RSC Advances

Zhang, Yanyan; Jiang, Zhelong; Huang, Jianying; Lim, Linda Y.; Li, Wenlong; Deng, Jiyang; Gong, Dangguo; Tang, Yuxin; Lai, Yuekun; Chen, Zhong

doi: 10.1039/c5ra90088cpmid: N/A

Correction for ‘Titanate and titania nanostructured materials for environmental and energy applications: a review’ by Yanyan Zhang et al., RSC Adv., 2015, 5, 79479–79510.

Korsching, Kai R.; Schäfer, Hannes; Schönborn, Josefine; Nimthong-Roldán, Arunpatcha; Zeller, Matthias; Azov, Vladimir A.

doi: 10.1039/c5ra19012fpmid: N/A

Herein we report the first synthesis of a monopyrrolo-tetrathiafulvalene (MPTTF) with two alkyl substituents, performed using a triphenylphosphine-mediated coupling reaction. An Ullmann-type N-arylation reaction was used to prepare a calixarene-based bis-MPTTF receptor, as well as an arylated mono-MPTTF derivative. Complexation studies with electron-deficient compounds showed strongly enhanced affinity of the alkyl-substituted MPTTF derivatives in comparison with the non-substituted MPTTF analogues.

Wang, Yu; Yang, Chunhui; Cheng, Yuan; Zhang, Yingyan

doi: 10.1039/c5ra12028dpmid: N/A

Owing to the superior thermal conductivity of graphene, nanocomposites with graphene fillers dispersed in a polymer matrix become promising in thermal management applications, e.g. serving as thermal interface materials (TIMs) in high power microelectronic devices. However, the thermal conductivity of graphene-based nanocomposites is constrained by the high interfacial thermal resistance between the graphene fillers and polymer matrix. This research focuses on changing graphene–paraffin interfacial thermal transport by employing various treatment methods. Using molecular dynamics (MD) simulations, the effectiveness of hydrogenation, defecting and doping on reducing the graphene–paraffin interfacial thermal resistance is closely investigated. We found that the interfacial thermal resistance can be considerably reduced by the hydrogenation of graphene, while it is insensitive to defecting and doping. From the simulation results of the graphene–paraffin nanocomposites under tensile loading, a lower Young’s modulus and lower tensile strength are observed for the paraffin filled with hydrogenated graphene. The results clearly show that the hydrogenation of graphene exerts opposite effects on the thermal and mechanical properties of graphene–paraffin nanocomposites. Thus hydrogenation is suggested to be used wisely in the graphene–paraffin nanocomposite so as to improve its interfacial thermal conductance at the minimum cost of its mechanical strength.

Khataee, Alireza; Lotfi, Roya; Hasanzadeh, Aliyeh

doi: 10.1039/c5ra14708epmid: N/A

A novel and sensitive flow injection chemiluminescence (CL) method was introduced for the determination of vancomycin based on implementation of l-cysteine capped cadmium sulphide quantum dots (CdS QDs) as a sensitizer in a KMnO4–morin CL system. Investigation of the optical and structural characteristics of the CdS QDs synthesized via a hydrothermal method was accomplished by applying X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL), Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy. Furthermore, the possible mechanism of the proposed CL system was discussed by exploiting the results of the kinetic curves of the CL systems and the spectra of CL, PL, and UV-Vis analysis. The CL intensity of the KMnO4–morin–CdS QDs system was significantly enhanced in the presence of vancomycin. Under the optimized conditions, the increased CL intensity was proportional to vancomycin concentration in the range of 0.004–19 mg L−1, with a detection limit (3σ) of 1.4 μg L−1. Moreover, the proposed CL method was successfully applied for the determination of vancomycin in environmental water samples and commercial pharmaceutical formulations.

Daood, Ghaidaa S.; Basri, Hamidon; Stanslas, Johnson; Fard Masoumi, Hamid Reza; Basri, Mahiran

doi: 10.1039/c5ra14913dpmid: N/A

For the purpose of brain delivery via intravenous administration, the formulation of an azithromycin-loaded nanoemulsion system was optimized utilizing the artificial neural network (ANN) as a multivariate statistical technique. The input effective variables for nanoemulsion formulation were drug loading, surfactant and co-surfactant content, concentration of glycerol, and concentration of vitamin E; the particle size was the output response, because size reduction will improve the stability of the nanoemulsion and the biological efficacy of the drug in vivo after parenteral administration. To achieve the optimum topologies, the ANN was trained by Incremental Back-Propagation (IBP), Batch Back-Propagation (BBP), Quick Propagation (QP), and Levenberg–Marquardt (LM) algorithms for testing data set. The topologies were confirmed by the indicator of minimized root mean squared error (RMSE) for each. Based on this indicator, BBP-5-14-1 was selected as the optimum topology to be used as a final model to predict the desirable particle size and relative importance of the effective variables of the formulation. The ANN analysis showed that the actual particle size (54.7 nm ± 0.8) of the formulated nanoemulsion was quite close to the predicted value (53.9 nm) obtained from the batch back propagation-ANN model, which supports the conclusion that the ANN model has the potential to predict a stable nanoemulsion system that could be used efficiently for the parenteral administration of azithromycin antibiotic.

Bao, Chao; Zhou, Lincheng; Shao, Yanming; Wu, Qiong; Ma, Junjun; Zhang, He

doi: 10.1039/c5ra17971hpmid: N/A

Separation and recycling of noble metal nanocatalysts after catalytic reactions are significant challenges to reduce catalyst cost and avoid waste generation in industrial applications. In this study, Pd-loaded magnetic porous carbon nanospheres (Fe3O4@MC-Pd) were prepared by annealing Fe3O4@MIL-100/PdCl2, which was fabricated through a facile one-pot solvothermal method, at 450 °C in a nitrogen atmosphere. The novel Fe3O4@MC-Pd catalyst consists of a superparamagnetic Fe3O4 core and a chemically inert porous carbon layer, which can protect the Fe3O4 core from extreme external environments and prevent the loss of Pd NPs. The resultant composite material showed excellent catalytic performance in reducing methylene blue with sodium borohydride as a reducing agent and superparamagnetic behavior that enabled the magnetic separation and convenient recovery of the nanocatalysts from the reaction mixture. Moreover, the composite material also showed good thermal and acid stability, fast regeneration ability, and high cyclic stability (>10 cycles without loss of catalytic efficiency). The result shows the nanocatalysts could overcome the drawbacks of MOF catalysts (chemical unstability). This study indicated that the as-prepared Fe3O4@MC-Pd composite material shows great potential for using in a wide range of applications.

Raj, Raghu; Land, Kirkwood M.; Kumar, Vipan

doi: 10.1039/c5ra16361gpmid: N/A

The resistance of Plasmodium falciparum, the causative agent of malaria, against quinine and chloroquine along with the lack of malaria vaccines has encouraged the development of various synthetic strategies towards biologically active scaffolds. An emerging strategy in medicinal chemistry, termed molecular hybridization, involves the covalent fusion of two or more drugs, active compounds, and/or pharmacophoric units into a hybrid compound, with fascinating activities and multiple but not essentially simultaneous pharmacological targets. 4-Aminoquinolines are considered as promising antimalarials and 4-aminoquinoline hybridization is considered as an attractive and feasible approach for the development of new molecular frameworks for averting and delaying the emergence of drug resistance along with improved efficacy. The present review article describes the recent developments on the 4-aminoquinoline-hybridization towards the development of new antimalarials.

Patel, Deepak; Kurrey, Ganesh Ram; Shinde, Sandip S.; Kumar, Pradeep; Kim, Geon-Joong; Thakur, Santosh Singh

doi: 10.1039/c5ra12408epmid: N/A

The activation of inactive Jacobsen’s chiral salen Co(ii) (salen = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine) compound is attained by dinuclear chiral salen Co(iii)–OTf complex formation with yttrium triflate. The yttrium metal not only displays a promoting effect on electron transfer, but also assists in forming two stereocentres of a Lewis acid complex with Co(iii)–OTf. We found that the binuclear Co-complex significantly enhanced reactivity and enantioselectivity in the hydrolytic kinetic resolution of terminal epoxides compared to its analogous monomer and kinetic data are also consistent with these results.

Pang, Ran; Sun, Wenzhi; Fu, Jipeng; Li, Haifeng; Jia, Yonglei; Li, Da; Jiang, Lihong; Zhang, Su; Li, Chengyu

doi: 10.1039/c5ra14589apmid: N/A

In this article we synthesized a series of new reddish orange long-lasting phosphorescence phosphors by co-doping Li+ ions into Sm3+ activated α-Zn2P2O7, characterized their luminescence properties, and evaluated the effect of Li+ co-doping on both photoluminescence and Phosphorescence. The results showed that both the photoluminescence and Phosphorescence originated from characteristic reddish orange emissions of Sm3+ from its 4f–4f transitions of 4G5/2–6H5/2, 4G5/2–6H7/2 4G5/2–6H9/2 and 4G5/2–6H11/2. Besides markedly enhancing the photoluminescence intensity of Sm3+, the Li+ entering into the crystal lattice also promoted the long lasting phosphorescence performance via modifying the defect levels in the phosphors. The optimal long afterglow material was achieved when the Li+ concentration is 2 mol%. This phosphor shows bright reddish orange phosphorescence which could last for more than 3 hours in the dark. Four peaks appeared in its thermoluminescence curve, and the one at around 350 K was proved to be responsible for the occurrence of long lasting phosphorescence. The release of the captured electrons in the defect levels corresponding to this TL peak in room temperature to emission centers of Sm3+ underwent a tunneling process.

Dong, Yu; Cao, Ruixia; Li, Yingqi; Wang, Zhiqin; Li, Lin; Tian, Lu

doi: 10.1039/c5ra12383fpmid: N/A

An effective drug delivery system based on functionalized nanodiamond (ND) is constructed by layer-by-layer synthesis. Initially, ND is modified with PEG-diamine and conjugated with folate (FA) to obtain a ND-PEG-FA (NPF) nanocarrier. Then, doxorubicin (DOX) is physically attached to the NPF nanocarriers to prepare the drug system (ND-PEG-FA/DOX, NPFD), which exhibits excellent stability under neutral pH conditions, and releases large amounts of DOX in acidic extracellular fluids (pH 6.5 or pH 5.5). Relying on the role of folate and folate receptors, NPFD nanoparticles tend to discriminate between tumor cells and normal cells and enter the cells by clathrin-dependent and receptor-mediated endocytosis. Interestingly, an MTT assay found that the NPFD nanoparticles not only demonstrated a slow and sustained drug release profile, but also had tumor-targeted toxicity. This implies that the NPFD system is capable of targeted drug delivery and can act as a nanodrug with promising chemotherapeutic efficacy and safety.