An easy and efficient approach by using carboxyl functionalized CNTs (CNT-COOH) as nano reinforcement was reported to develop advanced thermosetting composite laminates. Benzoxazine containing cyano groups (BA-ph) grafted with CNTs (CNT-g-BA-ph), obtained from the in situ reaction of BA-ph and CNT-COOH, was used as polymer matrix and processed into glass fiber (GF)-reinforced laminates through hot-pressed technology. FTIR study confirmed that CNT-COOH was bonded to BA-ph matrices. The flexural strength and modulus increased from 450 MPa and 26.4 GPa in BA-ph laminate to 650 MPa and 28.4 GPa in CNT-g-BA-ph/GF composite, leading to 44 and 7.5% increase, respectively. The SEM image observation indicated that the CNT-COOH was distributed homogeneously in the matrix, and thus significantly eliminated the resin-rich regions and free volumes. Besides, the obtained composite laminates showed excellent thermal and thermal-oxidative stabilities with the onset degradation temperature up to 624 C in N 2 and 522 C in air. This study demonstrated that CNT-COOH grafted on thermosetting matrices through in situ reaction can lead to obvious mechanical and thermal increments, which provided a new and effective way to design and improve the properties of composite laminates.

Noble metal nanoparticles (NPs) modified electrodes have shown promising applications in the areas of catalysis, (electro)chemical analysis and biosensing due to their unique characters. In this paper, we introduced a so-called ligand exchange method to prepare self-assembly (SAM) electrode modified with noble metal nanoparticles. The noble metal nanoparticles protected by weakly adsorbed tetraoctylammonium bromide (TOAB) were synthesized firstly, then self-assembly (SAM) dithiol-modified Au electrode (Au-SH SAM ) was immersed into the solutions containing TOAB-protected nanoparticles. Due to the strong interaction between the dithiol groups on the electrode and noble metal nanoparticles, the weakly adsorbed TOAB on the surface of noble metal NPs were replaced by dithiol groups. As a result, the TOAB protected NPs were anchored on the Au-SH SAM template electrode surface by ligand exchange, obtaining noble metal NPs modified electrode with high quality and stability. By adjusting the soaking time, the coverage of nanoparticles on the Au-SH SAM electrode surface could be controlled. The morphology and distribution of noble metal NPs on Au-SH SAM surface was analysis by scanning tunneling microscope (STM), and their electrochemical property was studied by cyclic voltammetry (CV) in H 2 SO 4 solution. The approach is proved as a universal way to prepare noble metal NPs modified SAM electrode.

A high-temperature-resistant and high-performance hafnium oxide (HfO2) coating for aerospace engines was developed. HfO2 thin film coatings were prepared by chemical vapor deposition (CVD) at 1200, 1250, 1300, and 1350 °C, respectively. The crystal structure and surface morphology of the HfO2 thin films at different deposition temperatures were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The effect of deposition temperature on the mechanical properties of the HfO2 thin films was studied by means of the drainage method and nanoindentation. The results showed that the HfO2 coatings deposited at different deposition temperatures are monoclinic crystal structures, and the surface morphology changes from cellular particles to columnar particles, and finally, to a loose and porous layered structure. When the deposition temperature is 1300 °C, the density of the HfO2 film is the highest, 9.62 ± 0.03 g/cm3, and the hardness is the highest, 7.33 ± 0.04 GPa. A HfO2 coating with the best comprehensive mechanical properties was prepared by changing the deposition temperature, which provided an experimental basis for the application of a HfO2 coating in the aerospace field.

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