A bio-inspired strategy for the fabrication of superhyrophobic silicon carbide (SiC) ceramic foams (SCFs) using commercially available melamine foam (MF) as the template and vinyl-containing hyperbranched liquid polycarbosilane (VHPCS) as the binder was developed. The pre-oxidation process and crystallization degree during the sintering were monitored by Fourier transform infrared spectroscopy and X-ray diffraction. A plausible reaction was proposed and the thermogravimetry analysis results indicated that VHPCS was more suitable for the adhesive agent of SiC powders. By optimizing the mass ratio of VHPCS and SiC, a maximum compression strength of 1.25 MPa for SCFs was achieved with a low density of 0.514 g/cm 3 and only 6.72% of volume shrinkage. The obtained SCFs exhibited rapid power-free absorption towards highly viscous oils after a biomimetic surface modification with n-octadecylamine (ODA). It took only 22 s for the complete absorption of 200 μL ultra-high viscosity oil (5000 mPa s). A probable mechanism for the rapid absorption of viscous oil had been revealed and the decoration of low-surface-energy molecules together with the distinct porous structure were regarded as the critical factors.
As the number of people with diabetes continues to increase, the use of high-performing blood glucose testing devices for blood glucose management is critical. Therefore, a flexible micronedle sensor (MNs sensor) based on flexible micronedle array structure (MNs array) is proposed in this study, inspired by the ultra-fast water absorption characteristics of straw, which can be used to quickly, conveniently and noninvasculatively detect glucose concentration in human interstitium fluid (ISF). The MNs sensor is the composite of flexible MNs array and highly sensitive detection electrode. The MNs sensor has excellent mechanical properties, the maximum pressure is 69.2 N (4 times the average), the compressive strength is 88.13 MPa (1.88 times the average), and the fracture compression ratio is 194.7 %(3.36 times the average). These properties enable MN sensors to penetrate the stratum corneum in complete form while extracting ISF quickly and consistently. Meanwhile, the MN sensor has the highly sensitivity (1826.75nA mM −1 cm −2 , 4.72 times the average value). It has a wider detection range (1 mM-30 mM) and faster detection (30 s) than existing MN glucose detectors. In addition, the MN sensor has excellent anti-interference performance and can accurately detect glucose concentration in the case of multiple disturbances. This work lays a foundation for the development of a new painless, real-time monitoring and high accuracy blood glucose detection system.
Abdul Haleem,Jun Chen,Xiao-Xiao Guo,Shi-Chang Hou,Sheng-Qi Chen,Muhammad Siddiq,Wei-Dong He
Herein, for the first time, macro-porous hydrophobic cryogels of poly( iso- decyl acrylate- co -ethylene glycol dimethacrylate) P(IDA- co -EGDMA) have been successfully fabricated through γ -ray radiation-induced cryo-polymerization. This synthesis route is highly advantageous over the reported redox and UV-radiation routes for the synthesis of hydrophobic cryogels considering the high energy and the penetrating depth of γ -ray, which favours the fabrication of larger cryogels within shorter duration. The effects of radiation time, dose rate, amount of cross-linker, solvent type and solvent amount on the cryo-polymerization were studied in detail, which were based on the measurements of gel fraction and contact angle as well as the characterizations of Fourier transform infrared spectroscopy , thermal gravimetric analysis and scanning electron microscopic examination. The fabricated macro-porous cryogels were used as a sorbent for different organic solvents and oils. Using benzene as a common organic solvent, the absorption equilibrium was reached within only 60 s and the absorption capacity varied in the range of 16–20 g/g depending on the cryogel morphology and crosslinking density. As for the halogenated solvents, P(IDA- co -EGDMA) cryogels absorbed 25–29 g/g of chlorobenzene, bromobenzene, iodobenzene and tetrachloromethane. Those cryogels withstood high temperature (150 °C) deprived of any alteration in absorption capability and pore morphology. The cryogels reusability was also confirmed with keeping absorption capacity and cryogel mass up to 10 cycles.
危险品化学品经营许可证（带存储）