Article
Polymer Science
Anaheed A. Yaseen, Emaad T. B. Al-Tikrity, Emad Yousif, Dina S. Ahmed, Benson M. Kariuki, Gamal A. El-Hiti
Summary: The research focuses on synthesizing and applying new UV photostabilizers for polystyrene, with a specific emphasis on cephalexin Schiff bases. These bases have been shown to effectively stabilize polystyrene against photodegradation, reducing surface damage and weight loss.
Article
Engineering, Chemical
Safaa H. Mohamed, Ayad S. Hameed, Gamal A. El-Hiti, Dina S. Ahmed, Mohammed Kadhom, Mohammed A. Baashen, Muna Bufaroosha, Ahmed A. Ahmed, Emad Yousif
Summary: Three organosilanes were synthesized from the condensation of 4,4 ',4 ''-((phenylsilanetriyl)tris(oxy))tribenzaldehyde and 4-substituted anilines under acidic conditions. These organosilanes showed potential as inhibitors for the photodegradation of PVC, with reduced formation of side products and lower decrease in weight and molecular weight of PVC films after irradiation. The presence of organosilanes also resulted in minimal surface changes of irradiated PVC, indicating their stabilizing effect against long-term ultraviolet light exposure.
Article
Polymer Science
Rafid R. Arraq, Angham G. Hadi, Dina S. Ahmed, Gamal A. El-Hiti, Benson M. Kariuki, Amani A. Husain, Muna Bufaroosha, Emad Yousif
Summary: Poly(vinyl chloride) (PVC) has attractive properties such as low cost, acid and alkali resistance, and ease of molding, but it suffers from aging. Adding tin-cephalexin complexes to PVC can improve its stability to irradiation. This study investigates the effect of these complexes on the photodecomposition of PVC and confirms their role as stabilizers by reducing the rate of photodecomposition.
Article
Materials Science, Characterization & Testing
Emaad T. B. Al-Tikrity, Anaheed A. Yaseen, Emad Yousif, Dina S. Ahmed, Mohammed H. Al-Mashhadani
Summary: This study investigates the use of three new Schiff bases as photo-stabilizers for poly(vinyl chloride) to resist photo-decomposition. The additives were found to reduce the elimination of hydrogen chloride molecules and act as free radical scavengers or peroxide decomposers, thus inhibiting photo-degradation.
POLYMERS & POLYMER COMPOSITES
(2022)
Article
Chemistry, Applied
Ahmed M. Khalil, Reham A. Abdel-Monem, Samira T. Rabie
Summary: Poly(vinyl chloride) loaded with various contents of Moringa oleifera leaves extract exhibited changes in structure, rheological and mechanical properties, antibacterial efficiency, as well as photostability. The thermal stability of PVC was also affected by adding Moringa oleifera extract.
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
(2021)
Review
Polymer Science
Krzysztof Lewandowski, Katarzyna Skorczewska
Summary: This article provides a literature review on the recycling of PVC, including mechanical recycling and feedstock recycling methods. It also introduces the characteristics of PVC and its potential in the circular economy.
Article
Chemistry, Organic
Inaia O. Rocha, Yuri G. Kappenberg, Wilian C. Rosa, Clarissa P. Frizzo, Nilo Zanatta, Marcos A. P. Martins, Isadora Tisoco, Bernardo A. Iglesias, Helio G. Bonacorso
Summary: A new series of Schiff bases were synthesized with good yields and exhibited low to good quantum fluorescence yield values in various solvents. These compounds showed higher Stokes shifts in more polar solvents and presented good stability under white-LED irradiation conditions.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Polymer Science
Carlos M. R. Abreu, Talita C. Rezende, Armenio C. Serra, Ana C. Fonseca, Rebecca Braslau, Jorge F. J. Coelho
Summary: A new strategy of internal plasticization of PVC was achieved by copolymerization of VC with n-BA and OEOA. The effect of solvent, initiator, polymerization temperature, and VC/n-BA/OEOA ratios on Tg of the resulting copolymers was investigated. The internally plasticized PVC copolymers showed lower Tg values than predicted, indicating effective plasticization of PVC. Under optimized conditions, different degrees of internal plasticization could be achieved by varying the initial monomer ratio. Importantly, the plasticizing moieties were covalently bonded to the polymer, resulting in no migration during extraction.
Article
Polymer Science
Jolanta Tomaszewska, Tomasz Sterzynski, Damian Walczak
Summary: The study investigated the thermal stability of PVC with 1 wt % of spherical porous nanosilica prepared by roll milling at various processing times. The addition of porous nanosilica was found to improve thermal stability by absorbing HCl gas produced during dehydrochlorination reaction, resulting in minor color changes and lower evolution of hydrogen chloride gas. The results showed that TGA measurements were not sensitive enough to detect PVC degradation at processing conditions below 220 degrees C.
Article
Chemistry, Applied
Mohammed Kadhom, Alaa Mohammed, Hassan Ghani, Amer Adnan Hasan, Omar G. Mousa, Roaa T. Abdulla, Wedad H. Al-Dahhan, Mohammed H. Al-Mashhadani, Rahimi M. Yusop, Emad Yousif
Summary: The photo degradation of a PVC film with Schiff bases was investigated by comparing it with a blank PVC film. A PVC film containing novel Schiff's bases was synthesized and used as a photostabilizer for PVC. The impact of Schiff bases on PVC films was studied by calculating the photodecomposition rate constants after UV irradiation for 300 hours and monitoring the evolution of functional groups using FTIR spectra, SEM, and AFM.
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
(2023)
Article
Polymer Science
Mohammed Alwan Farhan, Zahraa S. Al-Garawi, Wassan Baqir Ali, Olfat Abaid Nief
Summary: This study explored the potential of using PVC and PS polymers in urine microscopic examination. The results showed that PVC was able to preserve the urine components for a long time, while PS was not. Therefore, PVC was considered as an effective polymer for protecting urine compositions.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Polymer Science
Carmen Mijangos, Itxaso Calafel, Antxon Santamaria
Summary: Poly(vinyl chloride) (PVC) is a widely used commodity polymer that is continuously evolving. It has recently been demonstrated that PVC is suitable for extrusion-based 3D printing, allowing the production of tailored flexible and ductile PVC objects. This article describes the important characteristics of PVC, including production and applications, as well as its drawbacks of thermal degradation and plasticizer exudation. The article also discusses recent efforts and advances in overcoming these limitations and developing new applications through modification reactions and the use of PVC formulations in additive manufacturing.
Article
Chemistry, Applied
Elvis Lopes Brito, Bertrand Willocq, Frederic Boschet, Nicholas Ballard
Summary: Although PVC is usually produced industrially by emulsion and suspension polymerization, it is rarely used directly as an aqueous polymer dispersion. However, this study shows that it is possible to produce high PVC content latexes with suitable particle morphology and size distribution for direct film formation. Hybrid PVC/acrylic latexes with a core-shell structure are produced by semi-batch emulsion polymerization using a preformed PVC latex as a seed. By using a bimodal particle size distribution, the packing efficiency of the PVC domains is increased, enabling film formation at room temperature with high PVC content.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Chemistry, Multidisciplinary
Nancy G. Bush, Mikiyas K. Assefa, Selin Bac, Shaama Mallikarjun Sharada, Megan E. Fieser
Summary: In the presence of (xantphos)RhCl catalyst, reaction of poly(vinyl chloride) (PVC) with triethyl silane in THF leads to partial reduction of PVC via hydrodechlorination. Increasing catalyst loading or using N,N-dimethylacetamide (DMA) as a solvent decreases the selectivity for hydrodechlorination. Reaction of PVC with sodium formate in THF affords excellent selectivity for hydrodechlorination along with complete PVC dechlorination, while higher catalyst loadings are required. In contrast, reaction of PVC with NaH in DMA exhibits good selectivity for dehydrochlorination and higher reaction rates.
MATERIALS HORIZONS
(2023)
Article
Polymer Science
Raquel Thomaz, Yvette Ngono-Ravache, Daniel Severin, Christina Trautmann, Ricardo M. Papaleo
Summary: This study investigates the thinning and surface morphology changes induced by high-energy ion bombardment in PMMA and PVC thin films. It is found that there is a supralinear scaling between the thinning cross sections and the electronic stopping power of the ions, with a much enhanced thinning efficiency for the swift heavy ions. The initial thickness of the films has minimal impact on the thinning process.
Article
Chemistry, Inorganic & Nuclear
Benson M. Kariuki, Hanan A. Mohamed, Bakr F. Abdel-Wahab, Gamal A. El-Hiti
Summary: Unexpected ring closure of compound 3 under the action of sulfuric acid at room temperature resulted in the formation of compound 4 with a yield of 75%. The synthesized benzenesulfonic acid showed inhibitory activity against both Listeria monocytogenes and Escherichia coli, which was comparable to ampicillin and vancomycin.
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
(2023)
Article
Multidisciplinary Sciences
Essam S. Almutleb, Gamal A. El-Hiti, Hesham A. Al-Dawas, Mohammed K. Alanzi, Mohammed Alquwayi, Abdullah G. Alotaibi, Mashaaer A. Baashen, Basal H. Altoaimi, Saud A. Alanazi, Ali M. Masmali
Summary: The study investigated the effect of adding low concentrations of sodium chloride (NaCl) and potassium chloride (KCl) solutions on tear ferning (TF) patterns. The results showed significant improvements in TF grades after the addition of NaCl and KCl solutions to tear samples. However, there was a significant difference in TF grades when NaCl and KCl solutions were added. Conclusion: Adding low concentrations of NaCl and KCl solutions can significantly improve the TF grades of human tears.
Article
Polymer Science
Rafid R. Arraq, Angham G. Hadi, Dina S. Ahmed, Gamal A. El-Hiti, Benson M. Kariuki, Amani A. Husain, Muna Bufaroosha, Emad Yousif
Summary: Poly(vinyl chloride) (PVC) has attractive properties such as low cost, acid and alkali resistance, and ease of molding, but it suffers from aging. Adding tin-cephalexin complexes to PVC can improve its stability to irradiation. This study investigates the effect of these complexes on the photodecomposition of PVC and confirms their role as stabilizers by reducing the rate of photodecomposition.
Article
Biochemistry & Molecular Biology
Abdelmoujoud Faris, Hanine Hadni, Basil A. Saleh, Hadjer Khelfaoui, Dalal Harkati, Hassan Ait Ahsaine, Menana Elhallaoui, Gamal A. El-Hiti
Summary: In this study, twenty-seven 1,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidines were tested as potential selective inhibitors of JAK3. Molecular modeling methods and statistical analysis were used to evaluate the activity and predictive ability of the tested compounds. The results showed that compounds containing the acrylic aldehyde moiety had irreversible interaction with the active sites of JAK3, indicating their potential as anti-JAK3 inhibitors for rheumatoid arthritis treatment.
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
(2023)
Review
Medicine, General & Internal
Kholoud Ahmad Bokhary, Razan Ibrahim Alsabih, Gamal Abdelrahman El-Hiti
Summary: This narrative review aimed to investigate the efficiency of binocular treatment for amblyopic children and compare it with standard methods. Literature search was conducted to identify studies in the field of binocular treatment for amblyopia, and the results showed that binocular treatment improved visual acuity and binocular function, reducing suppression depth extent and increasing stereopsis for amblyopic children.
JOURNAL OF THE PAKISTAN MEDICAL ASSOCIATION
(2023)
Article
Chemistry, Organic
Bakr F. Abdel-Wahab, Abdelbasset A. Farahat, Benson M. Kariuki, Gamal A. El-Hiti
Summary: The reaction of 1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one (1) with excess hydroxylamine hydrochloride (2 mole equivalents) in dry ethanol yielded (E)-1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one oxime (2) in 86% yield. The structure of the new heterocycle 2 was confirmed using nuclear magnetic resonance spectroscopy, single crystal X-ray, and elemental analysis.
Article
Chemistry, Organic
Bakr F. Abdel-Wahab, Mohamed S. Bekheit, Benson M. Kariuki, Gamal A. El-Hiti
Summary: Equimolar equivalents of 1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbohydrazide (1) and 2-acetylbenzofuran (2) reacted in anhydrous ethanol containing a catalytic amount of concentrated hydrochloric acid under reflux for 2 h to give (E)-N'-(1-(benzofuran-2-yl)ethylidene)-1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbohydrazide (3) in 86% yield. The structure of compound 3 was confirmed using nuclear magnetic resonance and X-ray diffraction.
Article
Chemistry, Organic
Bakr F. Abdel-Wahab, Hanan A. Mohamed, Benson M. Kariuki, Gamal A. El-Hiti
Summary: A 1:1 mixture of compound 1 and compound 2 reacted under reflux in anhydrous ethanol in the presence of piperidine as a catalyst for 4 hours, resulting in the formation of compound 3 with 82% yield. The structure of the newly synthesized heterocycle was confirmed using X-ray diffraction and spectral analyses.
Article
Chemistry, Analytical
Keith Smith, Xiaojing Mu, Zhaoqiang Li, J. Stuart Woodhead, Gamal A. El-Hiti
Summary: Two new acridinium triflates with a 2-(succinimidyloxycarbonyl)ethyl side arm have been synthesized and characterized. The chemiluminescence properties and hydrolytic stabilities of the newly synthesized acridinium triflates were investigated.
Article
Chemistry, Physical
Sunil Chauhan, Shweta Rai, Soumya Pandit, Arpita Roy, Amel Gacem, Gamal A. El-Hiti, Krishna Kumar Yadav, Balasubramani Ravindran, Ji-Kwang Cheon, Byong-Hun Jeon
Summary: The Microbial Desalination Cell (MDC) is a new method for desalinating water and generating energy. The main issue with the technology is the low power generation during the oxygen reduction reaction (ORR). In this study, neodymium-doped zinc oxide nanoparticles were used as a highly active cathode catalyst to improve the performance of the MDC. The Nd-doped ZnO catalyst showed higher desalination efficiency and power density compared to the MDC without a catalyst.
Article
Crystallography
Bakr F. Abdel-Wahab, Benson M. Kariuki, Hanan A. Mohamed, Gamal A. El-Hiti
Summary: A one-pot reaction was performed without any catalysts to react 4-methoxyaniline, phenyl isothiocyanate, and 2-bromoacetylbenzofuran in absolute ethanol, resulting in a yield of 83% for the synthesis of 4-(benzofuran-2-yl)-3-(4-methoxyphenyl)-N-phenylthiazol-2(3H)-imine. Under similar conditions, a mixture of 4-(benzofuran-2-yl)-3-(4-fluorophenyl)-N-phenylthiazol-2(3H)-imine and 4-(benzofuran-2-yl)-N-(4-fluorophenyl)-3-phenylthiazol-2(3H)-imine was obtained from the reaction of 4-fluoroaniline with a overall yield of 73%. Structural determination of the products was conducted using single-crystal diffraction after recrystallization from dimethylformamide.
Article
Multidisciplinary Sciences
Essam S. Almutleb, Basal H. Altoaimi, Gamal A. El-Hiti, Abdullah G. Alotaibi, Mashaaer A. Baashen, Saud A. Alanazi, Ali M. Masmali
Summary: The research aims to examine the impact of adding dilute solutions of sodium chloride and potassium chloride on the tear ferning patterns in artificial tears. The results demonstrate that adding these solutions or a combination of both significantly improves the tear ferning grades of artificial tears.
JOURNAL OF KING SAUD UNIVERSITY SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Noor Emad, Gamal A. El-Hiti, Emad Yousif, Dina S. Ahmed, Benson M. Kariuki
Summary: Considerable research is being done to reduce atmospheric CO2 levels by capturing and storing the gas using adsorbents. Synthesizing new materials, like the sulfamethoxazole-metal complexes, for CO2 storage and investigating their absorption capabilities has shown promise. The cobalt-containing complex had the highest CO2 storage capacity due to its specific physical properties, making it more effective compared to the nickel and copper complexes.
RESULTS IN CHEMISTRY
(2023)
Article
Chemistry, Physical
Bakr F. Abdel-Wahab, Benson M. Kariuki, Hanan A. Mohamed, Mohamed S. Bekheit, Hanem M. Awad, Gamal A. El-Hiti
Summary: The synthesis of heterocycles containing 1,2,3-triazole and pyrazole moieties has been explored for their potential applications in the agrochemical and pharmaceutical fields. These heterocycles have shown promising anti-proliferation properties against cancer cells. In this study, several new 1H-1,2,3-triazole derivatives were successfully synthesized using simple procedures, and their activity against different types of cancer cells and normal cells was evaluated.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Multidisciplinary
Noor Emad, Gamal A. El-Hiti, Emad Yousif, Dina S. Ahmed, Marwa Fadhil, Benson M. Kariuki
Summary: This study reports the synthesis of a new material for storing carbon emissions, particularly carbon dioxide. The metal complexes synthesized have large surface areas and pore volumes, and exhibit high carbon dioxide storage capacity.
RESULTS IN CHEMISTRY
(2023)
