Interface functional groups play an essential role in regulating the electrical properties of bulk materials. In this work, we designed a novel strategy to explore a new way to enhance triboelectric performance by regulating the functional groups between nano-fillers and polymer matrix without obvious changes in the dielectric constant. The silica nanoparticles (SNPs) modified perfluoro-silane coupling agents (PFSCAs) with different chain lengths were added to the polyvinylidene difluoride to regulate the transferred charge density (TCD) of triboelectric nanogenerators (TENGs). When the doping concentration of perfluorodecyl modified SNPs is 2.25 wt.%, the nanocomposite film based TENG exhibits the maximum TCD of 166 µC/m² and power density of 3.12 W/m² which are 6 times and 39 times as big as those of pure polyvinylidene difluoride (PVDF) film. The charge accumulation and decay process show that interface functional groups dominate the performance of TENGs. Then, a Fermi level model is proposed and why the TCD could be regulated by the concentration of nanoparticles in bulk materials is explained. This work provides a new concept for understanding the performance of TENG independent dielectric constant and points out a new direction for enhancing TENG’s performance, since wealthy functional groups with selectivity are applicable.

In this work, we used nanocomposite saturable absorbers (SAs) in order to precisely design and modulate the process of compositing the light absorption by band gap engineering. Due to the higher absorption intensity of our MoS ₂ /MXene nanocomposite, we have successfully shortened the pulse duration (1.2 μ s) of SA with enhancing saturable absorption intensity (7.22 MW cm ⁻² ), and the ultra-fast fiber laser based on this nanocomposite SA has shown wider Q-switching stable range in the case of high pump power. This strategy can efficiently improve the performance of SA and shows the potential application prospect of nanocomposites in nonlinear optics.

Conductive polymers based sensors are potentially a powerful tool for detecting a variety of analytes in gas phase. However, the accuracy and reliability of such sensors are threatened by the humidity interference, which limits their use in demanding applications, e.g., air-quality monitoring and health care. Thus, there is an urgent need to suppress the response of conductive polymers to humidity. In this work, the surface of polyaniline (PANI) was modified by fatty acid to block the proton exchange between water molecules and PANI polymer chains and thus suppress the humidity response towards PANI based gas sensors. The results show that the humidity response suppression effect is depending on the chain length of surface modified alkyl acid. The long chain alkyl acid modified PANI sensors exhibit strong suppression of the humidity sensing response; while the short chain modified PANI sensors have weak suppression of the humidity sensing response. In specific, the Behenic acid modified PANI sensors have a concentration depend water vapor response as low as 0.008%/ppm, which is only 1/5 of the unmodified PANI sensors. This work might be a valuable example of the humid interferon suppression for other chemical sensors.