A novel strategy was developed to prepare nanospheres and vesicles as drug carriers. The drug-loaded pectin nanospheres and vesicles were fabricated in aqueous media containing Ca2+ and CO3(2-) ions under very mild conditions, which did not involve any surfactant. Through adjusting the preparation conditions, nanosized drug delivery systems with diverse morphologies, that is, nanospheres and vesicles, could be obtained. This technique could offer good control over the morphology and the size of nanospheres and vesicles. The morphologies of the aggregates were observed by environmental scanning electron microscopy and transmission electron microscopy. 5-Fluorouracil (5-FU), an antineoplastic drug, was encapsulated in the nanospheres and vesicles, and the in vitro drug release at different pH values was investigated. With the presence of Ca2+ and CO3(2-) ions in the pectin-based nanospheres/vesicles, the release of the low molecular weight drug could be effectively sustained from the highly hydrolyzed polysaccharide-based drug delivery systems.

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Abstract:In this paper, a novel method for preparing nanoparticle-polymer hybrid adsorbent was established. Laponite was dispersed in distilled water to form Laponite nanoparticles. These nanoparticles were pre-adsorbed by 2-acrylamido-2-methylpropane-sulfonic acid (AMPS) to improve their dispersion stability in chitosan solution. The nanoparticle-polymer hybrid adsorbent was prepared by copolymerization of chitosan, acrylamide, acrylic acid, AMPS, and Laponite nanoparticles. Four adsorbents were obtained and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller adsorption (BET). Additionally, the uptake capacities of Cu 2+ using different samples were studied. Compared to the adsorbent without chitosan and Laponite components, the maximum uptake of the hybrid adsorbent increased from 0.58 to 1.28 mmol·g −1 and the adsorption equilibrium time of it decreased from more than 75 min to less than 35 min, which indicated that the addition of chitosan and Laponite could greatly increase the adsorption rate and capacity of polymer adsorbent. The effects of different experimental parameters-such as initial pH, temperature, and equilibrium Cu 2+ concentration-on the adsorption capacities were studied. Desorption study indicated that this hybrid adsorbent was easy to be regenerated.

This study focuses on the preparation of thermoplastic polyurethane (TPU) nanocomposite using Vietnamese montmorillonite (MMT) as the reinforced phase. The MMT was previously modified by intercalating polyethylene oxide (PEO) and polyvinyl alcohol (PVA) molecules between the clay layers. X-ray diffraction (XRD) results of organoclays revealed that galleries of MMT were increased to 18.2 Å and 27 Å after their intercalation with PEO and PVA, respectively. Thermoplastic polyurethane (TPU) nanocomposites composed of 1, 3, 5, and 7%wt organoclays were synthesized. The result of XRD and transmission electron microscopic (TEM) analyses implied that the PEO modified MMT was well dispersed, at 3%wt, in polyurethane matrix. Fourier Transform Infrared Spectroscopic (FTIR) has confirmed this result by showing the hydrogenous interaction between the urethane linkage and OH group on the surface of silicate layer. Thermogravimetric (TG) showed that the organoclay samples also presented improved thermal stabilities. In addition, the effects of the organoclays on mechanical performance and water absorption of the PU nanocomposite were also investigated.

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We present a facile method for the fabrication of hematite nanocrystal-carbon cloth (FeO-CC) composite. Hierarchical manganite is chosen as the sacrificial precursor, that does not contribute to the component of final iron oxide but can be in situ dissolved by the acid produced from the Fe hydrolysis. This method effectively enhances the specific surface area and conductivity of hematite (FeO) by attaching FeO nanocrystals (around 5 nm) firmly on the surface of carbon fibers. The obtained FeO-CC can be directly used as a binder-free electrode for a supercapacitor. Interestingly, the composite electrode exhibits synergistic electrochemical capacitance (electrochemical double-layer capacitance and pseudo-capacitance). It manifests a very high areal capacitance of 1.66 F cm (1660 F g) at 2 mA cm and excellent cycling performance at large current densities (88.6% retention at 30 mA cm after 5000 cycles) in a three-electrode testing system, which is among the best performances reported in the literature. Importantly, when fabricated as a solid-state flexible symmetric supercapacitor it still shows a maximum energy density of 8.74 mW h cm and power density of 253.9 mW cm. Additionally, its good flexibility makes it suitable for portable devices.