RSC Advances

Song, Yuxuan; Zhang, Qun; Zou, Xinyuan; Fan, Jian; Wang, Sicai; Zhu, Yan

doi: 10.1039/d4ra07300bpmid: 39802479

Supercritical CO2, as an environmentally friendly and pollution-free fluid, has been applied in various EOR techniques such as CO2 flooding. However, the low viscosity of the gas leads to issues such as early breakthrough, viscous fingering, and gravity override in practical applications. Although effective mobility-control methods, such as CO2 WAG (water alternating gas)–, CO2 foam-, and gel-based methods, have been developed to mitigate these phenomena, they do not fundamentally solve the problem of the high gas–oil mobility ratio, which leads to reduced gas sweep efficiency. Adding CO2 direct thickeners to displacing fluid can increase its viscosity, achieve deeper mobility control, and thus improve the CO2 flooding oil-recovery effect. Unlike other methods, direct thickeners can alter the physical and chemical properties of CO2, making it a fundamentally effective means of achieving mobility control. This approach can be applied in various reservoir environments and formations, or it can assist other methods for more in-depth mobility control. This article reviews the development and application of CO2 direct thickeners and introduces the thickening mechanisms and effects of different types of thickeners as well as their existing problems and future development directions.

Córdova, Teresa; Enriquez-Medrano, Francisco Javier; Magaña, Ilse; García-Zamora, Maricela; Jimenéz-Reyes, Nelson A.; Mata-Padilla, José M.; Cabrera-Álvarez, Edgar E.; Valencia, Luis; Díaz de León, Ramón

doi: 10.1039/d4ra07481epmid: 39802471

The development of materials from renewable resources has been increasing, intending to reduce the consumption of fossil sources, with terpenes being one of the main families that reduce the consumption of isoprene. The study of the binary catalytic system neodymium versatate/dibutyl magnesium (NdV3/Mg(n-Bu)2), for the coordination homopolymerization of β-myrcene and β-farnesene, was carried out analysing different [Nd] : [Mg] ratios (between 4 and 10). Reporting conversions of 92% and 83% at an [Nd] : [Mg] ratio of 8 for polymyrcene (PMy) and polyfarnesene (PFa), respectively, and microstructures comprising 1,4 content above 80% for both polymers (PMy, cis-59% and PFa, cis-83%). It was observed that PFa samples presented a higher 1,4-cis content in relation to PMy samples, presumably due to the size of the side group present in the monomer structure and due to steric hindrance; similarly, a 3,4 content of 14% (PMy) and 10% (PFa) was observed. The glass transition temperature of the PMy samples ranged from −63.7 °C to −66.5 °C, while for the PFa samples, it was between −75.4 °C and −75.5 °C. The binary [Nd] : [Mg] system used in the study predominantly exhibited a 1,4-cis content at [Nd] : [Mg] ratios of 8.

Balusamy, Sri Renukadevi; Balamurugan, Mani; Purushothaman, Sumitha; Somasundaram, Sivaraman; Elsadek, Mohamed Farouk; Sohn, Daewon; Almutairi, Saeedah Musaed; Mijakovic, Ivan; Rahimi, Shadi; Perumalsamy, Haribalan

doi: 10.1039/d4ra06377epmid: 39802467

Given that stomach cancer is the fourth leading cause of cancer-related death, there is a need to develop new drugs. Among various methods, metal-based coordination compounds are considered as an efficient strategy against this type of cancer. Similarly, the benzimidazole moiety plays a crucial role in biology; thus, various benzimidazole-based compounds have been found to be active as potential anticancer drugs and are currently used in clinical trials. In this study, we explored the benzimidazole-based cobalt(ii) complex as an anticancer agent against AGS stomach cancer cell lines. Interestingly, the MTT assay of the Co-NTB complex shows a lower IC50 value of 4.25 μg mL−1 compared to cisplatin, which has an IC50 of 7.5 μg mL−1 against AGS cell lines. Light microscopy and Hoechst/propidium iodide dye staining clearly indicate that the complex damages DNA, leading to cell death through an apoptotic pathway. The apoptotic cell death pathway was further complemented by Lysotracker and Mitotracker staining, as well as transmission electron microscopy (TEM) imaging. Overall, the Co-NTB complex acts as an effective anticancer agent against AGS stomach cancer cell lines, with apoptotic cell death induced by targeting cellular organelles and DNA.

Vitali, Valentina; Zineddu, Stefano; Messori, Luigi

doi: 10.1039/d4ra07449apmid: 39802470

Due to their considerable chemical diversity, metal compounds are attracting increasing and renewed attention from the scientific and medical communities as potential antimicrobial agents to combat the growing problem of antibiotic resistance. The development of metal compounds as antimicrobial agents typically follows classical drug discovery procedures and suffers from the same problems; indeed, these procedures can be very expensive and time-consuming, and carry an intrinsically high risk of failure. Here, we show how some established drug discovery approaches can be conveniently and successfully applied to antimicrobial metal compounds to provide some shortcuts for faster clinical translation of new treatments. Specifically, we refer to (i) drug repurposing, (ii) drug combination and (iii) drug targeting by bioconjugation; some relevant examples will be illustrated.

Calisir, Ilkan; Bennett, Elliot L.; Yang, Xiantao; Xiao, Jianliang; Huang, Yi

doi: 10.1039/d4ra07419jpmid: 39802466

In response to the demand for epoxy-based dielectric substrates with low dielectric loss in high-frequency and high-speed signal transmission applications, this study presents a surface-engineered filler material. Utilizing ball-milling, surface-modified aluminum flakes containing organic (stearic acid) and inorganic (aluminum oxide) coatings are developed. Incorporation of the filler into the epoxy matrix results in a significant increase in dielectric permittivity, εr, by nearly 5 times (from 4.3 to 21.2) and nearly an order of magnitude reduction in dielectric loss, tan δ, (from 0.037 to 0.005) across the 1 to 10 GHz frequency range. Extension of this method to glass fabric-reinforced epoxy-based substrates, resembling widely used FR4 in printed circuit boards, exhibits minimal permittivity variation (4.5–5.4) and considerable reductions in dielectric loss (from 0.04 to 0.01) within the same frequency range. These enhancements are attributed to improved filler dispersion and suppression of electron transport facilitated by double-layer coatings on the flake surface under varying electric fields. The findings highlight the potential of surface-modified aluminum flakes as a promising filler material for high-frequency and high-speed substrate applications requiring low-loss.

Long, Zuhuan; Gao, Yu; Zhang, Yaojun; Ma, Weili; Zheng, Jiqi; Liu, Yuxin; Ding, Fu; Sun, Yaguang; Xu, Zhenhe

doi: 10.1039/d4ra07018fpmid: 39802463

Photocatalytic technology for removing organic dye pollutants has gained considerable attention because of its ability to harness abundant solar energy without requiring additional chemical reagents. In this context, YF3 spheres doped with Yb3+, Er3+, Tm3+ (YF) are synthesized using a hydrothermal method and are subsequently coated with a layer of graphitic carbon nitride (g-C3N4) with Au nanoparticles (NPs) adsorbed onto the surface to create a core–shell structure, designated as YF3: Yb3+, Er3+, Tm3+@C3N4-Au (abbreviated as YF@CN-Au). The core–shell composites demonstrate remarkable stability, broadband absorption, and exceptional photocatalytic activity across the ultraviolet (UV) to near-infrared (NIR) spectral range. Notably, by optimizing the amount of Au loaded, excellent methyl orange (MO) degradation rates of 0.068 min−1 under UV light and 0.423 h−1 under light excitation with λ > 420 nm can be achieved. Even under low-energy NIR light (λ > 800 nm), a degradation rate of 0.087 h−1 was reached, indicating a significantly enhanced degradation effect compared to YF@CN without Au loading. The high performance of the core–shell composite is attributed to its unique structure, which enables efficient transfer of energy and charge carriers, thereby promoting charge separation and suppressing recombination. Furthermore, this article reveals and discusses three distinct photocatalytic mechanisms under UV, visible, and NIR light. This study underscores the considerable promise of core–shell composites in developing efficient g-C3N4-based broadband photocatalysts, focusing on comprehensive utilization of the solar spectrum through the synergistic effects of plasma and upconversion materials.

Wu, Ruixiang; Zhang, Hanyan; Liu, Wenhua; Bai, Renao; Zheng, Delun; Tian, Xiufang; Lin, Weikai; Li, Lejian; Ke, Qianwei

doi: 10.1039/d4ra07712apmid: 39802465

This research focuses on the development of a novel Ru-doped TiO2/grapefruit peel biochar/Fe3O4 (Ru-TiO2/PC/Fe3O4) composite catalyst, which exhibits exceptional photocatalytic efficacy under simulated solar light irradiation. The catalyst is highly effective in the degradation of rhodamine B (RhB), methylene blue (MB), methyl orange (MO), as well as actual industrial dye wastewater (IDW), and can be recovered magnetically for multiple reuse cycles. Significantly, the PCTRF-100 sample exhibited degradation efficiencies of 99.4% for RhB and 99.8% for MB within 60 min, and 98.04% for MO within 120 min. In the case of actual dye wastewater, a reduction in chemical oxygen demand from 1540 mg L−1 to 784 mg L−1 was achieved within 300 min, corresponding to a degradation rate of 46.81%. The remarkable photocatalytic activity observed is primarily attributed to the synergistic interactions among Ru-TiO2, biochar, and Fe3O4, which effectively facilitate the separation and migration of electron–hole pairs in TiO2.

Okba, Dina; Hassan, Sameh; Abdel Aleem, Abdel Aleem H.; Shehab El-din, Mohamed T.; El Tantawy El Sayed, Ibrahim; Abou-Elyazed, Ahmed S.

doi: 10.1039/d4ra07779bpmid: 39802478

Supercapacitors (SCs) are gaining attention in energy storage due to their high-power density, rapid charge/discharge ability, and long life cycle. Improving these features relies on developing advanced electrode materials with better energy storage properties. This study explores UiO-66, a zirconium-based metal–organic framework (MOF), which offers advantages like a large surface area, tunable pore sizes, and stability. However, its poor electrical conductivity limits its use in supercapacitors. Herein, we applied the Hummers' method to oxidize UiO-66, creating an oxidized form, H-UiO-66, with enhanced conductivity. This material was characterized by various techniques, including SEM-EDX, XRD, XPS, FTIR, and BET analysis, while electrochemical tests (GCD, CV, and EIS) confirmed a significant improvement in specific capacitance—82.8 F g−1 for H-UiO-66 versus 0.18 F g−1 for pristine UiO-66 at 1 mA. These improvements stem from increased conductivity and electrochemical activity due to UiO-66 graphitization, highlighting the Hummers' method's effectiveness in transforming UiO-66 into a viable supercapacitor material.

Bu, Wen-Han; Asilebieke, Ayakuzi; Han, Lu-Yang; Xu, Yang; Zhou, Tao; Chu, Jian-Jun

doi: 10.1039/d4ra06607cpmid: 39802476

Introduction: to address the issue of burst drug release in antibiotic-loaded poly(methyl methacrylate) (PMMA) bone cement (ALBC), this study involved preparation of novel PMMA bone cement and determination of its antibacterial activity, biocompatibility, compressive properties, maximum temperature, and setting time. Methods: a novel acrylic monomer, which contains the 3,4-dichloro-5-hydroxyfuran-2(5H)-one (DHF), was synthesized and utilized to develop non-leaching antibacterial PMMA bone cement (NLBC), designated as DHF-methacrylic acid (DHF-MAA) bone cement. In the preparation of this bone cement, DHF-MAA served as a key component of the liquid phase. Its antibacterial activity was determined using a surface antibacterial assay. The biocompatibility of the cement was evaluated through a rabbit-suspended erythrocyte hemolysis test, assessment of the relative proliferation rate of mouse embryonic osteoblast precursor cells (MC3T3-E1) using the CCK-8 method, and an acute toxicity test in mice. The assessment of compressive properties includes both compressive strength and compressive modulus before and after aging. Results: DHF-MAA bone cement exhibited antibacterial activity, excellent biocompatibility, and acceptable compressive properties; in particular, the 10% DHF-MAA bone cement, achieved 100% antibacterial activity, excellent biocompatibility, and a compressive strength that met the compressive value, as stated in ISO 5833. Conclusions: in this study, novel antibacterial non-leaching DHF-MAA bone cement was synthesized and evaluated for its antibacterial activity, biocompatibility, and compressive properties. In particular, the 10% DHF-MAA bone cement exhibited excellent antibacterial activity, biocompatibility, and acceptable compressive properties. As such, this cement formulation warrants further characterization with a view to using it to anchor cemented arthroplasties.

Tang, Xufang; Jin, Dingfeng; Zhao, Jun; Jin, Min

doi: 10.1039/d4ra90157fpmid: 39802468

Retraction of ‘Color tuning of Bi3+-doped double-perovskite Ba2(Gd1−x,Lux)NbO6 (0 ≤ x ≤ 0.6) solid solution compounds via crystal field modulation for white LEDs’ by Xufang Tang et al., RSC Adv., 2020, 10, 25500–25508, https://doi.org/10.1039/D0RA03793A.