Article
Thermodynamics
Abdul G. Al Lafi, Ghina Alsayes
Summary: The article introduces the application of two-dimensional correlation mapping (2D-CM) technique in analyzing DSC curves of poly (ether ether ketone) (PEEK) samples, which helps to extract relevant information to explain the double melting behavior of PEEK.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Materials Science, Characterization & Testing
Sen Niu, Xiaoxue Bai, Yimu Cheng, Hao Qin, Yunhe Zhang, Zhenhua Jiang
Summary: A series of PEEK-based blends with self-crosslinkable c-PEI were prepared by melt blending as high temperature dielectrics. The obtained polymer blends exhibited stable dielectric properties over a wide frequency and temperature range. The crosslinked networks in the blends efficiently restricted the movement of polymer segments, leading to suppressed dielectric loss and enhanced high temperature performance.
Article
Engineering, Chemical
Mamta Kumari, John C. Douglin, Dario R. Dekel
Summary: A series of mechanically robust and highly conducting crosslinked anion-exchange membranes were synthesized using quaternary phosphonium-functionalized poly(ether ether ketone) (QPPEEK) as the base polymer and poly(ethylene glycol) (PEG) as the crosslinker. Among different compositions, the QPPEEK-PEG 20 membrane showed the best properties with high hydroxide conductivity, good mechanical strength, and flexibility. This crosslinked membrane was chemically stable in alkaline environment and performed well in anion-exchange membrane fuel cell applications, indicating the potential of PEEK-based membranes for such applications.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Polymer Science
Chris Croshaw, Levi Hamernik, Lina Ghanbari, Andrea Browning, Jeffrey Wiggins
Summary: This study investigates the thermal degradation mechanism of poly(ether ketone ketone) (PEKK) in the melt-state in air using molecular dynamics simulations, X-ray photoelectron spectroscopy, and rheology. The study reveals that the ether linkages in the PEKK backbone have the lowest bond dissociation energies and preferentially undergo chain scission. The rheological properties of PEKK are highly influenced by exposure time in the melt-state and angular frequency.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Chemistry, Physical
Alphonse Haragirimana, Na Li, Zhaoxia Hu, Shouwen Chen
Summary: This study investigates the effect of thermal crosslinking on SPEEK/SPAES membranes, showing that the thermally-crosslinked membranes exhibit excellent physicochemical and electrochemical performance, indicating potential applications in fuel cells.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Polymer Science
E. Pajuste, I Reinholds, G. Vaivars, A. Antuzevics, L. Avotina, E. Sprugis, R. Mikko, K. Heikki, R. M. Meri, R. Kaparkalejs
Summary: This study evaluates the effects of electron beam irradiation on two types of proton exchange membranes (PEM) and finds that sulfonated poly(ether-ether-ketone) (SPEEK) exhibits higher mechanical and thermal stability after irradiation, making it a promising replacement for traditional PEM in fuel cell applications exposed to ionizing radiation.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Nanoscience & Nanotechnology
Yuhan Liu, Zijian Zhang, Xinwei Du, Yuliang Wang, Xiaohui Guo, Mengxuan Yu, Baijun Liu, Wei Hu, Li Shen, Yunfeng Lu, Guangshan Zhu
Summary: The traditional polyolefin separators used in lithium-ion batteries have limitations such as poor wetting of electrolytes and insufficient thermal stability. To overcome these limitations, a modified phase inversion technique was developed to coat polyolefin separators with poly(ether ether ketone) (PEEK) efficiently and durably. The PEEK-coated polyolefin separators exhibit comparable mechanical properties with unmodified separators, as well as outstanding thermal stability and enhanced ionic conductivity, leading to significant improvement in the electrochemical performance of prototype half cells. This modified technique provides a practical solution for next-generation separator materials.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Polymer Science
Sachin S. Kuhire, Aniket A. Talanikar, Bhausaheb Tawade, Samadhan S. Nagane, Prakash P. Wadgaonkar
Summary: A new series of partially bio-based (co)poly(ether ether ketone)s with pendent furyl groups was successfully synthesized. These polymers exhibited high molecular weights and good solubility, allowing them to form tough, transparent, and flexible films with high glass transition temperatures and maintained stable mechanical properties during recycling. The study also demonstrated the Diels-Alder/retro Diels-Alder reactions of the polymers through various analyses.
POLYMER INTERNATIONAL
(2021)
Article
Engineering, Chemical
Hu-Geun Kwon, Insung Bae, Seong-Ho Choi
Summary: Crosslinked poly(arylene ether ketone) membranes were synthesized for use in non-aqueous redox flow batteries, resulting in improved cell efficiency.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Polymer Science
Akanksha Patel, Varun Venoor, FeiFei Yang, Xu Chen, Margaret J. Sobkowicz
Summary: PEEK is increasingly used in SLS due to its superior properties, and research shows that thermal treatment results in increased crystallinity, unchanged particle size and shape, increased melt viscosity, and slightly improved flowability. Understanding these changes could help reduce waste.
POLYMER DEGRADATION AND STABILITY
(2021)
Article
Chemistry, Physical
Ziyue Zhao, Jindong Zhang, Ran Bi, Chunhai Chen, Jianan Yao, Gang Liu
Summary: This study used PAEK resin with a low melting temperature to prepare laminate for CCF-PAEK composites, followed by injection of high melting temperature PEEK or SCF-PEEK for overmolding. The interface properties of the composites were affected by the interface temperature, which was adjusted by mold temperature. Higher interface temperatures resulted in better interfacial bonding between PAEK and PEEK. The melting temperature did not significantly affect the shear strength of SCF-PEEK/CCF-PAEK short beams.
Article
Polymer Science
A. D. Drozdov, J. DeClaville Christiansen
Summary: Observations are reported on PEEK in uniaxial tensile tests, relaxation tests and creep tests at temperatures ranging from room temperature to 180 degrees C. Constitutive equations are developed for PEEK's thermo-mechanical behavior under uniaxial deformation, with adjustable parameters found by matching experimental data. Good agreement is shown between observations and results of numerical simulation, indicating similar activation energies for various responses at temperatures above the glass transition point.
Article
Engineering, Biomedical
Shuai Li, Tianyu Wang, Jiqiang Hu, Zhibin Li, Bing Wang, Lianchao Wang, Zhengong Zhou
Summary: A novel surface porous PEEK (SP-PEEK) was successfully fabricated through fused deposition modelling three-dimensional printing (FDM 3DP), allowing for adjustment of pore diameter and layer number to mimic human bones and improve osseointegration.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Article
Materials Science, Characterization & Testing
Fei Yu, Linghan Xiao
Summary: The addition of poly(ether sulfone) modified graphene reduced the crystallinity of PEEK composites and shortened the total crystallization time. With increasing the mass ratio of PES to GE, the peak temperature and nucleation activity of f-GE(i) increased before declining.
Article
Polymer Science
Xiaoran Yang, Seiya Yokokura, Taro Nagahama, Makoto Yamaguchi, Toshihiro Shimada
Summary: This study uses molecular dynamics and a new approximation method to simulate local vibrational features and investigate the effect of intermolecular ordering on Raman spectra. The results show that intermolecular ordering does impact low wavenumber Raman spectra and X-ray diffraction.
Article
Chemistry, Physical
Abdul G. Al Lafi, James N. Hay
JOURNAL OF MOLECULAR STRUCTURE
(2019)
Article
Polymer Science
Abdul G. Al Lafi, Bassem Assfour, Thaer Assaad
JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
(2020)
Article
Polymer Science
Abdul G. Al Lafi, Reem Hasan, Nedal Al-Kafri
MACROMOLECULAR RESEARCH
(2019)
Article
Spectroscopy
Abdul G. Al Lafi, Mohamed Salah Rihawy
X-RAY SPECTROMETRY
(2020)
Article
Spectroscopy
Abdul G. Al Lafi, Mohammed S. Rihawy
Summary: The study suggests the use of 2D-CM methods to analyze PIXE and RBS spectra, revealing the chemistry involved in different ion irradiation types and the impact of sulfonation on PEEK membrane structures. The techniques are promising in enriching information obtained from ion beam analysis.
X-RAY SPECTROMETRY
(2021)
Article
Materials Science, Multidisciplinary
Abdul G. Al Lafi, Bassem Assfour, Thaer Assaad
Summary: This study investigates the processing of MOF-type material MIL-101(Cr) through gamma-ray irradiation at low doses, determining 15 kGy as the optimal dose for increasing iodine adsorption by more than 40%. Results show significant particle agglomeration post-irradiation, while preserving the unit cell topology and mesoporous structure of the MOF.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Abdul G. Al Lafi, Jamal Al Abdullah, Yusr Amin, G. Alsayes, Nedal Al-Kafri
Summary: Loading NMO onto the surface of polymers changes the pH PZC of the composite, affecting its structural and morphological properties. Spectroscopic analysis tools are powerful in determining the pH PZC and studying structural changes in solid materials.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Multidisciplinary Sciences
Abdul G. Al Lafi, Ali Alzier, Abdul W. Allaf
Summary: Proton irradiation of PEEK films led to different extents of crystallization, which were characterized using wide angle X-ray diffraction and 2D correlation mapping (2D-CM). The study showed that proton irradiation favored the formation of crystal form II and altered the orientation within the films. Differential scanning calorimetry and Raman spectroscopic analysis confirmed these effects.
Article
Polymer Science
Abdul Ghaffar Al Lafi, Mohammed Amer Mougrabya, Osama Shehada
Summary: This present work focuses on using two-dimensional correlation spectroscopy (2D-COS) to analyze X-ray photoelectron spectroscopic (XPS) data, and to obtain qualitative information about the underlying physics and chemistry of the studied process. The effects of the probing incident X-ray beam on the measured samples are also explored.
JOURNAL OF POLYMER RESEARCH
(2022)
Article
Spectroscopy
Abdul G. Al Lafi, Jamal Al Abdullah, Yusr Amin, Yara Aljbai, Hussam Allham, Asmhan Obiad
Summary: Fourier Transform Infra-Red (FTIR) spectroscopy is an important technique for understanding the structure of adsorbents and designing improved ion exchange materials. This study investigates the adsorption mechanism of U(VI)/Th(IV) and Ra(II)/Ba(II) radionuclide couples on polystyrene nano manganese dioxide (PS-NMO) composite, focusing on the effect of working solution pH. The results show that the separation of U(VI)/Th(IV) and Ra(II)/Ba(II) couples can be effectively achieved at specific pH values, and the pH also affects the structure of the composite adsorbent. FTIR spectroscopy reveals the formation of different complexes and changes in the composite structure in response to metal ions.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Polymer Science
Abdul Ghaffar Al Lafi, Atef Arfan, Dalal Alnaama, Reem Hasan, Mazen Ibrahim, Ghina Alssayes
Summary: Sulfonated poly(ether ether ketone) (SPEEK) is a high-performance and low-cost polymer electrolyte membrane that has been widely studied as a potential replacement for Nafion membranes in fuel cells and redox flow batteries. This research investigated the effects of different membrane treatments on SPEEK membranes and successfully achieved cross-linking without affecting the degree of sulfonation. The study also found solid-state sulfonation and the formation of ether links between polymer chains. It is recommended to use high degree of sulfonation membranes for harsh environment applications.
JOURNAL OF POLYMER RESEARCH
(2022)
Article
Chemistry, Applied
Abdul Ghaffar Al-Lafi, Isam AL-Naser
Summary: In this study, 2D-COS was used to analyze FTIR spectra of milk powder with different concentrations of melamine. By sequential analysis, the appropriate FTIR band for quantitative analysis was determined.
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
(2022)
Article
Polymer Science
Abdul Ghaffar Al Lafi, Atef Arfan, Dalal Alnaama, Reem Hasan, Thnaa Allaf, Mazen Ibrahim, Ghina Alssayes
Summary: This study provides spectroscopic evidence for the attachment of a second sulfone group on the para position rather than the meta position with respect to the first sulfone group in the sulfonation of poly(ether ether ketone) (PEEK).
JOURNAL OF POLYMER RESEARCH
(2022)
Article
Polymer Science
Abdul Ghaffar Al Lafi, Hiba Dada, Hamdi Harmalani
Summary: This study investigated the effects of γ-rays irradiation and thermal treatments on expired PSF dialysis membranes (Helixone) in order to reuse them. Irradiation below 35 kGy or thermal treatments below 150 degrees C had no effect on the essential characteristics of the membranes. However, chemical and morphological changes started to appear at a dose of 35 kGy and a treatment temperature above 150 degrees C. The deterioration of membrane properties could be attributed to oxidation of the polymer in irradiation treatment and degradation and elution of polyvinylpyrrolidone (PVP) in thermal treatments. Reactive treatments involving reloading PVP and treatment in buffer solution at pH = 7.2 for 12 h were suggested to reactivate expired Helixone membranes, reducing PVP elution by 10%.
MACROMOLECULAR RESEARCH
(2023)
Article
Thermodynamics
Abdul G. Al Lafi, Ghina Alsayes
Summary: The article introduces the application of two-dimensional correlation mapping (2D-CM) technique in analyzing DSC curves of poly (ether ether ketone) (PEEK) samples, which helps to extract relevant information to explain the double melting behavior of PEEK.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Polymer Science
Tetsu Sato, Mariko Takahashi, Takeshi Saito, Masahito Toyonaga, Itsuo Tanuma, Rie Yamada, Satoru Hosoda
Summary: An automatic evaluation system for photooxidation has been developed and successfully applied to assess the photo-OIT of LDPE samples containing photooxidation stabilizers. The system allows independent setting of various measurement conditions and provides detailed information on the photooxidation process.
POLYMER DEGRADATION AND STABILITY
(2024)
Article
Polymer Science
Zongzheng Zuo, Shuxue Zhou
Summary: In this study, three fluoroalkyl trimethoxysilane (FATMS) additives with different chain lengths were incorporated into a two-component polyurethane clearcoat to improve its hydrophobic durability. The coatings modified with FATMS maintained their surface hydrophobicity under various conditions, but quickly lost it when exposed to both UV irradiation and/or high temperature with water. The results suggest that the FATMS route is more suitable for indoor applications at room temperature.
POLYMER DEGRADATION AND STABILITY
(2024)
Article
Polymer Science
Song Li, Feng Zhao, Xueya Wang, Zhihua Liu, Jingze Guo, Yutong Li, Shuangmei Tan, Zhenxiang Xin, Shuai Zhao, Lin Li
Summary: Green flame retardants have garnered attention for their environmental friendliness, but current options fall short in achieving high flame retardancy for flammable polymers and maintaining environmental protection. This study takes a two-pronged approach to address flame retardants and the flame-retardant process. An eco-friendly bio-based synergistic flame retardant (PAU), synthesized using phytic acid (PA) and urea (U), is used to create a flame retardant coating that can be directly applied to any surface shape using polydopamine as an adhesive. The resulting EPS-PAU exhibits excellent flame retardancy, smoke suppression, and light weight while only slightly increasing the density.
POLYMER DEGRADATION AND STABILITY
(2024)
