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[Display omitted] • A coating with pH-dependent Cu2+ release was granted on the Ti. • The coating was composed of polydopamine and silk protein, exhibiting outstanding biocompatibility in vivo and in vitro. • While simulating a large gathering of bacteria (slightly acidic conditions), the coating could set free abundant Cu2+ to strongly kill bacteria and achieve self-defense. The implantation of medical devices is frequently accompanied by the invasion of bacteria, which may lead to implant failure. Therefore, an intelligent and responsive coating seems particularly essential in hindering implant-associated infections. Herein, a self-defensive antimicrobial coating, accompanied by silk fibroin as a valve, was successfully prepared on the titanium (Ti-Cu@SF) for pH-controlled release of Cu2+. The results showed that the layer could set free massive Cu2+ to strive against E. coli and S. aureus for self-defense when exposed to a slightly acidic condition. By contrary, a little Cu2+ was released in the physiological situation, which could avoid damage to the normal cells and showed excellent in vitro pH-dependent antibiosis. Besides, in vivo experiment confirmed that Ti-Cu@SF could work as an antibacterial material to kill S. aureus keenly and display negligible toxicity in vivo. Consequently, the design provided support for endowing the layer with outstanding biocompatibility and addressing the issue of bacterial infection during the implantation of Ti substrates. [ABSTRACT FROM AUTHOR]

Nowadays, the harm caused by the leakage of oil and dangerous organic solvents to the ecological environment and human health cannot be ignored, and effective treatment measures are urgently needed to alleviate the current situation. Therefore, the development of low-cost and efficient adsorbents is the key to solve the problem. In this paper, konjac glucomannan was used as flexible skeleton. Flexible aerogel based on an interpenetrating network of konjac glucomannan and reduced graphene oxide was prepared by two-step hydrothermal method. On this basis, the composite aerogel was superhydrophobically modified to improve its adsorption selectivity. A series of characterization results showed that the adsorbent had flexible three-dimensional porous structure, excellent mechanical properties, adsorption selectivity, recyclability and biodegradability. At the same time, the composite aerogel synthesized by a simple and environmentally friendly method could realize the continuous separation of oil and water by vacuum pump. It showed that its application in the field of high-efficiency oil–water separation had a broad prospect. [ABSTRACT FROM AUTHOR]

This study was aimed at evaluating the effect of oil extraction in spent coffee ground (SCG) on the properties of spent coffee ground-polypropylene composites. Coffee oil was removed from SCG by ultrasonication extraction. SCG and extracted spent coffee ground (ESCG) were used to reinforce the polypropylene (PP) in this research. Moisture uptakes, morphologies, mechanical properties, thermal properties, and accelerated aging test of composites were examined as a function of oil extraction. The results suggested that the extraction of coffee oil improved the water resistance of composites. The mechanical properties of spent coffee grounds-polypropylene composites (SCGPCs) were improved significantly after oil extraction, which suggested that the oil extraction was helpful to improve the interfacial adhesion and compatibility between filler and PP matrix. The moisture absorption of SCGPC showed a dramatic decrement after oil extraction. The results also revealed that the oil extraction improved the thermal property of composite. [ABSTRACT FROM AUTHOR]

Quaternary ammonium salts (QAS) have been widely applied in daily life because of their antibacterial properties. However the antibacterial effects of QAS cannot be effectively utilized due to the uncontrolled release. In this work, dodecyl dimethyl benzyl ammonium chloride (1227) and bromohexadecyl pyridine (CPB) were assembled on surfaces of graphene oxide (GO) through π–π interactions to form GO/QAS nanocomposites, i.e., GO-1227 and GO-CPB. In the comparison with pure CPB and 1227, GO-CPB and GO-1227 nanomaterials show biocompatible with reduced cytotoxicity. We found that GO could increase the antibacterial effect when the weak antibacterial agent was adopted. Remarkably, GO-1227 has exhibited stronger antimicrobial properties then GO-CPB, while GO-CPB has shown long-term slow-release antibacterial properties and CPB is facile to be loaded on GO surfaces. [ABSTRACT FROM AUTHOR]

In this study, three-dimensional (3D) flower-like nickel hydroxide (Ni(OH) 2 ) is decorated on one-dimensional fiber-like polyaniline (PANI) to obtain PANI/Ni(OH) 2 composite. Two-step hydrothermal method is used where PANI serves as crystal growth modifier of Ni(OH) 2 . By reducing the initial concentration of PANI, the polymorph of Ni(OH) 2 converts from β -to α -phase and the morphology of Ni(OH) 2 correspondingly changes from nanoplate to 3D flower-like, which significantly impacts the electrochemical activity of PANI/Ni(OH) 2 composite. Results show that fibrous PANI with high available surface area is expected to have many active sites for the deposition of nanoparticles. Besides, 3D flower-like Ni(OH) 2 , which can facilitate the transition for charge, contacts closely with PANI. Due to the good electrical conductivity and electrochemical activity of PANI with high proton doping level, the introduction of PANI can enhance the electrical conductivity and electrochemical performance of composite. Consequently, the PANI/Ni(OH) 2 electrode exhibits good electrochemical property, including high capacity, good rate capability and long cycle life. In addition, this work will provide a new concept for using polymer in dominating the structure, morphology and electrochemical property of electrode material. [ABSTRACT FROM AUTHOR]

Hexagonal nickel hydroxide/nickel decorated on reduced graphene oxide (rGO&Ni(OH) 2 –Ni) has been prepared via easy one-step chemical precipitation method and subsequent annealing treatment. The results show that the thermal stability of Ni(OH) 2 is enhanced by the incorporation of Ni. Besides, hexagonal Ni(OH) 2 –Ni nanoplate which can supply a short diffusion and migration pathway for electron and electrolyte ion contacts closely with the surface of rGO, resulting that the agglomeration of rGO is effectively prevented. Due to the good electrical conductivity of Ni, the incorporation of Ni can also improve the electrical conductivity of Ni(OH) 2 . More importantly, the Ni (111) plane is grown after annealing treatment, which plays a key role in Ni for further improving the electrochemical activity of composite. Consequently, the rGO&Ni(OH) 2 –Ni electrode exhibits high capacitance, high energy density, excellent rate capability, good cycle stability, etc. The advantages of easy preparation and excellent electrochemical performance imply the great potential application of rGO&Ni(OH) 2 –Ni in supercapacitors. Moreover, it is worthy noting that this work will offer a new approach for using metal nanoparticle in improving the electrochemical property of supercapacitor electrode material. [ABSTRACT FROM AUTHOR]