquid Tetrazole-Type Structures
- 2020
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 53:20, s. 8951-8959
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Tidskriftsartikel (refereegranskat)abstract
- We report a side group modification strategy to tailor the structure of a polymer of intrinsic microporosity (PIM-1). PIM-1 with an average of similar to 50% of the repeat units converted to tetrazole is prepared, and a subsequent reaction then introduces three types of pseudo-ionic liquid tetrazole-like structures (PIM-1-ILx). The presence of pseudo-ionic liquid functional groups in the PIM-1 structure increases gas selectivities for O-2/N-2 and CO2/N-2, while it decreases pure-gas permeabilities. The overall gas separation performance of PIM-1-ILx is close to the 2008 Robeson upper bound. Since the tetrazoles are versatile groups for building a wide variety of ionic liquids, the modification method can be expanded to explore a broad spectrum of functional groups.
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- Jimenez-Ruiz, Ernesto, et al.
(författare)
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Introducing the HOBBIT platform into the Ontology Alignment Evaluation Campaign
- 2018
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Ingår i: Proceedings of the 13th International Workshop on Ontology Matching. - Aachen, Germany : CEUR Workshop Proceedings. ; , s. 49-60
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Konferensbidrag (refereegranskat)abstract
- This paper describes the Ontology Alignment Evaluation Initiative 2017.5 pre-campaign. Like in 2012, when we transitioned the evaluation to the SEALS platform, we have also conducted a pre-campaign to assess the feasibility of moving to the HOBBIT platform. We report the experiences of this pre-campaign and discuss the future steps for the OAEI.
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- Wang, Wei, et al.
(författare)
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Carbon-supported phosphatized CuNi nanoparticle catalysts for hydrazine electrooxidation
- 2019
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 44:21, s. 10637-10645
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Tidskriftsartikel (refereegranskat)abstract
- Developing non-noble metal catalysts with high performance to reduce the cost of hydrazine fuel cells is urgent. Herein, in this study, a series of carbon-supported phosphatized CuNi catalysts (P--CuxNiy/C) are designed for hydrazine oxidation reaction (HzOR) via high temperature phosphating process. Among them, the P-Cu2Ni/C is found to be a promising candidate for hydrazine electrooxidation. Electrochemical measurement results indicate that the P-Cu2Ni/C catalyst exhibits higher catalytic activity and stability for HzOR in comparison with P-CuNi/C, P-CuNi2/C, Cu2Ni/C, Cu/C and Ni/C catalysts. Additionally, HzOR kinetics are also investigated, and it proves that hydrazine electrooxidation on P-Cu2Ni/C is a diffusion controlled irreversible process. Meanwhile, physical characterization reveals that the catalysts have doped phosphorus successfully. All results demonstrate that as-prepared P-Cu2Ni/C catalyst is a promising electrocatalyst for direct hydrazine fuel cells.
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- Yahia, Mohamed, et al.
(författare)
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Linear Main-Chain 1,2,4-Triazolium Poly(ionic liquid)s : Single-Step Synthesis and Stabilization of Cellulose Nanocrystals
- 2019
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Ingår i: ACS Macro Letters. - : American Chemical Society (ACS). - 2161-1653. ; 8:10, s. 1372-1377
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Tidskriftsartikel (refereegranskat)abstract
- Linear main-chain 1,2,4-triazolium-based poly(ionic liquid)s (PILs) were synthesized in this contribution. The polymerization process is experimentally very simple and involves only a single-step polycondensation of a commercially available monomer in DMSO as solvent at 120 degrees C. Their thermal stability and solubility were analyzed in terms of different counteranions. Due to the ease of this synthetic route, it was readily applied to graft onto sulfonated cellulose nanocrystals (CNCs) via a one-step in situ polymerization. The as synthesized PIL@CNC hybrid colloids exhibit adaptive dispensability in water and organic solvents.
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- Yahia, Mohamed, et al.
(författare)
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Replacing benzyl chloride with a lignin-degradation product in cellulose etherification decreases the melting point
- 2023
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Ingår i: BioResources. - : North Carolina State University. - 1930-2126. ; 18:1, s. 161-174
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Tidskriftsartikel (refereegranskat)abstract
- A cellulose ether that is easier to melt than benzyl cellulose was produced from the lignin degradation product veratryl alcohol. Veratryl chloride and bromide were synthesized from the alcohol, and these two chemicals were used to react with Avicel® cellulose to form the novel cellulose ether veratryl cellulose (VC). Spectroscopic characterisation techniques (1H NMR, FTIR) indicated the successful conversion of Avicel® cellulose to the cellulose ether VC, by both routes, at a degree of substitution of 1.4 to 1.6. Melting measurements of the VC samples showed a gradual softening from approximately 110 °C; the VC was melted below 200 °C. XRD analysis confirmed that the chemical treatments affect the degree of crystallinity. Size exclusion chromatography results showed that the products differ remarkably in molecular weight. The VC synthesized with veratryl chloride degraded almost twice as much as when veratryl bromide were used. The cellulose ethers were soluble in DMSO, DMAc, and CHCl3.
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