RSC Advances

Zhang, Mei-Na; Khan, Shahid; Zhang, Junjie; Khan, Ajmal

doi: 10.1039/d0ra05848cpmid: 35520647

The development of green, economical and sustainable chemical processes is one of the primary challenges in organic synthesis. Herein, we report an efficient and heterogeneous palladium-catalyzed sulfonylation of vinyl cyclic carbonates with sodium sulfinates via decarboxylative cross-coupling. Both aliphatic and aromatic sulfinate salts react with various vinyl cyclic carbonates to deliver the desired allylic sulfones featuring tri- and even tetrasubstituted olefin scaffolds in high yields with excellent selectivity. The process needs only 2 mol% of Pd2(dba)3 and the in situ formed palladium nano-particles are found to be the active catalyst.

Fang, Bin; Ning, Fulong; Hu, Sijia; Guo, Dongdong; Ou, Wenjia; Wang, Cunfang; Wen, Jiang; Sun, Jiaxin; Liu, Zhichao; Koh, Carolyn A.

doi: 10.1039/d0ra04088fpmid: 35520650

Anti-agglomerants (AAs), both natural and commercial, are currently being considered for gas hydrate risk management of petroleum pipelines in offshore operations. However, the molecular mechanisms of the interaction between the AAs and gas hydrate surfaces and the prevention of hydrate agglomeration remain critical and complex questions that need to be addressed to advance this technology. Here, we use molecular dynamics (MD) simulations to investigate the effect of model surfactant molecules (polynuclear aromatic carboxylic acids) on the agglomeration behaviour of gas hydrate particles and disruption of the capillary liquid bridge between hydrate particles. The results show that the anti-agglomeration pathway can be divided into two processes: the spontaneous adsorption effect of surfactant molecules onto the hydrate surface and the weakening effect of the intensity of the liquid bridge between attracted hydrate particles. The MD simulation results also indicate that the anti-agglomeration effectiveness of surfactants is determined by the intrinsic nature of their molecular functional groups. Additionally, we find that surfactant molecules can affect hydrate growth, which decreases hydrate particle size and correspondingly lower the risk of hydrate agglomeration. This study provides molecular-level insights into the anti-agglomeration mechanism of surfactant molecules, which can aid in the ultimate application of natural or commercial AAs with optimal anti-agglomeration properties.

Razavi, Zohreh Sahhaf; Bayat, Mohammad; Hosseini, Hajar

doi: 10.1039/d0ra03910apmid: 35520681

A highly efficient and straightforward synthesis of N-fused heterocyclic compounds including 5-amino-7-(aryl)-8-nitro-N'-(1-(aryl)ethylidene)-3,7-dihydro-2H-thiazolo[3,2-a]pyridine-6-carbohydrazide derivatives is successfully achieved via a five-component cascade reaction utilizing cyanoacetohydrazide, various acetophenones, aromatic aldehydes, 1,1-bis(methylthio)-2-nitroethylene and cysteamine hydrochloride in ethanol at reflux conditions. The new approach involves domino N,S-acetal formation, Knoevenagel condensation, Michael reaction, imine–enamine tautomerization and N-cyclization sequences. The prominent advantages of this protocol include: facility of operation, available and economical starting materials, no need for toxic solvents, high yields and tolerance of a wide variety of functional groups.

Wang, Zhijun; Zhang, Bingjie; Zhang, Yueyan; Yan, Ni; He, Gang

doi: 10.1039/d0ra05483fpmid: 35520648

Organic carbonyl redox polymers, especially conjugated polyimides with multiple reversible redox centers have attracted considerable attention as electrode materials for organic Li-ion batteries. However, the low utilization of carbonyls hindered their potential applications in energy storage. Herein, a novel π-conjugated polyimide (PBPI) based on biphenyl diimide (BPI) containing two seven-membered imide rings is developed. PBPI is used as an anode material for organic Li-ion batteries, which show high conductivity and insolubility in the electrolyte and enable intercalation of four Li-ions per BPI unit, thus contributing to a reversible capacity of 136 mA h g−1 at 100 mA g−1 with coulombic efficiency close to 100%. Moreover, the battery based on PBPI manifested superior high-rate performance (65 mA h g−1 at 2000 mA g−1) as well as significant cycling stability (over 1600 cycles at 100 mA g−1). Remarkably, the full redox-active site (CO) utilization of an aromatic diimide core to achieve its full potential applications is reported for the first time. This work provides a new strategy for developing redox π-conjugated polyimides and accommodation of more alkaline ions for high performance battery systems.

Horbatiuk, Jeffrey; Alazzawi, Lubna; Harris, Carolyn A.

doi: 10.1039/d0ra05128dpmid: 34094506

Bioreactors have become a critical step for the testing of new biomaterials and pharmaceuticals. They need to be controllable, ideally high-throughput, and produce a biologically relevant environment. For example, in the brain, it is essential to recreate multiple flow–pressure profiles daily and mimic brain fluid movement for a bioreactor to be more physiologic. In this study, we demonstrate a scalable system that regulates flow rate, pressure, and pulsation amplitude. We also show that with new microcontroller technology, up to 15 chambers running in parallel is theoretically possible. Our system, the Flow Limiting Operator (FLO), achieves these goals by multiplexing a series of valves and pumps to control pressure and volumetric flow rate instead of relying on head gas pressure. With the ability to control multiple parameters and its ease of use, both scientists and clinicians can use FLO to study the effects of pulsation amplitude of the fluid flow, flow rate, and pressure on intercellular interactions for both biomaterials and pharmaceuticals.

Sharma, Jaswinder; Polizos, Georgios; Hun, Diana; Nawaz, Kashif; Sahore, Ritu

doi: 10.1039/d0ra06114jpmid: 35520683

Hydrophobic hollow silica particles are desirable for several applications such as hydrophobic coatings, thermal insulation, and thermally resistant insulative paints. However, converting hydrophilic particles into hydrophobic particles without compromising their structural integrity is challenging. In this work, we present a low cost strategy to modify the surface of hollow silica particles from hydrophilic to hydrophobic without compromising their structural integrity.

Pathak, Nimai; Ghosh, Partha Sarathi; Mukherjee, Sumanta; Mandal, Balaji Prasad

doi: 10.1039/d0ra01869dpmid: 35520675

Combined photoluminescence (PL) and dielectric studies have been carried out on both undoped and Eu3+ doped LiNbO3 compounds for their potential application in optical–electrical integration for the first time. Special focus has been given to simultaneously tuning both these physical properties. A PL study reveals that the blank compound is a blue emitting material, while upon doping with Eu3+ ions, the emitting color can be tuned from blue to red upon changing the excitation wavelength. Interestingly, the electrical property measurement of this ferroelectric compound showed that upon doping with Eu3+ ions, the remnant polarization was increased significantly. Density Functional Theory (DFT) based calculations were carried out to explain both the optical and electrical properties. It has been found that different defect centers are responsible for the bluish host emission while Eu3+ ions are energetically preferred to occupy the Nb site and gives rise to red emission. The DFT based results also showed that Eu3+ ions induced more distortion into the nearby Nb-site, which is responsible for enhancement of the remnant polarization. Stark-splitting patterns in the PL study also showed that the point symmetry of LiNbO3 upon Eu3+ doping changes from C6v to D3, which indicates that the structure becomes less symmetric. Overall, the study presents a novel approach to designing multifunctional materials for optical–electrical integration application and to tuning their physical properties simultaneously in the desired range.

Anfar, Zakaria; Amedlous, Abdallah; Majdoub, Mohammed; El Fakir, Abdellah Ait; Zbair, Mohamed; Ait Ahsaine, Hassan; Jada, Amane; El Alem, Noureddine

doi: 10.1039/d0ra05220epmid: 35520655

Herein, ethylenediamine functionalized porous carbon (PC-ED/1.5) was synthesized, then characterized by various methods and finally used as a functional material for Cu(ii) and Pb(ii) ion removal from water. XPS revealed the presence of numerous functionalities within the surface of PC including –NH and C–N–C groups. Furthermore, SBET, RS, XRD and FTIR analyses confirmed the changes implemented on the PC surface. Thereafter, a systematic study was implemented to analyze the interactions of the PC-ED/1.5 surface with Cu(ii) and Pb(ii) heavy metal ions. Hence, adsorption experiments showed that the PC-ED/1.5 exhibits maximum adsorption capacities of 123.45 mg g−1 and 140.84 mg g−1 for Cu(ii) and Pb(ii), respectively. Moreover, in situ electrostatic interactions occurring between the divalent cation and the PC-ED/1.5 functional groups was investigated. The mechanism involves chelation processes, electrostatic interactions and mechanical trapping of the metal ions in the adsorbent pores. Interestingly, a synergistic effect of the pores and surface active sites was observed. Finally, by using alginate bio-polymer we prepared membrane films of PC-ED/1.5 which showed long-term stability, regeneration capabilities and high mass recovery.

Kim, Kyeongha; Kim, Hun Young; Oh, Kyungsoo

doi: 10.1039/d0ra06820apmid: 35520643

A facile access to fused pyrimidin-4(3H)-one derivatives has been established by using the metal-free ortho-naphthoquinone-catalyzed aerobic cross-coupling reactions of amines. The utilization of two readily available amines allowed a direct coupling strategy to quinazolinone natural product, bouchardatine, as well as sildenafil (Viagra™) in a highly convergent manner.

Alinejad, Abutaleb; Raissi, Heidar; Hashemzadeh, Hassan

doi: 10.1039/d0ra06705apmid: 35520638

The objective of this study is to develop a controlled and water-soluble delivery system for doxorubicin (DOX) based on the coating of graphene (G) with a smart polymer. A combination of polyethyleneimine (PEI) and G–DOX is investigated by performing density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Several parameters have been employed to evaluate the effect of PEI on the adsorption and release mechanisms of DOX. The obtained results indicated that the binding energy of the drug molecule on G in the presence of PEI is enhanced by about 20% under neutral conditions, whereas the drug absorption becomes weaker in an acidic environment so that DOX could be separated from the carrier surface using near-infrared radiation (NIR). Based on the atom in molecule (AIM) theory, two hydrogen bonds with strengths of about −12.59 and −39.99 kJ mol−1 have been established. Furthermore, evaluating the dynamic behavior of the designed systems in water solution shows that the polymer in physiological pH rapidly adsorbed on the drug–carrier complex. However, at acidic pH, it is quickly desorbed from the carrier surface and the G–DOX complex can be exposed to cancer cells. The obtained results of the present research may be used in future experimental work to design smart DDSs.