ACS Applied Materials & Interfaces最新文献

Covalent organic frameworks (COFs) serve as an outstanding platform for heterogeneous photocatalysis. We synthesized two analogous pyrene-based two-dimensional COFs with π-conjugated networks, one linked by C═N bonds and the other by C═C bonds, through Schiff base and Knoevenagel condensation reactions, respectively. We investigated the impact of these linkages on the photocatalytic activity of these COFs, using visible-light-mediated thioesterification as a model reaction. It was found that the olefin-linkage COF outperformed the imine-linkage COF as a photocatalyst. The developed protocol demonstrated a broad substrate scope, including 35 diverse carboxylic acids, 14 drug molecules, and several disulfide coupling partners, achieving up to a 95% yield of thioesters. The practical utility of this strategy is further demonstrated by its successful application in gram-scale reactions. The photocatalyst is robust and was successfully reused for multiple cycles without any loss of catalytic activity. The COF backbone facilitated enhanced electron transfer upon light irradiation, enabling the cross-coupling of carboxylic acid and disulfide through a reductive photocatalytic cycle.

The quality of organic-inorganic hybrid perovskite films directly affects the application prospect of perovskite solar cells (PSCs), where organic and inorganic cations are the core elements that affect the quality of the perovskite. The additive strategy has been widely used to passivate cation-related defects in perovskite films. Here, the perovskite precursor solution introduced 5-bromopyridine-3-sulfonic acid (BOH) with a potential all-cation passivation function. The experimental results verified that the N atom on pyridine in the BOH molecular structure passivated the defects in perovskite by binding with undercoordination Pb²⁺, and the sulfonic acid group inhibited nonradiative recombination through their interactions with FA⁺ and Pb²⁺, improving perovskite grain size and crystallinity, and enhancing film quality. Thanks to the all-cationic targeted anchoring effect of BOH, the efficiency of the BOH-treated device upgraded from 22.32 to 24.33%. Importantly, PSCs with BOH showed excellent stability after exposure to 25% humidity for 1200 h at room temperature.

Magnetic hyperthermia (MH) has emerged as a promising technology with diverse applications in medical and technological fields, leveraging the remote induction of temperature elevation through an alternating magnetic field. While Fe₃O₄ nanoparticles with an average size around 12-25 nm are commonly employed in MH systems, this study introduces a strategy to produce smaller particles (less than or equal to 10 nm) with enhanced heating efficiency, as measured by specific power absorption (SPA). We conducted an exhaustive and detailed investigation into the morphological and magnetic properties of Co_xFe_3-xO₄ nanoparticles, aiming to optimize their MH response. By varying the Co content, we successfully tuned the effective magnetic anisotropy while maintaining saturation magnetization nearly constant. The MH analysis indicates that these nanoparticles predominantly heat through the Néel mechanism, demonstrating robust reproducibility across different concentrations, viscosity mediums, and ac field conditions. Notably, we identified an optimal anisotropy or Co concentration that maximizes SPA, crucial for developing magnetic systems requiring particles with specific sizes. This work contributes to advancing the understanding and application of MH, particularly in tailoring nanoparticle properties for targeted and efficient heat generation in various contexts.

The atrazine nanodelivery system, composed of poly(ε-caprolactone) (PCL+ATZ) nanocapsules (NCs), has demonstrated efficient delivery of the active ingredient to target plants in previous studies, leading to greater herbicide effectiveness than conventional formulations. Established nanosystems can be enhanced or modified to generate new biological activity patterns. Therefore, this study aimed to evaluate the effect of chitosan coating of PCL+ATZ NCs on herbicidal activity and interaction mechanisms with Bidens pilosa plants. Chitosan-coated NCs (PCL/CS+ATZ) were synthesized and characterized for size, zeta potential, polydispersity, and encapsulation efficiency. Herbicidal efficiency was assessed in postemergence greenhouse trials, comparing the effects of PCL/CS+ATZ NCs (coated), PCL+ATZ NCs (uncoated), and conventional atrazine (ATZ) on photosystem II (PSII) activity and weed control. Using a hydroponic system, we evaluated the root absorption and shoot translocation of fluorescently labeled NCs. PCL/CS+ATZ presented a positive zeta potential (25 mV), a size of 200 nm, and an efficiency of atrazine encapsulation higher than 90%. The postemergent herbicidal activity assay showed an efficiency gain of PSII activity inhibition of up to 58% compared to ATZ and PCL+ATZ at 96 h postapplication. The evaluation of weed control 14 days after application ratified the positive effect of chitosan coating on herbicidal activity, as the application of PCL/CS+ATZ at 1000 g of a.i. ha^-1 resulted in better control than ATZ at 2000 g of a.i. ha^-1 and PCL+ATZ at 1000 g of a.i. ha^-1. In the hydroponic experiment, chitosan-coated NCs labeled with a fluorescent probe accumulated in the root cortex, with a small quantity reaching the vascular cylinder and leaves up to 72 h after exposure. This behavior resulted in lower leaf atrazine levels and PSII inhibition than ATZ. In summary, chitosan coating of nanoatrazine improved the herbicidal activity against B. pilosa plants when applied to the leaves but negatively affected the root-to-shoot translocation of the herbicide. This study opens avenues for further investigations to improve and modify established nanosystems, paving the way for developing novel biological activity patterns.

The successful realization of thin film composite (TFC) organic solvent nanofiltration (OSN) membranes with high permeability and small solute selectivity for solute-solute separation to purify drugs in complex solution environments remains challenging in the pharmaceutical industry. Here, we present the preparation of high cross-linked TFC OSN membranes via interfacial polymerization (IP) utilizing phlorotannin, a plant-derived biomass phenolic compound, as a promising aqueous phase monomer. Benefiting from the presence of multiple cross-linking sites and twisted rigid structure in phlorotannin, nanofiltration membranes with excellent molecular selectivity and solvent permeability were successfully fabricated. This allowed for straightforward separation and purification of active pharmaceutical ingredients from intermediates. The membranes demonstrated remarkable stability over extended periods of operation and adaptability to a diverse array of solvent environments, making them a highly promising option for use in fine chemicals, biopharmaceuticals, and other fields.

A vapor-phase ZIF-8 MOF deposition procedure for seamless high-aspect-ratio interconnect gap fill has been developed with a short process time (15 min) at a 160 °C process temperature. This is the most rapid documented vapor technique to produce a MOF film and is made possible by a higher process temperature and a low background H₂O environment. The process consists of ALD of a thin (<5 nm) ZnO film followed by conversion to ZIF-8 in an organic linker (ALD + soak cycle). This method exhibited complete ZnO to MOF conversion, as well as MOFs with low-k (k ∼ 2.6). Dielectric gap fill was investigated utilizing patterned samples with widths ranging from 40 to 400 nm. Both high aspect ratio gap fill and multiple aspect ratio gap fills were shown with no residual ZnO. The MOF gap-fill process could be attributed to the reflow behavior of 2-methylimidazole-ZnO reaction intermediates or nascent product. The MOF was found to be stable at 400 °C under vacuum (1 × 10^-2 Torr), which is comparable to other low-k dielectrics. Fluorine plasma etch resistance was tested for the ZIF-8 MOF in comparison to bare Si, SiCOH, and SiO₂; the MOF was proven to be the best in resisting plasma etch. This work demonstrated that ALD + soak cycle conversion low-k ZIF-8 MOF films have the potential to be a plasma-free vapor-phase seamless gap fill for high aspect ratio features to be employed in logic and memory device fabrication, as well as three-dimensional heterogeneous integration (3DHI).