Article
Chemistry, Physical
Xu-ling Wang, Yan-ping Zhang, Fei Wang, Li Pan, Bin Wang, Yue-sheng Li
Summary: A series of methyl nickel complexes with phosphino-naphtholate chelate ligands have been designed and synthesized with high activity towards ethylene polymerization and ethylene/unsaturated acid ester copolymerization. These catalysts show outstanding catalytic activities, achieving high productivity in both ethylene polymerization and ethylene/methyl acrylate copolymerization.
Review
Chemistry, Multidisciplinary
Chen Tan, Min Chen, Changle Chen
Summary: Transition metal-catalyzed olefin-polar monomer copolymerization has the potential to synthesize polar group-functionalized polyolefin materials. However, the traditional trial-and-error approach is challenging and time-consuming. Recent 'catalyst + X' strategies have emerged, which utilize the interactions between the catalyst and other components in the copolymerization system to influence the reaction and resulting material properties. This review summarizes selected examples of these strategies and discusses future perspectives.
TRENDS IN CHEMISTRY
(2023)
Article
Polymer Science
Chen Tan, Chen Zou, Changle Chen
Summary: Polyethylenes have wide applications due to their superior properties, and incorporating polar functional groups into their backbone can greatly enhance important properties and broaden their applications. However, the research on material properties of transition-metal-catalyzed ethylene-polar monomer copolymers has only recently started to receive attention. This Perspective summarizes recent advances in surface and compatibility properties, as well as custom-made properties, resulting from the incorporation of polar groups.
Article
Chemistry, Multidisciplinary
Chen Tan, Chen Zou, Changle Chen
Summary: The study introduces an ionic cluster strategy for controlling product morphology and improving catalytic copolymerization performance in the synthesis of polar-functionalized polyolefins. This strategy is versatile, enhancing thermal stability of catalysts at high temperatures and enabling the homopolymerization of polar-functionalized olefins. It also results in polyolefin composites with tunable mechanical properties, showing potential as compatibilizing agents for polyolefin mixtures with other polymers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Multidisciplinary
Stephen L. J. Luckham, Kyoko Nozaki
Summary: Polyolefins, including polyethylene (PE) and polypropylene (PP), are widely used in consumer products and can be enhanced by forming composites with other materials. To improve their compatibility with other materials, the inclusion of polar functionalities in the polymer chain is essential. Different transition metal catalysts have varying effects on achieving this goal, with late transition metal catalysts being more suitable for reactions with polar comonomers.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Article
Chemistry, Applied
Hongwei Peng, Shuaikang Li, Gen Li, Shengyu Dai, Mingjun Ji, Zhe Liu, Lihua Guo
Summary: The addition of bulky rotation-restricted substituents into iminopyridyl Ni (II) and Pd (II) catalysts was shown to effectively retard chain transfer, resulting in high molecular weight polyethylene or ethylene-MA copolymers with high MA incorporation ratio. Systematic studies on the (co)polymerization behavior as a function of rotation-restricted substituent variations led to the successful synthesis of various molecular weight polyethylene and ethylene-MA copolymer products.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Polymer Science
Wenbing Wang, Min Chen, Wenmin Pang, Yougui Li, Chen Zou, Changle Chen
Summary: Investigated two groups of norbornene comonomers: one provides additional active sites for sulfur vulcanization and the other can alter the non-polar nature of polyolefin materials. Palladium-catalyzed terpolymerization of ethylene with these comonomers yields polar-functionalized polyolefin elastomers with high molecular weight and comonomer content, possessing excellent mechanical and elastic properties.
Article
Chemistry, Physical
Hu Zhang, Zhaoyu Zhang, Zhengguo Cai, Mingyuan Li, Zhen Liu
Summary: The development of heterogeneous late transition metal-catalyzed olefin (co)polymerization is challenging. This study reports the preparation of heterogeneous anilinonaphthoquinone nickel and palladium catalysts. The nickel catalyst exhibits very high activity and can produce high-molecular-weight semicrystalline polyethylenes. The polymerization behavior is influenced by the electron density of the metal center and the Lewis acidity of the alkylaluminum. The palladium catalyst promotes copolymerization of ethylene with methyl acrylate or polar norbornene derivatives.
Article
Chemistry, Physical
Hu Zhang, Zhaoyu Zhang, Zhengguo Cai, Mingyuan Li, Zhen Liu
Summary: The development of heterogeneous late transition metal catalysts for olefin (co)polymerization has been investigated. The preparation of heterogeneous anilinonaphthoquinone nickel and palladium catalysts has been reported. The nickel catalyst showed high activity for ethylene polymerization, producing high-molecular-weight polyethylenes with well-regulated morphologies. The palladium catalyst promoted copolymerization of ethylene with commercial methyl acrylate or norbornene derivatives, leading to functionalized polyethylene and cyclic olefin copolymers.
Article
Polymer Science
Jian Xia, Ying-Feng Han, Shuqing Kou, Yixin Zhang, Zhongbao Jian
Summary: A series of flexible cyclohexyl/rigid aromatic phosphine-sulfonate palladium and nickel catalysts were designed and synthesized in this study. The steric effect of alkoxy substituents in the catalysts plays an important role in tuning polymer molecular weight and co-monomer incorporation in copolymers. The research demonstrated the high molecular weight and catalytic activity achieved by the catalysts in ethylene polymerization and copolymerization with polar monomers.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Polymer Science
Chaoqun Wang, Xiaohui Kang, Hongliang Mu, Zhongbao Jian
Summary: This study investigates the effect of polar solvents on ethylene polymerization. The results show that the use of tetrahydrofuran and 1,4-dioxane as polar solvents can increase the molecular weight, turnover frequency, and narrow the molecular weight distribution of the polymer, while maintaining the branching density. This promotes ethylene polymerization in a "living" manner and generates ultrahigh molecular weight polyethylene.
Article
Chemistry, Multidisciplinary
Fei Wang, Xu-ling Wang, Li Pan, Bin Wang, Yue-Sheng Li
Summary: Direct copolymerization of ethylene and allyl acrylate using a bulky phosphino-phenolate nickel catalyst resulted in high-molecular-weight copolymers with polar ring structures. The obtained copolymers exhibited multiplex structures with noncyclic units containing allyl and acrylate moieties, as well as cyclic units of gamma-butyrolactones and delta-valerolactone. The content of different structural units in the copolymer could be adjusted by varying the concentration of the comonomer. Additionally, the nickel-based catalyst showed significantly enhanced copolymer molecular weights compared to the palladium-based catalyst under the same conditions.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Chen Zou, Quan Wang, Guifu Si, Changle Chen
Summary: Polar bimodal polyethylene is demonstrated as a potential solution to the trade-off between catalytic activity and polymer molecular weight caused by polar groups in catalysts. Three synthetic routes are investigated to achieve high miscibility between the polar and non-polar fractions, with the co-anchoring strategy being the most effective. This produces polyolefin materials with excellent properties for various applications.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Weiqing Lu, Hui Wang, Weigang Fan, Shengyu Dai
Summary: In this study, a bulky hybrid catalyst was designed and synthesized, which exhibited high activity and efficient copolymerization performance in the polymerization of ethylene. The hybrid catalyst generated highly branched polyethylenes with high molecular weights, showing advantages over the corresponding symmetrical catalysts.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Mahsa Karimi, Hassan Arabi, Samahe Sadjadi
Summary: The use of catalysts in olefin homo- and copolymerization has become increasingly important. Nickel and palladium-based complexes with symmetrical cationic a-diimine and non-symmetrical neutral phosphine-sulfonate ligands have been widely utilized as olefin (co)polymerization catalysts. The unique properties of phosphine-sulfonate-based catalysts have attracted significant attention from researchers.
JOURNAL OF CATALYSIS
(2022)
Article
Materials Science, Composites
Yunusa Umar, S. K. Manirul Haque, Mamdouh Al-Harthi, Zakariya Sadique, Omar Ashwaq, Edwin Obra, P. A. Sreekumar
Summary: In this study, composites were prepared by incorporating powdered waste date palm midribs into polyvinyl alcohol (PVA). The addition of date palm midribs as filler enhanced the tensile modulus and thermal stability of the composites.
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Mamdouh A. Al-Harthi, Manwar Hussain
Summary: Nanocomposites of PVDF with graphene nanoflakes were prepared using two different methods, and their thermal and mechanical properties were evaluated. The addition of graphene improved the thermal stability and mechanical properties of the nanocomposites, with better performance observed in the composites prepared by mix-melting method.
Article
Construction & Building Technology
Muhammad Nasir, Muhammad Arif Aziz, Mukarram Zubair, Noman Ashraf, Tag Nasreldin Hussein, Moath Khalid Allubli, Mohammad Saood Manzar, Walid Al-Kutti, Mamdouh A. Al-Harthi
Summary: This study investigated the incorporation of cellulose nanocrystals (CNCs) with different properties into mortar, and found that the mortar with CNCs synthesized under mild acid hydrolysis conditions (C1) showed the best performance. C1-based mortar exhibited improved compressive strength, flexural strength, and thermal conductivity, as well as reduced volume of permeable voids compared to the CNC-free mortar. The enhanced performance of C1 specimens was attributed to the increased precipitation and crystallinity of the CNCs, as well as the intertwining of major elements and crack-bridging effects in the cementitious composites.
JOURNAL OF BUILDING ENGINEERING
(2022)
Review
Energy & Fuels
Arafat Husain, Mamdouh A. Al-Harthi
Summary: Treatment of oilfield wastewater, typically in the form of emulsion, is a significant environmental concern. Chemical demulsification is the most effective method to separate oil and water, especially at high temperatures. This review discusses recent advancements and modifications of demulsifiers, including triblock EO-PO copolymers, non-biodegradable polymers, and branched copolymers, as well as upcoming alternatives like nanomaterial demulsifiers and ionic liquids. Factors such as chemical structure and temperature play important roles in demulsifier selection and efficiency. Additionally, the article explores the whole mechanism of chemical demulsification and introduces emerging chemical treatment methods.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Physical
Radwa A. El-Salamony, Ahmed S. Al-Fatesh, Kenit Acharya, Abdulaziz A. M. Abahussain, Abdulaziz Bagabas, Nadavala Siva Kumar, Ahmed A. Ibrahim, Wasim Ullah Khan, Rawesh Kumar
Summary: Samarium oxide (Sm2O3) is a versatile surface for CO2 and H-2 interaction and conversion. Different catalysts supported by samarium oxide, including Ni, Co-Ni, and Ru-Ni, were tested for CO2 methanation and characterized through multiple techniques. The results showed that the selectivity of CH4 was around 98%, while the selectivity of CO varied depending on the catalyst composition. Co-impregnation of cobalt with nickel over Sm2O3 resulted in higher CO selectivity, while co-impregnation of ruthenium and nickel led to carbonate species and high CH4 selectivity.
Article
Chemistry, Physical
Majid L. Balogun, Wasim Ullah Khan, M. Nasiruzzaman Shaikh, Sagir Adamu, Abeer S. Arjah, Saad A. Al-Bogami, Sameer Al-Ghamdi, Mohammad M. Hossain
Summary: A redox catalyst with MoO3 loaded on CaMnO3 perovskite was used for chemical-looping oxidative dehydrogenation (ODH) of propane to produce propylene. This catalyst showed a lower energy consumption and minimum CO2 emission, making it environmentally friendly. Experimental results indicated that MoO3 incorporation minimized the release of surface oxygen and improved propylene selectivity. The catalyst exhibited stable activity in successive redox cycles, and the addition of MoO3 enhanced propylene yield and selectivity by promoting the formation of lattice oxygen.
APPLIED CATALYSIS A-GENERAL
(2023)
Article
Engineering, Chemical
Md Khairul Bahar, Hassam Mazhar, Wasim Ullah Khan, Mamdouh Ahmed Al-Harthi
Summary: This paper reports the in situ synthesis of ethylene-propylene (EP) copolymer, its terpolymer with styrene, and composites with nickel-chromium (NiCr) layered double hydroxide (LDH), as well as their thermal properties. The addition of styrene significantly increased the yield of EP, but had negative effects on crystallinity, melting temperature, and thermal stability. Incorporation of NiCr LDH adversely affected the thermal stability of the terpolymer, but ultrasonication treatment improved it.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Review
Chemistry, Inorganic & Nuclear
Ijaz Hussain, Hassan Alasiri, Wasim Ullah Khan, Khalid Alhooshani
Summary: The need for energy has increased drastically since the industrial revolution, resulting in higher atmospheric CO2 concentrations. As a global priority, effective solutions to reduce CO2 emissions are being developed and implemented. Electrochemical reduction (ECR) is an advanced method for converting CO2 into valuable byproducts like methanol. However, the low selectivity and activity of electrocatalytic systems remain major challenges in CO2-ECR technology, emphasizing the importance of evaluating the state of the art in manufacturing electrocatalytic systems.
COORDINATION CHEMISTRY REVIEWS
(2023)
Article
Chemistry, Physical
Wasim Ullah Khan, Ahmed Al Shoaibi, Srinivasakannan Chandrasekar, Mohammad M. Hossain
Summary: Nickel and cobalt-based titania-supported bimetallic catalysts with varying metal loading were synthesized. High-loading catalysts showed higher activity and stability, with 25NCT catalyst exhibiting the highest methane conversion and carbon yield. The catalyst's enhanced activity can be attributed to its higher specific surface area and the formation of carbon nanotubes through tip-growth and base-growth mechanisms.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Polymer Science
Hassam Mazhar, Wasim Ullah Khan, Farrukh Shehzad, Sung-Gil Hong, Mamdouh A. Al-Harthi
Summary: This study presents a new method for the ultrasonication-assisted in situ synthesis of ethylene-propylene-1-hexene (EPH)-ZnAl-layered double hydroxide (LDH) nanocomposites. The ultrasonication treatment resulted in the exfoliation of LDH into few layers or thinner nanosheets, which had a positive impact on the catalytic activity and formation of active sites. Additionally, the highly dispersed ZnAl sheet in the EPH polymer matrices significantly improved its thermomechanical properties, as evidenced by thermogravimetric and dynamic mechanical analysis. The introduction of less than 0.25 wt% filler content led to a substantial enhancement in thermal stability and average activation energy of thermal degradation.
JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
(2023)
Review
Energy & Fuels
Ahmed S. Al-Fatesh, Najib Y. A. AL-Garadi, Ahmed I. Osman, Fahad S. Al-Mubaddel, Ahmed A. Ibrahim, Wasim U. Khan, Yousef M. Alanazi, Maher M. Alrashed, Othman Y. Alothman
Summary: Hydrogen, as an energy carrier, has the potential to replace fossil fuels and reduce environmental pollution. The accumulation of plastic waste materials poses a severe burden on the environment due to the increasing demand for plastics. Thermo-catalytic conversion of plastic waste materials to hydrogen and other fuels is a promising long-term solution to this environmental challenge, but the development of durable and high-efficiency catalysts is a potential challenge for researchers.
Article
Materials Science, Multidisciplinary
Hassam Mazhar, Douglas H. Adamson, Mamdouh A. Al-Harthi
Summary: Functionalization of hexagonal boron nitride can be achieved through oxidation and hydro-lyzation, leading to the formation of different phases of functionalized hBN. The degree of oxidation influences the dispersion properties and surface morphology of hBN.
MATERIALS CHEMISTRY AND PHYSICS
(2023)