Synthesis and characterization of a novel antibacterial material containing poly(sulfobetaine) using reverse atom transfer radical polymerizationChu, Xiaohong; Zhang, Ming; Zhou, Ninglin; Wu, Fan; Sun, Baohong; Shen, Jian
doi: 10.1039/c8ra05793apmid: 35548141
A novel antibacterial agent was synthesized using 2-(dimethylamino)ethyl methacrylate (DM) and sodium 3-chloro-2-hydroxypropane sulfonate (CHPS). It was characterized by Fourier transform infrared spectroscopy (FTIR), NMR Spectroscopy (1H NMR), and X-ray photoelectron spectroscopy (XPS). This new agent DMCHPS was then grafted onto a polyurethane (PU) substrate via surface-initiated reverse atom transfer radical polymerization (SI-RATRP). The modified PU was characterized by FTIR and XPS. The hydrophilic properties of the PU surface before and after the incorporation of DMCHPS were determined by static contact angle (SCA) measurements. The results showed that the hydrophilicity of the PU surface after the modification was remarkably improved. MIC tests and bacterial adhesion confirmed that modified PU has good antibacterial properties. Protein adsorption experiments show that the material has a certain ability to resist pollution. Furthermore, the high survival rate of HEK293 human embryonic kidney cells shows that the modified PU has a potential use as a medicinal material.
Effect of metal doping on the visible light absorption, electronic structure and mechanical properties of non-toxic metal halide CsGeCl3Rahaman, Md. Zahidur; Akther Hossain, A. K. M.
doi: 10.1039/c8ra06374epmid: 35548143
Non-toxic metal halide perovskites have become forefront for commercialization of the perovskite solar cells and optoelectronic devices. In the present study, for the first time we show that particular metal doping in CsGeCl3 halide can considerably enhance the absorbance both in the visible and ultraviolet light energy range. We have carried out DFT based first principles calculations on Mn-doped and Ni-doped CsGeCl3 halide. We investigate the detailed structural, optical, electronic and mechanical properties of all the doped compositions theoretically. The study of the optical properties shows that the absorption edge of both Ni and Mn-doped CsGeCl3 is shifted toward the low energy region (red shift) relative to the pristine one. An additional peak is observed for both doped profiles in the visible light energy region. The study of the mechanical properties demonstrates that both the doped samples are mechanically stable and ductile as the pristine CsGeCl3. The study of the electronic properties shows that the excitation of photoelectrons is easier due to the formation of intermediate states in Mn-doped CsGeCl3. As a result Mn-doped CsGeCl3 exhibits higher absorptivity in the visible region than the Ni-doped counterpart. A combinational analysis indicates that CsGe1−xMnxCl3 is the best lead free candidate among the inorganic perovskite materials for solar cell and optoelectronic applications.
A ZnO/rice husk-based hollow carbonaceous nanosphere composite as an anode for high-performance lithium-ion batteriesLi, Yi; Gao, Yan; Qi, Hui; Yu, Kaifeng; Liang, Ce
doi: 10.1039/c8ra06169fpmid: 35548154
ZnO is considered as a substitute for the next generation of lithium ion battery anode materials because of its high volumetric energy density and abundant resources. In this work, we fabricate a new material that has nanorod-like ZnO distributed in a disorderly fashion on the surface of a rice husk-derived carbon skeleton. Rice husk as a carbon source is suitable for easing the pressure on the environment and improving the utilization of agricultural residues. Its unique interconnected hollow nanosphere structured skeleton provides better support for ZnO loading and electron transport. The ZnO/rice husk-based carbonaceous nanosphere composite samples were characterised by XRD, Raman, SEM and TEM. When used as an anode for lithium-ion batteries, the material exhibited promising Li storage properties and a high specific charge capacity of 920 mA h g−1 at 0.2C after 100 cycles.
Effect of phosphorus content on mechanical properties of polymeric nickel composite materials with a diamond-structure microlatticeZhao, Yungang; Wei, Fang; Zhao, Xinqing; Yang, Qinglin; Guo, Lin; Jiang, Lei
doi: 10.1039/c8ra04695fpmid: 35548161
Periodical and ordered polymer–nickel-coated composite materials with a diamond-structure microlattice and various contents of phosphorus (4.10 wt%, 8.01 wt%, 12.25 wt%, 16.08 wt%, 20.21 wt%) were fabricated via electroless nickel–phosphorus (Ni–P) coating onto diamond-structured polymeric templates using a 3D printing stereo lithography apparatus. With the increase in P content, the crystal morphology transfers from crystal to non-crystal. By controlling identical 1.0 μm-thickness of 5 different content coatings onto templates, the properties of 5 different microlattice composites were tested by uniaxial compression. To confirm the thickness and P content, several mathematical models were developed to direct the subsequent experiments and all theoretical predictions are in agreement with factual characterization. The composite with 8.01 wt% phosphorus content and density of 240.4 kg m−3 performs best, with the maximum compressive strength reaches 1.08 MPa, which is 2.1 times higher than that of polymer templates.
In situ approach of cementite nanoparticles encapsulated with nitrogen-doped graphitic shells as anode nanomaterials for Li-ion and Na-ion batteriesLi, Na Na; Sheng, Zhao Min; Tian, Hao Liang; Chang, Cheng Kang; Jia, Run Ping; Han, Sheng
doi: 10.1039/c8ra05544kpmid: 35548136
Novel Fe3C nanoparticles encapsulated with nitrogen-doped graphitic shells were synthesized by floating catalytic pyrolysis. Due to the short synthesis time and controllable pyrolytic temperature, the diameters of Fe3C core nanoparticles ranged from 5 to 15 nm (Fe3C@NGS900 prepared at 900 °C) and the average thickness of N-doped graphitic shells was ∼1.2 nm, leading to their high electrochemical performance: specific capacity of 1300 mA h g−1 at current density 0.2 A g−1, outstanding rate capability of 939 mA h g−1 at 3 A g−1, improved initial coulombic efficiency (Fe3C@NGS900: 72.1% vs. NGS900 (pure graphitic shells): 52%) for lithium ion batteries (LIBs), and impressive long-term cycle performance (1399 mA h g−1 maintained at 3 A g−1 after 500 cycles for LIBs; 214 mA h g−1 maintained at 1 A g−1 after 500 cycles for sodium ion batteries).
Synthesis, structure, and luminescence characteristics of far-red emitting Mn4+-activated LaScO3 perovskite phosphors for plant growthSun, Liangling; Devakumar, Balaji; Guo, Heng; Liang, Jia; Li, Bin; Wang, Shaoying; Sun, Qi; Huang, Xiaoyong
doi: 10.1039/c8ra06629apmid: 35548111
Far-red emitting phosphors LaScO3:Mn4+ were successfully synthesized via a high-temperature solid-state reaction method. The X-ray powder diffraction confirmed that the pure-phase LaScO3:Mn4+ phosphors had formed. Under 398 nm excitation, the LaScO3:Mn4+ phosphors emitted far red light within the range of 650–800 nm peaking at 703 nm (14 225 cm−1) due to the 2Eg → 4A2g transition, which was close to the spectral absorption center of phytochrome PFR located at around 730 nm. The optimal doping concentration and luminescence concentration quenching mechanism of LaScO3:Mn4+ phosphors was found to be 0.001 and electric dipole–dipole interaction, respectively. And the CIE chromaticity coordinates of the LaScO3:0.001Mn4+ phosphor were (0.7324, 0.2676). The decay lifetimes of the LaScO3:Mn4+ phosphors gradually decreased from 0.149 to 0.126 ms when the Mn4+ doping concentration increased from 0.05 to 0.9 mol%. Crystal field analysis showed that the Mn4+ ions experienced a strong crystal field in the LaScO3 host. The research conducted on the LaScO3:Mn4+ phosphors illustrated their potential application in plant lighting to control or regulate plant growth.
Numerical simulations of wall contact angle effects on droplet size during step emulsificationWang, Meng; Kong, Chuang; Liang, Qisen; Zhao, Jianxiang; Wen, Maolin; Xu, Zhongbin; Ruan, Xiaodong
doi: 10.1039/c8ra06837bpmid: 35548132
Terrace-based microfluidic devices are currently used to prepare highly monodisperse micro-droplets. Droplets are generated due to the spontaneous pressure drop induced by the Laplace pressure, and so the flow rate of a dispersed phase has little effect on droplet size. As a result, control over the droplet is limited once a step emulsification device has been fabricated. In this work, a terrace model was established to study the effect of the wall contact angle on droplet size based on computational fluid dynamics simulations. The results for contact angles from 140° to 180° show that a lower contact angle induces wall-wetting, increasing the droplet size. The Laplace pressure equations for droplet generation were determined based on combining pressure change curves with theoretical analyses, to provide a theoretical basis for controlling and handling droplets generated through step emulsification.
Enhanced photocatalytic activity and ultra-sensitive benzaldehyde sensing performance of a SnO2·ZnO·TiO2 nanomaterialSubhan, Md Abdus; Chandra Saha, Pallab; Sumon, Shamim Ahmed; Ahmed, Jahir; Asiri, Abdullah M.; Rahman, Mohammed M.; Al-Mamun, Mohammad
doi: 10.1039/c8ra05182hpmid: 35548107
The synthesis of a ternary SnO2·ZnO·TiO2 nanomaterial (NM) by a simple co-precipitation method and its potential applications as an efficient photocatalyst and chemical sensor have been reported. The synthesized nanomaterial was fully characterized by XRD, SEM, EDS, XPS, FTIR, AFM and photoluminescence studies. This nanomaterial exhibited enhanced efficiency in photo-catalysis of Methyl Violet 6b (MV) dye degradation. The observed photocatalyst efficiency of the SnO2·ZnO·TiO2 nanomaterial was 100% under UV light at pH 9. Moreover, it lost around 12% efficiency over five reuses. The PL properties with changing excitation energy were also reported. Glassy carbon electrode (GCE) was modified with the SnO2·ZnO·TiO2 nanomaterial by an efficient electrochemical technique to develop a chemical sensor for selective benzaldehyde. Hazardous benzaldehyde was carefully chosen as a target analyte by a selectivity study; it displays a rapid response towards the SnO2·ZnO·TiO2/Nafion/GCE sensor probe in electrochemical sensing. It also shows superb sensitivity, an ultra-low detection limit, long-term stability, and very good repeatability and reproducibility. In this study, a linear calibration plot was obtained for 0.1 nM to 1.0 mM aqueous benzaldehyde solutions, with a sensitivity value of 4.35 nA μM−1 cm−2 and an exceptionally low detection limit (LOD) of 3.2 ± 0.1 pM (S/N = 3). Hence, a chemical sensor modified with SnO2·ZnO·TiO2/GCE may be a promising sensor in the determination of toxic chemicals in the environmental and healthcare fields.
Facile and template-free solvothermal synthesis of mesoporous/macroporous metal–organic framework nanosheetsZhang, Boce; Luo, Yaguang; Kanyuck, Kelsey; Saenz, Natalie; Reed, Kevin; Zavalij, Peter; Mowery, Joseph; Bauchan, Gary
doi: 10.1039/c8ra06576dpmid: 35548163
A facile and template-free solvothermal method was developed as a bottom-up approach to synthesize mesoporous/macroporous MOF nanosheets in a simple and scalable way. It was found that starting coordination complexes of different copper(ii)-ligand compounds mediated the controlled growth and morphology of MOF crystals. By controlling the size and shape of the MOF crystals, the possibility to adjust and tailor the structure and performances of the assemblies was demonstrated. This work provides a bottom-up approach to synthesize MOF films and nanosheets in a simple and scalable way, which may have potential in energy and biomedical applications.
Controlled hydrothermal temperature provides tunable permittivity and an improved electromagnetic absorption performance of reduced graphene oxideXia, Yilu; Wang, Jiankun; Chen, Chaochan; Huo, Da; Wen, Yue; Wang, Wenyue; Sun, Mengxiao; Xu, Chang; Xie, Aming; Wu, Fan; Feng, Zhangqi
doi: 10.1039/c8ra05843apmid: 35548124
Reduced graphene oxide (RGO) has been prepared by a hydrothermal reduction method to explore the effects of reaction temperature on its permittivity and electromagnetic absorption (EA) performance. This study shows that by controlling the oxygen functional groups on the RGO surface it is also possible to obtain an ideal EA performance without any other decorated nanomaterials.