RSC Advances

Mohamed, Nourhan; Allam, Nageh K.

doi: 10.1039/d0ra03314fpmid: 35516646

The Li-ion battery (LIB) industry has rapidly developed and dominates the market of electric vehicles and portable electronic devices. Special attention is devoted to achieving higher power and energy densities, along with enhancing safety and reducing cost. Therefore, critical insights should be made on the understanding of the behavior of the components of LIBs under working conditions in order to direct future research and development. The present review discusses the literature on the properties and limitations of different cathode materials for LIBs, including layered transition metal oxides, spinels, and polyanionic positive electrode materials, with critical insights on the structural, thermal, and electrochemical changes that take place during cycling. Besides, the strategies and techniques capable of overcoming current limitations are highlighted.

Chee, Siew Sand; Jawaid, Mohammad; Alothman, Othman Y.; Yahaya, Ridwan

doi: 10.1039/d0ra02126apmid: 35516649

In this study, three types of nanoclay [halloysite nanotube (HNT), montmorillonite (MMT) and organically modified MMT (OMMT)] were incorporated into bamboo/kenaf (B/K) reinforced epoxy hybrid composites to compare their thermo-oxidative (TOD) stability and flammability properties. B/K (50 : 50) hybrid nanocomposites were fabricated by adding 1% loading (by weight) nanoclay through a hand lay-up technique. Wide angle X-ray scattering (WAXS) and field emission scanning electron microscopy (FESEM) were used to study the morphology of the nanoclay–epoxy mixture. The TOD stability of the hybrid nanocomposites was studied with a thermogravimetry analyzer (TGA) under oxygen atmosphere. The flammability properties were evaluated using the Underwriters Laboratories 94 horizontal burning test (UL-94HB), limiting oxygen index (LOI), cone calorimetry and smoke density test. The morphological study reveals that MMT/epoxy and HNT/epoxy are highly agglomerated while OMMT/epoxy reveals a more uniform distribution morphology. The obtained results reveal that B/K/HNT shows better TOD stability below 300 °C, but B/K/MMT and B/K/OMMT show high residue content and decomposition temperatures above 300 °C. The flame retardancy of the hybrid nanocomposites improved with the loading of all types of nanoclay, but B/K/OMMT shows higher flame retardancy than B/K/MMT and B/K/HNT hybrid nanocomposites. Hybrid nanocomposites show improvement in flame properties in terms of peak heat release rate (pHRR), total heat release, fire growth rate index (FIGRA) and maximum average rate of heat emission (MARHE) and smoke growth rate index (SMOGRA) indicators. The findings from this work can be utilized to prepare high-performance fire retardant natural fiber reinforced epoxy hybrid composites for automotive and construction applications to save human lives.

Ji, Anqi; Zhang, Shuyang; Bhagia, Samarthya; Yoo, Chang Geun; Ragauskas, Arthur J.

doi: 10.1039/d0ra03620jpmid: 35516598

Three-dimensional (3D) printing is an additive manufacturing technique with a wide range of 3D structure fabrication and minimal waste generation. Recently, lignocellulosic biomass and its derivatives have been used in 3D printing due to their renewable nature and sustainability. This review provides a summary of the development of different types of biomass and its components such as cellulose and lignin in 3D printing, brief data analysis and introduction to characterization methods of the 3D printed composites. Mechanical properties such as tensile properties, Izod impact properties, and flexural properties, thermal properties and morphological properties of 3D-printed composites are discussed. In addition, other available characterization methods of 3D-printed composites are reported. The future direction of biomass and its derivatives in the field of 3D printing is also discussed.

Ben Yahia, Manel; Ben Yahia, Mohamed

doi: 10.1039/d0ra03077epmid: 35516596

In this research paper, the equilibrium isotherms for the adsorption of cobalt(ii)nitrate and cobalt(ii)chloride on tetrakis(4-tolylphenyl)porphyrin (H2TTPP) were obtained at four temperatures for modeling analysis. The experimental data describing the adsorbed quantity of cobalt particles were measured using the quartz crystal microbalance (QCM) strategy. Then, statistical physics formalism was employed to interpret the complexation mechanism by applying the real gas law that contemplates the interaction between the adsorbate particles in the free state. Advanced models treated with the law of van der Waals were applied for the single and L.B.L adsorptions of Co2+ at various temperatures (288–318 K). The experimental adsorption data of CoCl2 on porphyrins were satisfactorily fitted with the monolayer equation, showing that the chlorine particles had no effect on the complexation system, while the nitrate particles were involved in the adsorption of Co(NO3)2 and contributed to the layer formation. The physicochemical parameters of statistical physics models were estimated and used to compare the complexation mechanisms of both adsorbates. The study of the cohesion pressure (a) and the co-volume (b) confirmed that cobalt chloride guaranteed more stability during the formation of the vitamin B12 nucleus. Deeper energetic analysis demonstrated that cobalt ions were complexed by ionic or covalent bonds in the case of cobalt chloride (complexation energy (–E1/2) varies from −48.2 to −50.3), while a physisorption process took place in the case of cobalt nitrate ((–E1) varies from −33.6 to −36.1), thus indicating that CoCl2–H2TTPP was the most stable complex. The statistical physics models were also used to investigate two thermodynamic functions that govern the adsorption mechanisms, namely, the configurational entropy and the Gibbs free enthalpy.

Bosca, Federica; Corazzari, Ingrid; Foglietta, Federica; Canaparo, Roberto; Durando, Gianni; Pastero, Linda; Arpicco, Silvia; Dosio, Franco; Zonari, Daniele; Cravotto, Giancarlo; Tagliapietra, Silvia; Serpe, Loredana; Turci, Francesco; Barge, Alessandro

doi: 10.1039/d0ra03944fpmid: 35516637

Paulo de Campos da Costa, João; Assis, Marcelo; Teodoro, Vinícius; Rodrigues, Andre; Cristina de Foggi, Camila; San-Miguel, Miguel Angel; Pereira do Carmo, João Paulo; Andrés, Juan; Longo, Elson

doi: 10.1039/d0ra03179hpmid: 35516617

This study demonstrates that the electron beam irradiation of materials, typically used in characterization measurements, could be employed for advanced fabrication, modification, and functionalization of composites. We developed irradiation equipment using an electron beam irradiation source to be applied in materials modification. Using this equipment, the formation of a thick Ag film on the Ag3PO4 semiconductor is carried out by electron beam irradiation for the first time. This is confirmed by various experimental techniques (X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy) and ab initio molecular dynamics simulations. Our calculations demonstrate that, at the earlier stages, metallic Ag growth is initiated preferentially at the (110) surface, with the reduction of surface Ag cations forming metallic Ag clusters. As the (100) and (111) surfaces have smaller numbers of exposed Ag cations, the reductions on these surfaces are slower and are accompanied by the formation of O2 molecules.

Tian, Shiwei; Jiang, Chao; Chen, Feifei; Yu, Fapeng; Li, Yanlu; Cheng, Xiufeng; Wang, Zhengping; Zhao, Xian

doi: 10.1039/d0ra02769cpmid: 35516613

The trigonal lithium niobate crystal (LiNbO3, LN) is a multi-functional material that possesses excellent nonlinear optical, pyroelectric and piezoelectric properties. In this work, the irradiation damage mechanism and stability of the electro-elastic properties of LN crystals irradiated with different doses (1013–1016 ions per cm2) of 6 MeV Xe23+ ions were evaluated for potential piezoelectric applications under irradiation conditions below 650 °C. The vacancy formation energies for Li, O, and Nb atoms are much lower than the irradiation energy of 6 MeV, with the lowest vacancy formation energy being obtained for Li, so that a high concentration of vacancies will be generated in LN upon irradiation. The vacancies narrow the band gap and decrease the electrical resistivity after irradiation. In contrast to the electrical resistivity, the relative dielectric permittivity of the LN crystal was found to increase with increasing irradiation dose, due to the weakened chemical bonds and distorted crystal structure, as confirmed by X-ray photoelectron spectroscopy. Despite the irradiation, the effective piezoelectric coefficients of bulk LN crystal remain nearly unchanged, indicating the favorable properties of LN for use under irradiation conditions at temperatures up to 650 °C.

Khoiroh, Ianatul; Lee, Sze Ying; Pirdashti, Mohsen; Lee, Ming-Jer

doi: 10.1039/c9ra09688dpmid: 35516635

By means of molecular dynamics (MD) simulations, we explored the structural properties of polyethylene glycol monolaurate (PEGML) in water and in various aliphatic alcohols (methanol, ethanol, 2-propanol, 2-butanol, tert-butanol, and 1-pentanol). The PEGML and the alcohols were simulated using the optimized potentials for liquid simulations, all-atom (OPLS-AA) force field and water using the extended simple point charge (SPC/E) model. From the isothermal-isobaric (NPT, constant number of particles, constant pressure, and constant temperature) ensemble, we extracted the densities from the simulations and compared them with those from experimental results in order to confirm the validity of the selected force fields. The densities from MD simulations are in good agreement with the experimental values. To gain more insight into the nature of interactions between the PEGML and the solvent molecules, we analyzed the hydrogen-bonds, the electrostatic (Coulomb) interactions, and the van der Waals (Lennard-Jones) interaction energies extracted from MD simulations. The results were further strengthened by computing the solvation free energy by employing the free energy perturbation (FEP) approach. In this method, the free energy difference was computed by using the Bennet Acceptance Ratio (BAR) method. Moreover, the radial distribution functions were analyzed in order to gain more understanding of the solution behavior at the molecular level.

Zhan, Hang; Shi, Qiang Qiang; Wu, Guang; Wang, Jian Nong

doi: 10.1039/d0ra03472jpmid: 35516623

For applications in energy-saving buildings, aerospace industry, and wearable electronic devices, thermally insulating materials (TIMs) are required to possess not only low thermal conductivity but also light weight, mechanical robustness, and environmental stability. However, conventional TIMs can rarely meet these requirements. To overcome this shortcoming, we propose a new strategy for preparing TIMs. This is based on the design of a highly porous structure from carbon nanotubes (CNTs). The CNT structure is constructed by continuous winding of a hollow cylindrical CNT assembly from a high-temperature furnace and subsequent modification by the deposition of amorphous carbon (AC). The resultant sponge-like material is shown to have a record-low density of 2–4 mg cm−3 and a record-low thermal conductivity of 10–14 mW m−1 K−1. Combined with this thermal property, the sponge material also possesses fire-retardancy during burning, mechanical robustness after repeated loading and unloading to a high strain of 90%, and environmental stability from 535 to −196 °C. Such a combination of physical and mechanical properties results from the strengthening of the porous structure by virtue of AC deposition on CNT surfaces and junctions. The high performance of the new TIM constitutes the foundation for it to be used in wide areas, especially under the harsh conditions requiring multifunctionality.

Zou, Lihua; Zheng, Zhaojuan; Tan, Huanghong; Xu, Qianqian; Ouyang, Jia

doi: 10.1039/d0ra03089apmid: 35516629

As a useful and renewable chemical building block from biomass, 2,5-furandicarboxylic acid (FDCA) has become an increasingly desirable platform chemical as a terephthalic acid replacement for polymerization. In this work, an efficient and highly selective biocatalytic approach for the synthesis of FDCA from 5-hydroxymethylfurfural (HMF) was successfully developed using a TEMPO/laccase system coupled with Pseudomonas putida KT2440. TEMPO/laccase afforded the selective oxidation of the hydroxymethyl group of HMF to form 5-formyl-2-furancarboxylic acid as a major product, which was subsequently oxidized to FDCA by P. putida KT2440. Manipulating the reaction conditions resulted in a good conversion of HMF (100%) and an excellent selectivity of FDCA (100%) at substrate concentrations up to 150 mM within 50 h. The cascade catalytic process established in this work offers a promising approach for the green production of FDCA.