Surfaces and Interfaces最新文献

The effective treatment and high-value application of phosphogypsum (PG) are of critical importance for the sustainable development of this construction material. However, its poor water-resistance property has limited its application in the construction field. In order to expand the application potential of phosphorous-building gypsum (PBG) as a durable material, potassium hydroxide (KOH) and hydroxyl‑terminated polydimethylsiloxane (H-PDMS) were used as the activating agent, and the water-resistant modifying agent in this study, respectively, to develop a high-quality and water-resistant PBG product. In addition, molecular dynamics was used to reveal the modification mechanism of H-PDMS and the water-resistance mechanism of KOH activating PBG. The study results show that H-PDMS can significantly improve the water-resistance performance of PBG test blocks. KOH can increase the surface activity of PBG by introducing -OH radicals, promote the reaction between H-PDMS and PBG, and form a dense hydrophobic layer on PBG, thus effectively improving its water-resistance performance. The number of surface active -OH radicals in PBG, the clustering effect of H-PDMS, and impurities in PBG can all result in different experimental and simulation outcomes. Meanwhile, the electrostatic force is an important factor influencing the adsorption of water droplets on the surface of PBG, and the reaction of H-PDMS with PBG normally occurs between Si-O and S-O. This study has systematically interpreted the working mechanism of water-resistant PBG, presenting an important significance in the utilization of PG resources.

The development of flexible humidity sensors is essential for the advancement of wearable devices and electronic skin. However, the process of preparing these sensors is typically complex, and they often suffer from poor stability and a limited sensing range, which fails to meet the requirements for practical applications. Here, we prepared SnS₂ with nanoflower morphology by hydrothermal method, and successfully prepared a high-performance flexible humidity sensor with a high response range (20-95 %) by compositing it with B-TiO₂ nanoparticles with oxygen defects after sodium borohydride reduction and coating it on a PET flexible substrate. This sensor demonstrates an exceptional response (753.2 at 90 % RH) in high humidity environments and exhibits rapid response (13 s) and recovery times (19 s). Moreover, the sensor accurately detects human breathing patterns and frequencies, making it suitable for non-contact sensing applications. This research offers valuable insights into the simplified preparation and advancement of flexible humidity sensors.

A multiscale porous surface can significantly improve the osseointegration of biomedical implants, but it cannot be facilely achieved on the Poly-ether-ether-ketone (PEEK) surface. In this work, a macro-micro porous structure was prepared on the PEEK surface by ultrasound-assisted sulfonation. The surface morphologies, chemical compositions, functional groups, surface roughness, and wettability of the porous structures at different sulfonation times were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectrometer (FTIR), laser scanning confocal microscope (LSCM), and contact angle measurement, respectively. The results demonstrate that a macro-micro porous structure is formed on the PEEK surface, with macropore sizes ranging from 50 to 250 μm and micro-sized pore sizes ranging from 0.2 to 1.5 μm. Moreover, the results of in vitro cellular experiments demonstrate that the macro-micro porous structure can promote cell adhesion and proliferation of BMCSc. The formation mechanism of the multiscale porous structures has also been discussed. This novel approach may provide a simple and effective strategy for surface modification of PEEK to improve its mechanical and biological response.