Fabrication of Biobased Hydrophobic Hybrid Cotton Fabrics Using Molecular Self-Assembly: Applications in the Development of Gas Sensor Fabrics

Self-Assembling Nanoarchitectonics of Twisted Nanofibers of Fluorescent Amphiphiles as Chemo-Resistive Sensor for Methanol Detection

The inhalation, ingestion, and body absorption of noxious gases lead to severe tissue damage, ophthalmological issues, and neurodegenerative disorders; death may even occur when recognized too late. In particular, methanol gas present in traces can cause blindness, non-reversible organ failure, and even death. Even though ample materials are available for the detection of methanol in other alcoholic analogs at ppm level, their scope is very limited because of the use of either toxic or expensive raw materials or tedious fabrication procedures. In this paper, we report on a simple synthesis of fluorescent amphiphiles achieved using a starting material derived from renewable resources, this material being methyl ricinoleate in good yields. The newly synthesized bio-based amphiphiles were prone to form a gel in a broad range of solvents. The morphology of the gel and the molecular-level interaction involved in the self-assembly process were thoroughly investigated. Rheological studies were carried out to probe the stability, thermal processability, and thixotropic behavior. In order to evaluate the potential application of the self-assembled gel in the field of sensors, we performed sensor measurements. Interestingly, the twisted fibers derived from the molecular assembly could be able to display a stable and selective response towards methanol. We believe that the bottom-up assembled system holds great promise in the environmental, healthcare, medicine, and biological fields.

Supramolecular Glycolipid-Based Hydro-/Organogels with Enzymatic Bioactive Release Ability by Tuning the Chain Length and Headgroup Size

Designing of supramolecular hydro-/organogels having desired properties, biocompatibility, and stimuli responsiveness is a challenging task. Herein, the gelation ability of amphiphilic glycolipid-based gelators in a wide range of solvents is explored. The structure-function relationship was established by varying the chain length and polar headgroup size of amphiphilic gelators. The prepared hydro-/organogels were characterized by employing several techniques such as differential scanning calorimetry (DSC), rheology, field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), etc. The thermal stability of hydro-/organogels increased with an increase in chain length. Rheological analysis depicted that variation in chain length and headgroup size of amphiphilic gelators significantly affected the gel strength and stability. The self-assembled morphology of hydro-/organogel samples revealed the compact entangled fibrillar network structures. After comparing the energy-minimized molecular length with the d-spacing value obtained by XRD, interdigitated bilayer packing in the gel network was established. The bioactive encapsulation and enzymatic release study of hydro-/organogels portrayed their potential application in the biomedical field. To our delight, glycolipid 16M (C16 chain length) formed a molecular hydrogel with injectable and thixotropic behaviors. High critical strain value, thixotropy, injectability, thermoreversibility, and faster bioactive release for the 16M-W hydrogel proved crucial to predict its future applications. Overall, glycolipid amphiphiles designed by upholding proper hydrophilic-lipophilic balance can form multifunctional supramolecular hydrogels with excellent implementation in the drug delivery system.

In situ restoration of soil ecological function in a coal gangue reclamation area after 10 years of elm/poplar phytoremediation

The soil ecological health risks and toxic effects of coal gangue accumulation were examined after 10 years of elm/poplar phytoremediation. The changes in soil enzyme activities, ionome metabolism, and microbial community structure were analyzed at shallow (5-15 cm), intermediate (25-35 cm), and deep (45-55 cm) soil depths. Soil acid phosphatase activity in the restoration area increased significantly by 4.36-7.18 fold (p < 0.05). Soil concentrations of the metal ions Cu, Pb, Ni, Co, Bi, U, and Th were significantly reduced, as were concentrations of the non-metallic element S. The repair effect was shallow > middle > deep. The soil community structure, determined by 16S diversity results, was changed significantly in the restoration area, and the abundance of microorganisms increased at shallow soil depths. Altererythrobacter and Sphingomonas species were at the center of the microbial weight network in the restoration area. Redundancy analysis (RDA) showed that S and Na are important driving forces for the microbial community distributions at shallow soil depths. The KEGG function prediction indicated enhancement of the microbial function of the middle depth soil layers in the restoration area. Overall, phytoremediation enhanced the biotransformation of soil phosphorus in the coal gangue restoration area, reduced the soil content of several harmful metal elements, significantly changed the structure and function of the microbial community, and improved the overall soil ecological environment.

Bimetallic Au@Pt Nanocrystal Sensitization Mesoporous α-Fe2O3 Hollow Nanocubes for Highly Sensitive and Rapid Detection of Fish Freshness at Low Temperature

In this work, we present a new metal oxide semiconductor gas sensor for detecting trimethylamine (TMA) by bimetal Au@Pt-modified α-Fe₂O₃ hollow nanocubes (NCs) as sensing materials. The structure and morphological characteristics of Au@Pt/α-Fe₂O₃ were evaluated through multiple analyses, and their gas-sensitive performance was investigated. Compared with the pristine α-Fe₂O₃ NC sensor, the sensor based on Au@Pt/α-Fe₂O₃ NCs exhibited faster response time (5 s) and higher response (R_a/R_g = 32) toward 100 ppm TMA gas at a lower temperature (150 °C). Furthermore, we also assessed the Au@Pt/α-Fe₂O₃ NC sensor for detecting the freshness of Larimichthys crocea which have been observed by headspace solid-phase microextraction and gas chromatography-mass spectrometry. The high performance of the Au@Pt/α-Fe₂O₃ NCs is attributed to the special hollow morphology with a high specific surface area (212.9 m²/g) and the synergistic effect of the Au@Pt bimetal. The Au@Pt/α-Fe₂O₃ sensor shows promising application prospects in estimating seafood freshness on the spot.