New Journal of Chemistry最新文献

Considerable interest in designing multi-responsive soft materials for diverse applications is leading to the development of systems that are embedded with functional groups with stimuli-responsive characters. Surface-active ionic liquids (SAILs) with an ability to form various structural aggregates represent an interesting candidate for designing soft materials with stimuli-responsive characters. Embedding photo-responsive moieties into SAILs with existing pH-responsive properties can unlock a broader range of potential uses. Herein, we prepared photo- and pH-responsive catanionic giant vesicles (GVs) through a synergetic interaction between the pH-responsive choline oleate ([Ch][Ol]) and photo-responsive (4-methyl-4-(2-(octyloxy)-2-oxoethyl)) morpholin-4-ium(E)-4-((4-(dimethylamino) phenyl) diazinyl) benzenesulfonate ([C₈EMorph][MO]). The photo-responsiveness in the GVs was introduced through [C₈EMorph][MO], which shows E–Z isomerisation under 460 nm light irradiation, whereas the pH-responsive character was obtained through [Ch][Ol]. We used absorbance measurements complimented with a computational study to characterize the photo-responsive behaviour. Irradiating the GVs with light of suitable wavelength and changing the pH of the system altered the behaviour of the aggregates. Small-angle neutron scattering (SANS) analysis showed that, before irradiation, the size of the bilayer thickness of the GVs was 28 Å and after irradiation it was increased to 31 Å, leading to an increment in the overall size of the GVs. This was due to the formation of Z-[C₈EMorph][MO] after irradiation, which leads to a slight alteration in the interactions between both SAILs. Moreover, the change in pH of the vesicles caused alterations in the size and shape of the vesicles, as confirmed through the SANS analysis. The stability of the GVs in terms of temperature, dilution, and time was analysed to characterise the GVs for practical applications. The insights gained from this study could be valuable for developing materials for these applications such as probes, cargo carriers, and microreactors in future.

A series of linear block polymers and random polymers were synthesized by interfacial polycondensation using two bisphenols with similar structures, bisphenol S (BPS) and bisphenol A (BPA), and terephthaloyl chloride and isophthaloyl chloride. Random polymers and block polymers with the expected topology were structurally characterized by ¹H NMR, FTIR, GPC, WAXD, and Raman spectroscopy. The results demonstrated that there was no significant difference in the thermal stability of the block and random polyarylates, which was due to the fact that the covalent bonds of the linked monomers did not change substantially, and the bond energies were the same. However, due to the alteration of the molecular sequence structure, the block polymer exhibited a lower glass transition temperature, a pronounced melting peak, and better solubility. With physical cross-linking points consisting of microcrystalline phases formed by the relatively regular molecular chain structure, the block polyarylates exhibited a higher modulus of elasticity than the random polyarylates. This illustrated that it is possible to prepare new functional polyarylates without changing the monomer composition, but only by manipulating the reaction process.

The application of well-tailored semiconducting hybrid composites in purifying contaminated surface water is a greatly sought-after field. TiO₂, a prominent photocatalyst with higher band energy, was hybridised with strontium-doped Co₃O₄ nanoparticles for the effective degradation of malachite green (MG) dye under solar light. A TiO₂/Sr–Co₃O₄ composite with excellent visible light absorption ability and narrow band gap energy (E_g = 2.0 eV) was synthesised by applying a simple co-precipitation method. The structural, morphological and optical properties of the synthesized catalyst were analysed through XRD, FE-SEM, EDS, HR-TEM, FTIR, Raman spectroscopy, UV-DRS and surface properties were investigated via BET analysis. The doping of strontium metal on Co₃O₄ (p-type) acted as an electron facilitator to TiO₂ (n-type) at the p–n hetero-junction of the TiO₂/Sr–Co₃O₄ composite, increasing its efficiency towards photo-degradation of MG dye compared to pure Co₃O₄, TiO₂, Sr–Co₃O₄, and Co₃O₄–TiO₂ under solar irradiation. A maximum degradation of 92% occurred at pH 10 with a dye concentration of 20 ppm and catalyst dose of 0.02 g L⁻¹ in 60 min under solar irradiation. The photocatalytic degradation of MG dye by TiO₂/Sr–Co₃O₄ followed pseudo first-order kinetics. TiO₂/Sr–Co₃O₄ exhibited good stability by maintaining 80% degradation of MG dye after five consecutive cycles.

As a promising anode candidate for sodium-ion batteries (SIBs), tin-based oxides suffer from rapid capacity fading, greatly limiting their practical applications. Herein, we designed and synthesized three cobalt–tin oxide composites (CSOs), with different degrees of crystallinity by controlling the annealing temperature, to understand the effect of amorphous and crystalline structures on the Na⁺ storage behavior of tin-based alloy anodes. Theoretical calculations suggest that the amorphous CSO (CSO-A) presents the lowest binding energy with Na⁺ and the lowest diffusion barriers of Na⁺ in comparison with that of crystallinity samples (CSO-AC and CSO-C), indicating that the amorphous CSO is the most energetically favorable for Na insertion. Similarly, the experimental results suggest that CSO-A delivers the highest initial specific capacity; however, it presents the worst cycling stability and reversibility. CSO-C displays the best cycling stability but the lowest specific capacity. Interestingly, the CSO-AC sample with both amorphous and crystalline domains achieves the best comprehensive electrochemical performance. Quantitative analysis of the electrochemical process reveals that controlled crystallinity significantly impacts the microstructure and band gap of CSO, which will further affect the reversibility of the conversion reaction and the percent of pseudocapacitance contribution. Our work suggests that, for the alloy anode, rational regulation of crystallinity is a substantial approach to improve capacity retention.

Arjunolic acid (AA) is a pentacyclic triterpene acid with various potent biological activities. In this work, arjunolic acid was isolated from the heartwood of Terminalia arjuna, and a series of novel arjunolic acid acetals were synthesized and characterized. The anti-cancer activity of the synthesized acetals was investigated against sixty cell lines from nine different types of cancers at the National Cancer Institute (NCI). Compounds AA-2, AA-4, AA-9, and AA-18 demonstrated significant activity against colon cancer. These compounds were selected for further studies against murine colon cancer cell line CT-26. Mechanistic studies of the most active compound AA-9 on CT-26 cells revealed cell cycle arrest in the G₂/M phase, which induces ROS generation in cells, leading to cell death. Additionally, compound AA-9 showed better selectivity for tumour cells and non-tumour cells.

An N configuration enriched N-doped activated carbon adsorbent was successfully synthesised using an ammonia-induced N impregnation step with spent tea leaves (STLs) as a carbon precursor. In this study, activated carbon (AC) has been synthesized using a two-step H₃PO₄ activation method. SEM, Raman spectroscopy, N₂ physisorption, ultimate elemental analysis, and XPS were employed to characterise the physicochemical features of the prepared adsorbent. According to the characterisation analysis, the characteristics of the prepared adsorbent solely (either high in the surface area or N-content) are not sufficient enough to achieve good uptake capacity, and this has been demonstrated using the un-doped AC (AC) and commercialised AC (CAC) with a high surface area and N-doped biochar (NC) with a high N content. Through a volumetric adsorption step, it was revealed that the N-doped AC (NA773C) exhibited an improved CO₂ adsorption uptake capacity of 2.66 mmol g⁻¹, which is about 78%, 400%, and 177% higher than those of NC, AC and CAC, respectively, at 298 K and under atmospheric pressure conditions. With the results obtained from the characterisation analysis, it was found that a high surface area, along with a high N–C composition possessed by NA773C compared to those of other adsorbents endowed it with a high CO₂ uptake capacity.

Metal silicates (Zn, Mn, Ni and Co) were synthesized from natural green algae (GAs) as supercapacitor electrodes. In this study, a multi-step treatment with two kinds of porogens was used to produce a larger specific surface area and more abundant hierarchical pores. Firstly, GAs were treated with 1.0 M NaCl solution to prepare large pores. Secondly, metal silicates were synthesized from GAs using a hydrothermal reaction. Lastly, the as-synthesized samples were soaked in 3.0 M NaOH solution to obtain the products (m-C-MSi, M = Zn, Mn, Ni and Co). Compared with the composites without multi-step treatment, the synthetic materials in this research possess excellent electrochemical properties both as electrodes and as HSCs. This work proved that the multi-step treatment with porogens is an effective method to enhance the electrochemical performance of metal-silicate supercapacitors.

This work aims to investigate novel structures based on 2-methylbenzylamine cations [(C₈H₁₂N)₂Co(SCN)₄] (1) and [(C₈H₁₂N)SCN] (2). The novel complexes were characterized and investigated by various techniques such as differential thermogravimetry analysis, FT-IR, UV-visible spectroscopy, impedance complex analysis, molecular modeling based on DFT calculations, and molecular docking as potent anti-inflammatory agents. Based on the reported results of these characterization tools, the desired complex phases were confirmed. These novel compounds were characterized by FTIR analysis, which supported the presence of surface ligand groups of thiocyanates, and UV-visible spectroscopy showed the optical transparencies of the titled compounds in addition to the confirmation of the electronic transition. Complex packing occurred through the N–H⋯S and N–H⋯N H-bond interactions, forming a ring in addition to CH-interactions, resulting in a 3-D network. Finally, molecular docking occurred for both complexes, which suggests that the complexes have anti-inflammatory potential.