Effects of dissolved organic matter, pH and nutrient on ciprofloxacin bioaccumulation and toxicity in duckweed.

Water pollution induced by antibiotics has garnered considerable concern, necessitating urgent and effective removal methods. This study focused on exploring ciprofloxacin (CIP) removal by duckweed and assessing CIP bioaccumulation and toxic effects within duckweed under varying dissolved organic matter categories, pH levels, and nutrient (nitrogen (N) and phosphorus (P)) levels. The results revealed the proficient and rapid elimination of CIP from water by duckweed, resulting in 86.17 % to 92.82 % removal efficiency at the end of the 7-day experiment. Across all exposure groups, varying degrees of CIP bioaccumulation in duckweed were evident, with uptake established as a primary pathway for CIP elimination within this plant. Additionally, five CIP metabolites were identified in duckweed tissues. Interestingly, the presence of humic acid (HA) and fulvic acid (FA) reduced CIP absorption by duckweed, with FA yielding a more pronounced impact. Optimal CIP removal was recorded at a pH of 7.5, while duckweed displayed heightened physiological stress induced by CIP at pH 8.5. Although the influence of N and P concentrations on CIP removal by duckweed was modest, excessive N and P levels intensified the physiological strain of CIP on duckweed.

Reconfigurable Touch Panel Based on a Conductive Thixotropic Supramolecular Hydrogel.

Touch panels based on ionic conductive hydrogels perform excellent flexibility and biocompatibility, becoming promising candidates for the next-generation human-machine interface. However, these ionic hydrogels are usually composed of cross-linked polymeric networks that are difficult to be recycled or reconfigured, resulting in environmental issues. Herein, we designed a lithium ion-triggered gelation strategy to provide a conductive molecular hydrogel with thixotropy, which can be mechanically recycled or reconfigured at room temperature. In this hydrogel, lithium ions function as ionic bridges to construct supramolecular nanoassemblies and charge carriers to impart ionic conductivity. With polymer additives, the mechanical accommodability of the hydrogel was improved to meet the requirements of the daily use of touch panels. When this molecular hydrogel was fabricated into a surface capacitive touch panel, real-time sensing and reliable touch locating abilities were achieved. Remarkably, this touch panel can be reconfigured into 1D, 2D, and 3D device structures by a simple stirring-remolding method under ambient conditions. This work brings new insight into enriching the functionalities of hydrogel-based ionotronics with a supramolecular approach.

High-strain sensitive zwitterionic hydrogels with swelling-resistant and controllable rehydration for sustainable wearable sensor.

The irrecoverability of mechanical strength, conductivity and other properties after dehydration, has severely restricted the practical applications of hydrogels. To address this issue, here we report a P(AA-SMA-SBMA) zwitterionic copolymer-based hydrogel with anti-swelling, high mechanical property and reusability after dehydration/hydration process by polymerization of acrylic acid (AA), octadecyl methacrylate (SMA) and sulfobetaine methacrylate (SBMA). The structures of the original hydrogels and that after dehydration/hydration cycles were characterized by SAXS, SEM, Raman, FT-IR, XRD, DSC and rheology, etc. It was proved that both the macroscopic properties and the micro-structures were maintained after several dehydration/hydration cycles, owing to the synergistic effects of hydrophobic and super-hydrophilic interaction in the 3D network structure. Moreover, the fabricated hydrogels possess high strain sensitivity which is applied to monitor both junction motion and subtle movement like breathing and pulse. In addition, such sensitivity of the hydrogel sensors could be maintained after several dehydration/hydration cycles or even sinking in water for over two months. This work provides a type of hydrogel material with stable properties after dehydration process by regulating hydrophobic and hydrophilic interaction, which is beneficial for the life-time and sustainability of hydrogel devises.