Zhixian Hao

A seeded synthetic strategy for uniform polymer and carbon nanospheres with tunable sizes for high performance electrochemical energy storage

We established a novel and facile strategy to synthesize uniform polymer and carbon nanospheres, the diameters of which can be precisely programmed between 35-105 and 30-90 nm, respectively, via time-controlled formation of colloidal seeds. The carbon nanospheres show promising prospects in high rate performance electrochemical energy storage.

Synthesis of carbon foams with a high compressive strength from arylacetylene

Carbon foams with high mechanical strength were prepared by polymerization of arylacetylene using sulfuric acid as a catalyst, pentane as a blowing agent and Tween 80 as a bubble stabilizer, followed by carbonization. Through controlling the preparation conditions such as the proportion of blowing agent, the concentration and volume of the catalyst, and the amount of the bubble stabilizer, carbon foams with good porous structure, smooth ligaments, and junctions without microcracks could be fabricated. The representative carbon foam possesses a high compressive strength of 25.8 MPa and a high strength/density ratio of 43.0 MPa/(g·cm−3), owing to a high char yield of the arylacetylene polymer, which is up to 86% after carbonization, and a good pore structure of the products.

Supramolecular core-shell nanosilica@liposome nanocapsules for drug delivery.

The fabrication of core-shell structural nanosilica@liposome nanocapsules as a drug delivery vehicle is reported. SiO(2) nanoparticles are encapsulated within liposomes by a W/O/W emulsion approach to form supramolecular assemblies with a core of colloidal particles enveloped by a lipid bilayer shell. A nanosilica core provides charge compensation and architectural support for the lipid bilayer, which significantly improves their physical stability. A preliminary application of these core-shell nanocapsules for hemoglobin (Hb) delivery is described. Through the H-bonding interaction between the hydroxyl groups on nanosilicas and the amino nitrogens of Hb, Hb-SiO(2) nanocomplexes in which the saturated adsorption amount of Hb on SiO(2) is 0.47 g g(-1) are coated with lipids to generate core-shell Hb-SiO(2)@liposome nanocapsules with mean diameters of 60-500 nm and Hb encapsulation efficiency of 48.4-87.9%. Hb-SiO(2)@liposome supramolecular nanovehicles create a mode of delivery that stabilizes the encapsulated Hb and achieves long-lasting release, thereby improving the efficacy of the drug. Compared with liposome-encapsulated Hb and Hb-loaded SiO(2) particles, such core-shell nanovehicles show substantially enhanced release performance of Hb in vitro. This finding opens up a new window of liposome-based formulations as drug delivery nanovehicles for widespread pharmaceutical applications.

A novel liposome-encapsulated hemoglobin/silica nanoparticle as an oxygen carrier

A novel liposome-encapsulated hemoglobin/silica nanoparticle (LEHSN) was fabricated by a water-in-oil-in-water (W/O/W) double emulsion approach. Bovine hemoglobin (Hb) was first adsorbed onto the surfaces of silica nanoparticles (SNs), and then the complex of Hb/SNs was encapsulated by liposome to form LEHSN which has a core-shell supramolecular structure. On the one hand, liposomes built a cell membrane-like environment for the controlled release of Hb. On the other hand, SNs which act as rigid core provide a supported framework for lecithin membrane, and enhance the stability of liposomes. In comparison with liposome-encapsulated Hb (LEH), LEHSN shows substantially enhanced stability and improved release property of Hb in vitro. This study highlights the potential of the novel LEHSN as an oxygen carrier for pharmaceutical applications.

Sol-Gel Synthesis of Alumina Using Inorganic Salt Precursor

Abstract A simple procedure based on gelatification, promoted by the ring-opening reaction of propylene oxide, was proposed for the synthesis of alumina, in which hydrated aluminium nitrate (Al(NO3)3·9H2O) was mixed with propylene oxide and gelated in ethanol solvent. After being dried and calcined under air atmosphere, a kind of amorphous alumina with a well-defined mesoporous structure was obtained. The samples were characterized by BET, SEM, FT-IR, and DTA. The results of liquid nitrogen adsorption indicated that two clear peaks appeared in the pore size distribution of each sample, whereas the larger pores were inkbottle-like. The average pore size of the alumina could be controlled by tuning the molar ratio of propylene oxide to aluminium nitrate over a range of pore diameters from 2.8 to 6.0 nm. The mechanism of the gelatification was finally proposed according to the characterizations. Both pH detection and FT-IR results demonstrated that propylene oxide indeed acted as an irreversible proton scavenger that induced inorganic aluminium ions to undergo hydrolysis and condensation to form the aluminium oxide framework.

Ag-nanoparticles on UF-microsphere as an ultrasensitive SERS substrate with unique features for rhodamine 6G detection

Urea and formaldehyde (UF) microsphere (MS) adsorbing Ag nanoparticles (NPs) was employed as a surface enhanced Raman scattering (SERS) substrate for rhodamine 6G (R6G) detection. The UF MSs and citrate-reduced Ag colloid supplying Ag NPs are synthesized separately and all the subsequent fabrication procedure is then implemented within 2 mL centrifuge tube. Influences of the composition and drying temperature of the UF MSs and the drying method and modification of AgNP/UFMS on the final SERS performance have first been reported. Excess formaldehyde useful in the formation of UF MSs again plays an important role in the SERS detection. Some interesting phenomena in the approach, such as swelling/deswelling of UF MSs and R6G diffusion within hydrophilic environment of UF MSs, are found to be of variable factors affecting the SERS performance. The substrate AgNP/UFMS confidently achieves a detection limit of 10(-13) M R6G and can be used as a simple and effective platform in the SERS spectroscopy.

Synthesis of Urea-Formaldehyde Resin Microspheres under Surfactant Conditions

The synthesis of urea-formaldehyde resin microspheres has been conducted with different sur- factants under the acidic conditions. Narrow size distributions of resin microspheres are obtained in the pres- ence of neutral surfactant Tween80 and cationic CTAB, while in that of anionic surfactant the resin product displays severe aggregation. After the prepolymer particles develop under conditions of neutral or cationic surfactant, the dispersity and spherical integrity of the microspheres improve significantly. Crystallinity of the microsphere products increases and the initial reaction rate slows in the presence of surfactant. In the case of neutral or cationic surfactant, the induction period of the prepolymer particles extends, the Raman absorption enhances, and the charge of the particles is positive, however, in the case of anion surfactant, the results are opposite to that described above. These results could be explained by the influence of surfactant amphiphilic and electrical properties on the nucleation and growth process of urea-formaldehyde resin mi-