Xibin Yi

Mesoporous amine-modified SiO2 aerogel: a potential CO2 sorbent

An amine-modified SiO2 aerogel (AMSA) was prepared using the sol–gel method and supercritical drying technology. CO2 adsorption tests were conducted under different conditions. High adsorption capacities were achieved in the presence of water vapor, with the highest CO2 adsorption capacity of 6.97 mmol/g-sorbent at 25 °C. A novel adsorption mechanism associated with the CO2 sorption process is proposed. The test results indicate that AMSA is a promising CO2 adsorbent.

Mechanically reinforced composite aerogel blocks by self-growing nanofibers

Here we report the preparation of mechanically reinforced composite aerogels using self-growing nanofibers. This approach was used to grow ZrOx nanofibers with a chemical imbalance in the SiO2 precursor solution and establish the property–structure relationship between the mechanical properties and self-growing nanofibers of ZrOx/SiO2 aerogels. As-synthesized ZrOx/SiO2 aerogels show a high compressive strength (9.68 MPa) and high BET surface area (827.22 m2 g−1). These novel ZrOx/SiO2 aerogels could be used as thermal isolates.

A facile process for preparation of polyaniline/polyacrylic acid composite electrochromism films

The polyaniline was synthesized by the emulsion polymerization and the polyaniline/polyacrylic acid (PANI/PAA) composite films were prepared through a layer-by-layer method. The porous PAA layer was used as a template for the deposition of PANI, and finally the composite film showed a network structure with large surface area and high porosity. The facile process for preparation of PANI/PAA composite films was good for large-scale production and application. The electrochromic performance of the PANI/PAA composite film was investigated by means of cyclic voltammogram, chronoamperometry and transmittance measurements. The composite film showed three typical redox couples, and the response time for reduction and oxidation was 90 and 102 ms, respectively. The PANI/PAA films also exhibited remarkable electrochromism ability with a reversible color change from yellow to purple and a transmittance change from 68 to 27% at 550 nm.

Improvement of mechanical strength of ultralight resorcinol–formaldehyde/silica aerogel by addition of zirconia

In the present work, RF/SiO2 aerogels reinforced by zirconia (ZrO2) were fabricated by a sol–gel process combined with N2-ethanol supercritical drying. The physical properties and microstructures of the aerogels were investigated by uniaxial compression, X-ray diffraction, N2 physico-adsorption, scanning electron microscopy, X-ray photoelectron spectroscopy, and infrared spectrum. The compressive strengths of the aerogels were improved obviously with the addition of ZrO2. The composite aerogels remained amorphous state even the percentage of ZrO2 reached up to 6.77 wt%. The pore sizes of the aerogels with various ZrO2 were hierarchical and the Brunauer-Emmett-Teller surface area increased distinctly with the increase of ZrO2. On the contrary, the aerogel particle sizes decreased as the increase of ZrO2. In our opinion, the enhanced compressive strengths derive from both of the varied pore structures and the decrease of the particle sizes.Graphical Abstract

Notice of Retraction Application of Central Composite Design to process optimization of Fe 3 O 4 /SiO 2 composited aerogel nanoparticle

The 2³ full-factorial Central Composite Design (CCD) and response surface methodology (RSM) was applied to explain the effect and interaction of three factors in the process of Fe₃O₄/SiO₂ nanoparticle: NaOH dosage, Fe₃O₄/SiO₂ ratio and Fe²⁺/Fe³⁺ ratio. For the CCD optimization purposes, the canonical parameters was employed where the predicted average size of the nanoparticles was 115.39 nm, and the experiment result was 120.3 nm; the predicted saturation magnetization of the nanoparticles was 80.89 emu/g, the experiment result was 84.09 emu/g at the optimum parameters of NaOH dosage 25 mg/ml, Fe₃O₄/SiO₂ ratio 0.3, Fe²⁺/Fe³⁺ ratio 0.5. In general, there is a good agreement between the experimental and the predicted parameters.

Preparation of PAA/WO3 composite films with enhanced electrochromism via layer-by-layer method

Abstract The polyacrylic acid/tungsten oxide (PAA/WO3) composite films with good electrochromic properties have been prepared by a layer-by-layer method. The porous PAA layers were used as a template for the deposition of WO3, and finally, the composite film showed a network structure with high porosity. The electrochromic performance of the PAA/WO3 composite film was investigated by means of cyclic voltammogram (CV), chronoamperometry (CA), and transmittance measurements. The PAA/WO3 film also exhibited a remarkable electrochromism ability with the reversible color change from transparent colorless to dark blue and the transmittance change from 83% to 24% at 620 nm. This research provided a cost-effective approach for the preparation of PAA/WO3 composite films with controllable microstructure and good electrochromic property.

Multifunctional Fluorescence/Magnetic Composite Microspheres for Cell Tracking and Drug Targeting Usage

A supermagnetic iron oxide (SPIO) microspheres is emerging as an ideal tool for cell tracking and drug targeting delivery. However, its low intracellular labeling efficiency has limited the potential usage. We have developed CdTe-incorporated CMCH/SiO2-coated core-shell composite microspheres, Fe3O4@SiO2@CMCH/CdTe (FSCC), with diameters of 210 nm, as a multifunctional magnetic vector that can efficiently orient targeted cells and visualize easily by UV. The multifunctional nanoparticles were injected into nude mice, and the potential usage as a dual modality imaging agent in vivo was demonstrated by MRI and UV light.