RSC Advances

Wang, B.; Liu, F. Q.

doi: 10.1039/d0ra05343kpmid: 35520037

In this study, the synthesis of small molecules and use of an improved “one-pot” method to synthesize the reversible addition–fragmentation chain transfer polymerization (RAFT) reagents have been reported. By comparing with the RAFT reagents synthesized by the traditional “step-by-step” method, it was observed that the reagents synthesized by the two methods had the same structure, however, the improved “one-pot” preparation method results in a significantly higher yield. Subsequently, two different macromolecular CTA segments (PVP-CTA-PVP and PDMAEMA-CTA-PDMAEMA) were prepared by RAFT polymerization, followed by the synthesis of the block polymer PDMAEMA-b-PVP-CTA-PVP-b-PDMAEMA. Through FITR, NMR, GPC and DLS analysis of the block polymer, it was observed that the isotacticity gradually became dominant as the degree of polymerization increased. Further, using NMR spectroscopy to study the effect of pH on the block polymer, the ionization degree of the synthesized polymer in the tumor tissue environment was observed to range between 86.32% to 99.50%, which proved that the synthesized polymers exhibit significant prospects in the medical application.

Ghaffar, Abdul; Ali, Ghulam; Zawar, Sidra; Hasan, Mariam; Mustafa, Ghulam M.; Atiq, Shahid; Ramay, Shahid M.

doi: 10.1039/d0ra04004epmid: 35520053

With the industrial revolution in electronics, the demand for lithium-ion batteries, particularly those designed for electric vehicles and energy storage systems, has accelerated in recent years. This continuously increasing demand requires high-performance electrode materials, as commonly used graphite anodes show limited lithium intercalation. In this context, Ni-substituted ZnCo2O4 nanostructures, thanks to their high storage capacity, have potential for use as an anode material in lithium-ion batteries. Structural analysis concludes that the prepared materials show improved crystallinity with increasing Ni at the Zn-site in ZnCo2O4. The intermediate composition, Zn0.5Ni0.5Co2O4, of this series exhibits a specific capacity of 65 mA h g−1 at an elevated current rate of 10 A g−1. The lithium insertion/extraction mechanism is investigated via cyclic voltammetry, showing two redox peaks from ZnCo2O4 and a single redox peak from NiCo2O4. Additionally, the lithium diffusion coefficient in the prepared electrodes is computed to be 2.22 × 10−12 cm2 s−1 for the intermediate composition, as obtained using cyclic voltammetry. Electrochemical impedance spectroscopy is used to observe the charge transport mechanism and the charge transfer resistance values of all the samples, which are calculated to be in the range of 235 to 306 Ω.

Yan, Zhangyuan; Li, Jialin; Ye, Geting; Chen, Tao; Li, Meimei; Liang, Yanmin; Long, Yuhua

doi: 10.1039/d0ra05532hpmid: 35520073

A pair of uncommon fused multicyclic polyketides with a two- spiro-carbon skeleton, (±)-isoepicolactone, (±)-1, and one new isobenzofuranone monomer (4), together with four other known biosynthetically related compounds were isolated from the fermentation of an endophytic fungus, Epicoccum nigrum SCNU-F0002, which was isolated from the fresh fruit of the mangrove plant Acanthus ilicifolius L. Comprehensive spectroscopic analysis, X-ray crystallography, together with calculated ECD, were employed to define the structures. The antibacterial and COX-2 inhibitory activities of the compounds (1–6) were evaluated. A possible biogenetic pathway of (±)-isoepicolactone was confirmed.

Chimupala, Yothin; Phromma, Chitsanupong; Yimklan, Saranphong; Semakul, Natthawat; Ruankham, Pipat

doi: 10.1039/d0ra04746epmid: 35520042

Conventionally, composite materials are usually employed as a catalyst in piezo-photocatalytic dye wastewater treatment. Here, we report the synthesis of ZnO nanoparticles, as a single-component catalyst, by surfactant-assisted precipitation in which the size of ZnO nanoparticles (20–100 nm) can be simply controlled by the use of Tween80 as a surfactant. Although, ZnO nanoparticles exhibited appreciable photocatalytic activities for the degradation of methylene blue (MB) dye, upon the addition of a mechanical force, the photocatalytic dye degradation efficiency was substantially improved. Furthermore, we postulated that the surface properties of ZnO play an important role in charge transfer phenomena based on photoluminescence results together with functional groups on the surface of ZnO. In addition, application of single-component ZnO in piezo-promoted photocatalytic degradation of cationic and anionic dyes was accomplished. Our results regarding the behaviour of single-component ZnO nanoparticles under vibrational energy in addition to their conventional solar harvesting can provide a promising strategy for developing photocatalysts for practical wastewater treatment.

Feng, Chao; Tian, Xingling; Wang, Xiaoqiang; Cui, Mengmeng; Xu, Chuantao; Wang, Weimin; Wang, Wei

doi: 10.1039/d0ra01161dpmid: 35520052

We synthesised a silicon dioxide nanosphere with a novel nanostructure by loading salicylic acid (SA) as a plant disease resistance inductor to prolong plant life. The SA nanosphere was evaluated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, N2 adsorption method, enzyme activity test and pot experiments. The results demonstrated that the SA nanosphere induced the activities of polyphenol oxidase, phenylalanine ammonia-lyase, peroxidase, and chitinase to enhance plant immunity to inhibit Phytophthora nicotianae. Its SA loading capacity reached approximately 80%. The SA nanospheres exhibited a sustained release and maintained its resistance effect at 84.79% after 15 days. Thus, the SA nanospheres could gradually release SA to enhance inhibitive enzyme activity in diseased plants. Furthermore, finite element method was used to establish different nanosphere models and analyse the SA releasing process. SA concentration sharply increased near the nanospheres, and SA was slowly released to the solution. This SA nanosphere will have a great potential in future environmental-friendly practical application.

Xu, Feng; Chen, Jian-Li; Jiang, Zhi-Jiang; Cheng, Peng-Fei; Yu, Zhi-Qun; Su, Wei-Ke

doi: 10.1039/d0ra05715kpmid: 35520060

In this contribution, a protocol was established for the selective catalytic hydrogenation of nitroarenes to the corresponding N-arylhydroxylamines. The reduction of 1-(4-chlorophenyl)-3-((2-nitrobenzyl)oxy)-1H-pyrazole, an intermediate in the synthesis of the antifungal reagent pyraclostrobin that includes carbon–chlorine bonds, benzyl groups, carbon–carbon double bonds and other structures that are easily reduced, was chosen as the model reaction for catalyst evaluation and condition optimization. Extensive passivant evaluation showed that RANEY®-nickel treated with ammonia/DMSO (1 : 10, v/v) afforded the optimal result, especially with a particle size of 400–500 mesh. To combine the modified catalyst with continuous-flow reaction technology, the reaction was conducted at room temperature, rendering the desired product with a conversion rate of 99.4% and a selectivity of 99.8%. The regeneration of catalytic activity was also studied, and an in-column strategy was developed by pumping the passivate liquid overnight. Finally, the generality of the method was explored, and 7 substrates were developed, most of which showed a good conversion rate and selectivity, indicating that the method has a certain degree of generality.

Ishimoto, Takayoshi; Tsukada, Satoru; Wakitani, Shin; Sato, Kenji; Saito, Daiki; Nakanishi, Yuki; Takase, Sakino; Hamada, Takashi; Ohshita, Joji; Kai, Hiroyuki

doi: 10.1039/d0ra02909bpmid: 35520051

Toward the design and manipulation of innovative materials, we propose a new concept called “model-based research (MBR)”. In MBR, measurable physical and chemical properties of materials are mathematically modelled by explanatory parameters obtained by computer simulation from an atomistic point of view. To demonstrate the potential of MBR, we modelled the molecular weights of a series of polysilsesquioxanes with respect to the H2O/silane molar ratio employed for the polymerization of monomers bis(triethoxysilyl)methane, ethane, ethylene, and acetylene (BTES-M, -E1, -E2, and -E3), as an example. The equation y = axn well reproduced the behaviour of the molecular weights of the BTES series, in which a and n were obtained using the calculated molecular parameters for monomers as the explanatory parameters. Detailed understanding and discussion were theoretically possible on the basis of the mathematical model. We predicted the molecular weights of polymers that would be obtained from monomers BTES-P and BTES-Ph with C3H6 and C6H4 as the spacer, respectively, using the mathematical model. Experimental validation of these polymers clearly showed the possibility of qualitative categorization. Our proposed concept, MBR, is a powerful tool to analyse materials science toward innovative materials design.

Yeo, Sunmog; Cho, Won-Je; Kim, Dong-Seok; Lee, Chan Young; Hwang, Yong Seok; Suk, Jae Kwon; Kim, Chorong; Ha, Jun Mok

doi: 10.1039/d0ra05073cpmid: 35520065

H+ irradiation increases the surface hardness of polycarbonate. Nano indentation measurement shows that the hardness increases up to 3.7 GPa at the dose of 5 × 1016 # cm−2 and at the irradiation energy of 150 keV. In addition, the hardness increases with the dose and the energy of H+ irradiation. In accordance with the nano indentation measurement, the Fourier-transform infrared spectroscopy (FTIR) depends on the dose and energy of H+ irradiation. The peak at ∼1500 cm−1 for the aromatic ring and the peak at ∼1770 cm−1 for the CO stretch decrease with increasing dose and energy, while the increase of the dose and energy develops a new CO stretch vibration at ∼1700 cm−1 and forms aromatic hydrocarbons at ∼1600 cm−1. X-ray diffraction experiments are also consistent with the nano indentation measurement and FTIR spectra. Based on the experiments, we discuss a possible mechanism of the surface hardness enhancements by ion beam irradiation.

Kaushal, Sandeep; Kaur, Manpreet; Kaur, Navdeep; Kumari, Vanita; Singh, Prit Pal

doi: 10.1039/d0ra04432fpmid: 35520086

Graphene is one of the astounding recent advancements in current science and one of the most encouraging materials for application in cutting-edge electronic gadgets. Graphene and its derivatives like graphene oxide and reduced graphene oxide have emerged as significant nanomaterials in the area of sensors. Furthermore, doping of graphene and its derivatives with heteroatoms (B, N, P, S, I, Br, Cl and F) alters their electronic and chemical properties which are best suited for the construction of economical sensors of practical utility. This review recapitulates the developments in graphene materials as emerging electrochemical, ultrasensitive explosive, gas, glucose and biological sensors for various molecules with greater sensitivity, selectivity and a low limit of detection. Apart from the most important turn of events, the properties and incipient utilization of the ever evolving family of heteroatom-doped graphene are also discussed. This review article encompasses a wide range of heteroatom-doped graphene materials as sensors for the detection of NH3, NO2, H2O2, heavy metal ions, dopamine, bleomycinsulphate, acetaminophen, caffeic acid, chloramphenicol and trinitrotoluene. In addition, heteroatom-doped graphene materials were also explored for sensitivity and selectivity with respect to interfering analytes present in the system. Finally, the review article concludes with future perspectives for the advancement of heteroatom-doped graphene materials.

Raji Reddy, Chada; Ganesh, Veeramalla; Singh, Ajay K.

doi: 10.1039/d0ra05288dpmid: 35520055

Here, we report controlled E–Z isomeric motion of the functionalized 3-benzylidene-indolin-2-ones under various solvents, temperature, light sources, and most importantly effective enhancement of light irradiance in microfluidic photoreactor conditions. Stabilization of the E–Z isomeric motion is failed in batch process, which might be due to the exponential decay of light intensity, variable irradiation, low mixing, low heat exchange, low photon flux etc. This photo-μ-flow light driven motion is further extended to the establishment of a photostationary state under solar light irradiation.