Journal of Materials Science

Jimenez, Maude

doi: 10.1007/s10853-023-08657-3pmid: N/A

Graphical abstract[graphic not available: see fulltext]

Sharma, Aditya; Sharma, Sumit; Ajori, Shahram

doi: 10.1007/s10853-023-08672-4pmid: N/A

Phagraphene is a newly proposed two-dimensional allotrope of carbon. Its structure resembles that of a defective graphene sheet. The unit cell structure of phagraphene consists of a 5–6–7 ring sequence due to which it possesses lower energy than most carbon allotropes. Phagraphene has properties, namely thermal conductivity of 218 ± 20 W/mK and 285 ± 29 W/mK, along armchair and zigzag directions, respectively, a tensile strength of 85 ± 2 GPa, the elastic modulus of 870 ± 15 GPa along armchair and 800 ± 14 GPa along zigzag direction, and fracture strain of the same order as that of pristine graphene. Density functional theory and molecular dynamics simulations have proved the unique electronic properties of phagraphene, namely direction-dependent Dirac cones, tunable Fermi velocities, quasi-direct band gap, to be comparable with pristine graphene. Based on molecular dynamics and density functional theory investigations, phagraphene is capable of being used in Li-based batteries and thermoelectric devices as anode material due to its good adsorption properties and remarkably good doping characteristics. Such characteristics can lead to a future trend of analyzing such allotropes because phagraphene can provide potential applications in atmospheric pollutant-detecting and drug-carrying properties in ailments like cancer. This paper is a nascent one discussing all the previous works on molecular dynamics simulations of phagraphene and tries to serve as the leading one for researchers interested in this field. This paper summarizes the mechanical and thermal properties of phagraphene estimated using molecular dynamics simulations as studied in previous works. The study shows that molecular dynamics has a good application in studying such a novel carbon allotrope. The discussions made in this paper thematize phagraphene’s properties as a next-generation material and can help the researchers in a qualitative overview.

Ovalle-Encinia, Oscar; Lin, Jerry Y. S.

doi: 10.1007/s10853-023-08652-8pmid: N/A

Short porous ceramic tubes in small quantities are needed for membrane-related research and development efforts and can be synthesized by centrifugal casting (CC) or cold isostatic pressing (CIP) methods. This work evaluates the characteristics of porous ceramic tubes prepared by both methods and provides a strategy for selecting the proper method for ceramic tube fabrication, depending on its application. Samarium-doped ceria (SDC) with an average crystallite size of 10 nm was synthesized by a citrate method and used to make porous SDC tubes by the CC and CIP methods under different conditions. Porous SDC tubes were prepared from an aqueous suspension of the SDC powder with polyvinyl alcohol (PVA) using a cylindrical metallic mold, centrifugated at 4000–6000 rpm, followed by sintering in 1200–1500 °C. SDC tubes were also made by the CIP method from the SDC powder placed inside a cylindrical rubber bag followed by isostatic compression at 1379 bar. The pore structure of the SDC tubes was characterized by helium permeation and liquid nitrogen Archimedes method. Due to high compression pressure giving a low porosity green tube, the CIP method with lower sintering temperature produces SDC tubes with much lower porosity and average pore size and similar tortuosity compared to the CC methods. The CIP method should be used to prepare low porosity or dense ceramic tubes, and the CC method should be used for preparing high-porosity ceramic tubes or tubes with pore gradient tube wall.Graphical abstract[graphic not available: see fulltext]

Li, Jingjing; You, Junhua; Wang, Zhiwei; Zhao, Yao; Xu, Jingsheng; Duan, Mingyi; Zhang, Hangzhou

doi: 10.1007/s10853-023-08683-1pmid: N/A

A series of Fe2O3/BiVO4 composite photo-Fenton catalysts were prepared by a simple ultrasonic-assisted calcination method. By changing the calcination temperature, FB-2 with tetragonal structure BiVO4 has excellent photo-Fenton performance. The crystal structure and chemical composition of the composite catalyst were studied by a series of characterizations. Under 5 W LED illumination, 97% rhodamine B dye (Rh B) was degraded within 40 min in FB-2 sample, which was attributed to the high efficiency of photogenic electron–hole pair separation. The subsequent capture experiment and Tafel test proved that h+, e−, ·OH were the main active substances in the degradation process and the flow direction of electrons in the reaction process. The composite catalyst has good cyclic stability and efficient photo-Fenton catalytic degradation performance, and has good reference value for the degradation of water dyes.

Lee, Mei Bao; Lee, Chiew Tin; Chong, William Woei Fong; Wong, King Jye

doi: 10.1007/s10853-023-08685-zpmid: N/A

The inconsistent conductivity and surface roughness of commercially available chemical vapour deposition (CVD) monolayer graphene films have limited their widespread adoption in optoelectronic devices. This study presents a novel approach to address this issue by investigating the effect of post-thermal annealing on the sheet resistance (Rs) and surface properties of CVD monolayer graphene films on quartz substrates. The films undergo thermal annealing at temperatures ranging from 200 to 600∘C\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$600\,^{\circ }\hbox {C}$$\end{document} in a nitrogen environment using a one-zone tube furnace. Remarkably, annealing the graphene films at 400∘C\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$400\,^{\circ }\hbox {C}$$\end{document} leads to a remarkable reduction in Rs by 58.1% and surface roughness (Ra) by 33.3%. In-depth analysis using Raman spectroscopy reveals that the Rs reduction is attributed to increased charge density from doping effects, while the Ra reduction is attributed to thermal-induced mechanical biaxial tensile strain. Moreover, the Raman spectrum exhibits a remarkable 67.3% reduction in the quality–intensity ratio (ID\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${I}_\textrm{D}$$\end{document}/IG\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${I}_\textrm{G}$$\end{document}) of the graphene film annealed at 400∘C\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$400\,^{\circ }\hbox {C}$$\end{document}, confirming a defect-free state, and further validating the healing effect on the commercially procured graphene films. These findings offer great potential for enhancing the performance and reliability of commercially available CVD monolayer graphene films in optoelectronic devices. By introducing a practical solution to improve conductivity and surface roughness, post-thermal annealing at an optimal temperature of 400∘C\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$400\,^{\circ }\hbox {C}$$\end{document} presents a promising and innovative approach to unlock the full potential of CVD monolayer graphene films in various technological applications.

Pandey, Deepak K.; Jadav, Divya; Tsunoji, Nao; Singh, Dheeraj K.; Dharaskar, Swapnil; Bandyopadhyay, Mahuya

doi: 10.1007/s10853-023-08661-7pmid: N/A

The use of supported ionic liquid catalysts has gained popularity as they can address the limitations of conventional ionic liquids (ILs). Therefore, in this study, two supported ionic liquids (SILs) through a wet impregnation approach were developed, where 1-ethyl-3-methylimidazolium tetrafluoroborate (C2mim BF4) and 1-hexyl-3-methylimidazolium chloride (Hmim Cl) were immobilized on layered silicate material, specifically HUS-7, to produce a novel catalyst. The binding of the ILs with layered silicate HUS-7 was confirmed using various characterization techniques (XRD, FE-SEM, 1H MAS NMR, N2 isotherms), indicating strong interactions between each IL and layers of HUS-7. A detailed structural analysis of the SILs was conducted using ATR-IR spectroscopic techniques in conjunction with quantum chemical calculations. Despite the different cationic and anionic parts of the chosen ILs, almost similar activity was observed. The outcomes show a strong heterogeneous catalyst was produced as a result of ILs' interaction with layered silicate. To ascertain the robustness of each synthesized catalyst, the reusability and structural analyses of the used catalysts were also performed.Graphical abstract[graphic not available: see fulltext]

Senturk, Oguzkan; Palabiyik, Mehmet

doi: 10.1007/s10853-023-08662-6pmid: N/A

One of the major challenges in using GO or other nanofiller materials in the polymer matrix is nonhomogeneous dispersion and aggregation. In situ polymerization is promising for obtaining well-dispersed GO-filled polymer nanocomposites and imposing unique friction and wear characteristics. Thus, the tribological properties of PA6/GO nanocomposites produced by in situ polymerization were investigated in this study. To establish whether the in situ polymerization was completed successfully, characterization tests using XRD, XPS, FT-IR, Raman spectroscopy, and AFM were initially carried out. All of the characterization tests indicated convincingly that PA6 was successfully grafted onto GO flakes using in situ polymerization. Next, the thermal properties of the nanocomposites were determined by DSC, TGA and LFA. The nucleation influence of GO resulted in a higher crystallization temperature, and the GO content had a minor effect on Td. The load carrying capacity is investigated by tensile, bending, and impact tests. When compared to PA6, increasing the GO content increased the tensile, flexural, and impact properties. A significant reduction in friction coefficients is achieved with increasing GO weight fraction, and the wear rates at any sliding distance are lower than those of PA6. Furthermore, the friction heat was quickly dissipated by the higher thermal conductivity coefficient, contributing to the lower friction temperatures with increasing GO weight fraction. The PA6/GO nanocomposites formed a continuous and smooth transfer film on the steel counterfaces as the GO content increased. These observations prove the success of in situ polymerization for achieving unique friction and wear characteristics.Graphical Abstract[graphic not available: see fulltext]

Mohamed Mydeen, K; Arumugam, Hariharan; Krishnasamy, Balaji; Subramani, Devaraju; Muthukaruppan, Alagar

doi: 10.1007/s10853-023-08671-5pmid: N/A

For a broad range of purposes, including the water-repellent fabrics, low-k and anticorrosion applications, four unique series of benzoxazines based on nonylphenol were synthesized and utilized. Different mono and diamines were used for making variety of nonylphenol-based benzoxazines. The chemical structure of benzoxazines was determined by spectroscopic methods. The characteristic properties related to thermal studies of benzoxazines have been evaluated using TGA and DSC. Among the benzoxazines investigated, poly(NP-oda) had an excellent water-repellent nature than the other benzoxazines studied. NP-oda-coated cotton fabrics have water contact angle (WCA) value of 162°, indicating superhydrophobic behavior. Poly(NP-ffa) and poly(NP-ddm) had char residue values of 29% and 30%, respectively, greater than rest of the polybenzoxazines. Dielectric (k) studies of BG-silica incorporated poly(NP-ffa) composites made from Bermuda grass provide the k value 1.76 (ultra-low-k) with loss factor 0.0029. Similarly, the composites made of 5 wt% of SBA-15 incorporated poly(NP-ddm) lower the k value to 1.69 with loss value of 0.0082. Furthermore, benzoxazine with inbuilt catalytic amines exhibits superior corrosion resistance on mild steel specimen surfaces. Data from several investigations suggested that nonylphenol-based benzoxazine and composites can be employed as useful materials for applications such as corrosion resistance, water repellency and microelectronic insulation.Graphical Abstract[graphic not available: see fulltext]

Liu, Shujuan; Liu, Lijuan; Yang, Kangli; Yuan, Zhiqing; Li, Xinyi; Li, Cancheng; Meng, Shoutong

doi: 10.1007/s10853-023-08682-2pmid: N/A

In order to improve the environmental problems caused by the extensive use of plastics, this paper introduced a new strategy to add and modify the physical structure, which could not only reduce the use of plastics, but also improve the mechanical properties of bamboo plastic composites. In this work, the bamboo-woven structure was introduced into the bamboo fiber/low density polyethylene (LDPE) composites to enhance the mechanical properties. Besides, to enhance the interfacial compatibility, maleic anhydride (MA) and polyvinyl alcohol (PVA) were used to modify LDPE and bamboo-woven structure, respectively. The mechanical properties of the prepared PVA-bamboo-woven structure/bamboo fiber/MA-LDPE composites were greatly improved. The bamboo plastic composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, water contact angle (WCA) test and mechanical property test. The results showed that the bamboo-woven structure/bamboo fiber/MA-LDPE composite has superior properties at 45% bamboo fiber content. The tensile strength reached to 33.842 MPa, which was increased by 65.01% compared to the bamboo fiber/MA-LDPE composites, and the bending strength reached to 36.6585 MPa increased by 81.46% in relation to the bamboo fiber/MA-LDPE composites. In addition, even a large number of hydrophilic bamboo fibers and bamboo-woven structure were carried by the composites, a good hydrophobicity was still maintained and the WCA reached to 93.71°. The composites with excellent mechanical properties and hydrophobicity provided a reference for the use of bamboo fibers in environmentally friendly packaging materials.

González-Castillo, Eduin I.; Torres, Yadir; González, Francisco J.; Aguilar-Rabiela, Arturo E.; Shuttleworth, Peter S.; Ellis, Gary J.; Boccaccini, Aldo R.

doi: 10.1007/s10853-023-08686-ypmid: N/A

The thermal stability and degradation, near-to-surface mechanical properties, and scratch resistance and damage mechanism of poly(etheretherketone) (PEEK)/reduced graphene oxide (RGO) nanocomposite coatings are analyzed and discussed in terms of their nanosheet content and microstructure. Although RGO modified the thermal stability and degradation of the polymeric matrix, for instance, by slightly reducing the onset degradation temperature, its addition was not a limiting factor in the PEEK processing. Respecting the microstructural features induced by the nanosheets, the nanocomposite coatings were found to exhibit (i) a partially exfoliated and large-scale co-continuous morphology related to RGO nanosheets whose basal planes were mainly aligned with the coating surface, (ii) a dendritic morphology of PEEK domains related to transcrystallinity, (iii) and irregular domains associated with the deposition of PEEK particles wrapped by the nanosheets. The changes provoked by RGO in the morphology and PEEK crystalline phase influenced the near-to-surface mechanical properties, scratch resistance, and scratch damage mechanism of the nanocomposite coatings. Within this context, the interlayer strength between the nanosheets in the large-scale co-continuous morphology and PEEK transcrystallinity had an important effect. Furthermore, the random-bumpy surface texture formed by the irregular PEEK domains together with the conformal cracking damage mechanism was decisive in the scratch response of the PEEK/RGO nanocomposite coatings. The comprehensive characterization carried out in this work concludes that PEEK/RGO electrophoretic coatings are suitable for a variety of applications requiring tribo-mechanical resistance.Graphical Abstract[graphic not available: see fulltext]