Article
Polymer Science
Konstantin A. A. Milakin, Oumayma Taboubi, Udit Acharya, Miloslav Lhotka, Vaclav Pokorny, Magdalena Konefal, Olga Kockova, Jirina Hromadkova, Jiri Hodan, Patrycja Bober
Summary: Magnetic polypyrrole-gelatin-barium ferrite (PPy-G-BaFe) cryogels/aerogels were successfully synthesized by incorporating barium ferrite nanoparticles into a gelatin solution and conducting one-step oxidative cryopolymerization of pyrrole. The resulting aerogels exhibited higher specific surface area and conductivity compared to PPy-G aerogel prepared without barium ferrite. The magnetic PPy-G-BaFe aerogel with 10 wt% BaFe content showed significantly improved adsorption capacity and rate for anionic dye removal, making it an attractive adsorbent for water purification.
Article
Chemistry, Inorganic & Nuclear
Salma Aman, H. I. Elsaeedy, F. F. Alharbi, Syeda Rabia Ejaz, Naseeb Ahmad, Muhammad Zeshan, Mahmood Ali, HafizMuhammad Tahir Farid
Summary: Nanocomposites consisting of BaFe2O4 and polypyrrole were prepared using the sol-gel method, and the addition of spinel ferrite was found to increase the crystallite size of the composite. The results showed that the addition of ferrites decreased the dielectric constant and dielectric loss as a function of frequency, while increasing the DC resistivity and activation energy. The magnetic properties of the nanocomposites, including coercivity, remanence magnetization, and saturation magnetization, all showed an increase with the ferrite content.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Review
Materials Science, Textiles
Yunfan Long, Yongjun Deng
Summary: Carbon fiber paper (CP) was prepared using wet forming technology, and liquid-phase polypyrrole/carbon fiber paper matrix composites (LPPY/CF) and gas-phase polypyrrole/carbon fiber paper matrix composites (GPPY/CF) were prepared by liquid-phase polymerization and gas-phase polymerization on CP, respectively. The effects of dopant, oxidant, solubility of pyrrole (PY) and ferric trichloride (FeCl3) on the resistivity of LPPY/CF and GPPY/CF were discussed. The mechanical properties, hydrophobicity, electrical conductivity, and heating properties of CP, LPPY/CF, and GPPY/CF were compared. The results showed significant improvements in resistivity, mechanical properties, hydrophobicity, electrical conductivity, and heating properties in LPPY/CF and GPPY/CF compared to CP.
FIBERS AND POLYMERS
(2023)
Article
Chemistry, Physical
Chao Feng, Jiaxing Huang, Peihui Yan, Fei Wan, Yunfei Zhu, Hao Cheng
Summary: The research on the application of polypyrrole materials in cement composites shows that adding waterborne polypyrrole can improve conductivity and compactness, optimize microstructure, and inhibit the formation of Ca(OH)2.
Article
Chemistry, Physical
Zihao Chen, Dawei Mu, Tianhao Liu, Zilong He, Yi Zhang, Huaming Yang, Jing Ouyang
Summary: A three-phase PANI/BaFe12O19@Hal heterostructure was designed and fabricated in this study as an efficient lightweight electromagnetic wave absorbing material. The material exhibited the best microwave absorption performance when the weight ratio of PANI was 40%, with a frequency bandwidth of 9.60 GHz and a minimum absorption peak of 14.77 dB at 11.92 GHz. Introducing halloysite improved the microwave absorption performance and enriched the absorbing mechanism of the composite materials.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Engineering, Environmental
Perumal Karthikeyan, S. Sd Elanchezhiyan, Sankaran Meenakshi, Chang Min Park
Summary: The novel MgFe2O4-reinforced polypyrrole hybrids show promising capabilities in removing PO4-, NO3-, and Cr(VI) from water, with high adsorption efficiency and good regenerability.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Dawei Mu, Zihao Chen, Tianhao Liu, Zilong He, Yi Zhang, Huaming Yang, Xiaochao Zuo, Jing Ouyang
Summary: A barium ferrite/amorphous carbon nanotubes composite was synthesized via solvothermal method after preparing ACNTs using halloysite as the template. The composite exhibited hexagonal BaF nanosheets surrounded by partially graphitized ACNTs, showing the best microwave absorption performance at a weight ratio of 40/60. The unique microstructure of the composite material led to multiple reflections of electromagnetic waves and promoted the loss of electromagnetic energy, suggesting potential applications in electromagnetic attenuation materials.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Yue-Yi Wang, Song-Yang, Wen-Jin Sun, Kun Dai, Ding-Xiang Yan, Zhong-Ming Li
Summary: Barium ferrite (BaFe12O19) is a potential microwave absorption material, but the performance is limited by the poor dispersion of carbon nanotubes (CNTs) in the composites prepared by ball-milling method. In this study, CNTs were uniformly introduced into the precursor of BaFe12O19 during the auto-ignition process and calcined under different atmospheres. The resulting CNT/BaFe12O19 composites exhibited significantly improved microwave absorption performance compared to pure BaFe12O19 and CNT/BaFe12O19 composites prepared by ball-milling method.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Xinyang Wang, Bo Wang, Shicheng Wei, Yi Liang, Yujiang Wang, Linwei Li, Zhen Liu
Summary: The magnetic-dielectric composite with a metal-organic framework (MOF) structure has shown great potential for effective microwave absorption. By utilizing the sol-gel method, h-MWCNT/doped barium ferrite composites were prepared with a porous MOF structure that had abundant microscopic cavity structure and an adequate conductive network. The optimized composition of h-MWCNTs achieved a minimum reflection loss of -56.47 dB at 4.8 GHz and a maximum wave-absorbing bandwidth of 6.20 GHz, covering the Ku band.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Polymer Science
Rizwan Ullah, Nadia Khan, Rozina Khattak, Mehtab Khan, Muhammad Sufaid Khan, Omar M. Ali
Summary: The current research focused on the super capacitive behavior of organic conducting polymer, i.e., polypyrrole (PPy) and its composites with gum arabic (GA). The synthesized composites material showed high thermal stability and compact morphology. The electrochemical properties of the composites exhibited impressive specific capacitance and high energy density.
Article
Materials Science, Multidisciplinary
Tyler Haussener, Niknam Momenzadeh, Paris von Lockette
Summary: MAEs, subclass of smart materials, show improved actuation and magnetic work when higher net magnetic remanence is achieved through a process of creating particle alignment in a strong external magnetic field. The study focused on investigating the effects of varying volume content of magnetic material, particularly on physical particle alignment and bulk magnetic properties. Results indicated that as volume fraction of magnetic filler increased, both physical particle orientation and net magnetic properties per volume remained fairly constant, with a local minimum in physical particle orientation at medium volume fractions.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Chemistry, Physical
A. Plyushch, D. Lewin, A. Sokal, R. Grigalaitis, V. V. Shvartsman, J. Macutkevic, S. Salamon, H. Wende, K. N. Lapko, P. P. Kuzhir, D. C. Lupascu, J. Banys
Summary: Bulk BaTiO3-xCoFe2O4 (x = 0.1 - 0.6) magnetoelectric composites with high purity and excellent dielectric and magnetic properties were prepared using the phosphate bonded ceramics approach. The dielectric properties were influenced by composition-dependent relaxations and anomalies at different frequencies, while the magnetic properties were limited by the size of CoFe2O4 particles. The measured direct magnetoelectric coupling coefficient was higher than that of conventionally sintered ceramics and comparable to that of core-shell structures.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
D. Padmapriya, D. Dhayanithi, M. T. Rahul, Nandakumar Kalarikkal, N. Giridharan
Summary: This article systematically studied room-temperature magnetoelectric coupling in 0-3 particulate and 2-2 laminated composite structures, showing significant variations in electrical polarization and magnetization parameters in composite samples compared to pristine BTO and NFO. The perceived strain-mediated magnetoelectric coupling is strongly dependent on the relative mass ratio of BTO and NFO in both the particulate and laminated structures. An enhanced magnetoelectric coefficient of 25.23 mV/cm.Oe was achieved for the sandwiched-laminated structure of (1-x)BaTiO3 and (x)NiFe2O4 with x=0.45 at an applied magnetic field of 1.34 KOe.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Energy & Fuels
Meryem Samanci, Elif Das, Ayse Bayrakceken Yurtcan
Summary: In this study, carbon aerogels with different structural properties were synthesized and their polypyrrole composites were prepared. The change in capacitive properties with the addition of PPy to carbon aerogel was determined. It was observed that the addition of PPy significantly increased the specific capacitance of the composite materials.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Electrochemistry
Saira Ishaq, Mahmoud Moussa, Farah Kanwal, Raheel Ayub, Truc Ngo Van, Umar Azhar, Dusan Losic
Summary: The aim of the study was to fabricate high-energy density supercapacitor electrodes. Binary composite of rGO/CoFe2O4 and ternary composite of rGO/CoFe2O4/PPy were synthesized to improve the capacitance and energy density of the supercapacitors. The results showed a simple fabrication method of binary and ternary nanocomposites and the synergistic influence of participating components on electrode performance for high gravimetric and areal capacitances, as well as high energy and power densities.
ELECTROCHIMICA ACTA
(2022)
Article
Physics, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: The quarter-wavelength model suggests that the reflection of microwaves can be minimized by adjusting the film thickness to m lambda/4, where m is an odd integer and lambda is the wavelength within the film. However, this study challenges the validity of the model and proposes an alternative approach based on wave superposition principles. The study also criticizes the inappropriate use of certain concepts in current mainstream microwave absorption theory, such as the characterization of microwave absorption using reflection loss RL from materials.
Article
Thermodynamics
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: The study of the Gibbs-Duhem equation and its applications is one of the most difficult topics in thermodynamics. This paper presents a novel mathematical derivation that is shown to be more natural, direct, and intuitive than the traditional thermodynamic derivation. By introducing Legendre transformations, multiple perspectives for problem-solving are provided.
INTERNATIONAL JOURNAL OF THERMOPHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: For many years, it has been common practice to use reflection loss defined for devices to characterize materials, which has caused many problems. By replacing the flawed theory of impedance matching with wave superposition theory and using simple geometry to represent film absorption, the real mechanism of film absorption has been revealed. It is shown that film and material are different, and absorption efficiency is influenced by factors such as wave superposition and energy conservation.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ying Liu, Yue Liu, Michael G. B. Drew
Summary: This section discusses the application of impedance matching and quarter-wavelength theories in microwave absorption research, pointing out their flaws and proposing a new theory to replace the quarter-wavelength theory.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Jiahe Song, Kun Zhao, Xiangbin Yin, Ying Liu, Iltaf Khan, Shu-Yuan Liu
Summary: A Z-scheme g-C3N4/Ag/AgBr heterojunction photocatalyst was prepared via in-situ loading through photoreduction method. The g-C3N4/Ag/AgBr composite showed excellent photocatalytic performance in the degradation of tetracycline hydrochloride pollutants. The main active oxygen species involved in the degradation of organic pollutants were O2^- and (OH)·.
FRONTIERS IN CHEMISTRY
(2022)
Article
Physics, Applied
Ying Liu, Michael G. B. Drew, Yue Liu
Summary: In the previous Part I, it was demonstrated using transmission-line theory that impedance matching theory should be replaced by wave cancellation theory. It was also shown that film is different from the material and phase effects from interfaces should be considered in quarter wavelength theory. In this Part, it is proven that energy penetration in a film cannot be defined and impedance matching is flawed as it lacks theoretical proof and consistency with experimental data. The multiple absorption peaks in a film arise from wave cancellation under the constraint of energy conservation, rather than resonances from the material.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Ying Liu, Michael G. B. Drew, Yue Liu
Summary: This study theoretically confirms that the absorption mechanism in a film, responsible for the minima of the reflection loss (RL/dB), is best explained by wave cancelation theory rather than by impedance matching theory. The study also reveals that the mechanisms for a film and material are different. In addition, the flaws of neglecting the phase effects of interfaces in a film in quarter-wavelength theory are quantitatively discussed.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Condensed Matter
Ying Liu, Xiangbin Yin, Michael G. B. Drew, Yue Liu
Summary: By analyzing experimental data, this study provides new theoretical perspectives on the inadequacies of impedance matching theory in the field of microwave absorption. It suggests that the current theories related to impedance matching need to be replaced by wave cancellation theory, as even different criteria cannot solve the problems with impedance matching. The analysis in this work supports the new theories against the current ones by applying to published data and determining the conditions for the minima of reflection loss at large values of |Zin - Z0| through transmission-line theory.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Ying Liu, Yi Ding, Yue Liu, Michael G. B. Drew
Summary: It is commonly believed that two synergistic effects maximize microwave absorption power of a film - increasing the absorption power of the material and the penetration of incident microwaves into the film. However, this reasoning is incorrect as it confuses material with film and is not consistent with the real absorption mechanism. By differentiating film from material, it is shown that reflection loss (RL) is relevant only for film and the real mechanism involves balancing the intensities of the two beams reflected from the film's interfaces when they are out of phase by π. It is commonly believed incorrectly that maximum absorption from film occurs when the resultant beam reflected back to open space from the metal-back interface is weakest. But it is shown here that the opposite is true - maximum absorption occurs when this reflected beam reaches its maximum. A definition for film in the context of microwave absorption is proposed.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Physical
Ying Liu, Yi Ding, Yue Liu, Michael G. B. Drew
Summary: Part 1 of this work demonstrates that film absorption is based on wave cancellation theory (WCT) rather than the mechanism of material attenuation power and impedance matching theory (IM). The film thickness and material properties affect the pattern of the reflection loss curve and the occurrence of multiple absorption peaks. Maximum absorption occurs when the two reflected beams are out of phase by & pi; at the front of the film, regardless of whether the film has a metal back or not. WCT explains the deviations of maximum absorption positions from the predicted values of IM.
SURFACES AND INTERFACES
(2023)