Incorporating amino acids functionalized graphene oxide nanosheets into Pebax membranes for CO2 separation

Transgenerational reproductive toxicity induced by carboxyl and amino charged microplastics at environmental concentrations in Caenorhabditis elegans: Involvement of histone methylation

Microplastics, recognized as emerging contaminants, are commonly observed to be charged in the environment, potentially exerting toxic effects on various organisms. However, the transgenerational reproductive toxicity and underlying mechanisms of polystyrene (PS), particularly carboxyl-modified PS (PS-COOH) and amino-modified PS (PS-NH2), remain largely unexplored. In this study, the parental generation (P0) of Caenorhabditis elegans was subjected to environmental concentrations (0.1-100 μg/L) of PS, PS-COOH, and PS-NH2, with subsequent generations (F1-F4) cultured under normal conditions. Exposure to PS-NH2 at concentrations of 10-100 μg/L exhibited more pronounced reproductive toxicity compared to PS or PS-COOH, resulting in decreased brood size, egg ejection rate, number of fertilized eggs, and cell corpses per gonad. Similarly, maternal exposure to 100 μg/L of PS-NH2 induced more severe transgenerational reproductive effects in C. elegans. Significant increases in H3 on lysine 4 dimethylation (H3K4me2) and H3 on lysine 9 trimethylation (H3K9me3) levels were observed in the subsequent generation, concurrent with the transgenerational upregulation of set-30 and met-2 following parental exposure to PS, PS-COOH, and PS-NH2. Correlation analyses revealed significant associations between the expression of these genes with the reproductive ability. Molecular docking studies suggested that PS-NH2 exhibited higher affinity for SET-30 and MET-2. Further analysis demonstrated that transgenerational effects on reproduction were absent in set-30(gk315) and met-2(n4256) mutants, highlighting the pivotal role of set-30 and met-2 in mediating the transgenerational effect. This study provides novel insights into the environmental risks associated with negatively and positively charged microplastics.

Micro and Nanoporous Membrane Platforms for Carbon Neutrality: Membrane Gas Separation Prospects

Recently, carbon neutrality has been promoted as a potentially practical solution to global CO2 emissions and increasing energy-consumption challenges. Many attempts have been made to remove CO2 from the environment to address climate change and rising sea levels owing to anthropogenic CO2 emissions. Herein, membrane technology is proposed as a suitable solution for carbon neutrality. This review aims to comprehensively evaluate the currently available scientific research on membranes for carbon capture, focusing on innovative microporous material membranes used for CO2 separation and considering their material, chemical, and physical characteristics and permeability factors. Membranes from such materials comprise metal-organic frameworks, zeolites, silica, porous organic frameworks, and microporous polymers. The critical obstacles related to membrane design, growth, and CO2 capture and usage processes are summarized to establish novel membranes and strategies and accelerate their scaleup.

Improved Through-Plane Thermal Conductivity of Poly(dimethylsiloxane)Composites through the Formation of 3D Filler Foam Using Freeze-Casting and Annealing Processes

The configuration of a continuous and oriented thermal pathway is essential for efficient heat dissipation in the oriented direction. Three-dimensional (3D) conductive filler structures provide a suitable approach for constructing continuous thermal pathways in polymer-based composites. The aluminum nitride/reduced graphene oxide/poly(dimethylsiloxane) (AlN/rGO/PDMS) composite material is made with a 3D foam structure and focuses on reducing GO and forming foam via polyvinyl alcohol (PVA). We analyze the successful fabrication of hybrid fillers and composites using various methods. The fabricated composite with a 3D network filler foam achieves a through-plane thermal conductivity of 1.43 W/mK and achieves 752% higher thermal conductivity compared to pure PDMS, which is superior to composites without 3D foam. The continuous 3D filler structure via freeze-drying and annealing processes provides efficient thermal dissipation in the through-plane direction pathway, which is critical for enhancing thermal conductivity. Therefore, this work produces a polymer composite material with improved thermal conductivity through various processes.

Graphene based composite membranes for environmental toxicology remediation, critical approach towards environmental management

Graphene-based composite membranes, as laminated, stacked, and assembled architectures of graphene, have surpassed other conventional membranes with their advanced and preeminent structural specialization and potential use in a wide range of sustainable and environmental applications. The characteristic membrane features such as distinct laminar morphology, tailored physicochemical properties, as well as extraordinary molecular properties have fascinated scientists. Due to remarkable mechanical properties, these membranes can be easily fabricated. Recent progress has been achieved by graphene and its derivatives-based membranes to purify water and gases for environmental remediation. This review explained the latest and groundbreaking advances in chemical design, fabrication, and application of graphene-based membranes. Special attention is paid to the recent developments on graphene-based composites into membranes with various forms: free-standing, layered, and graphene-based nanocomposite membranes. Furthermore, a unique approach on environmental management with as-fabricated membranes is provided by discussing the effect of physicochemical properties. Consequently, their full-scale use for environmental management, water purification, gas purification, and biological treatments will pave the way for their promising features and realize their future prospects.

Preparation of Pebax 1657/MAF-7 Mixed Matrix Membranes with Enhanced CO2/N2 Separation by Active Site of Triazole Ligand

Fillers play a critical role in the performance of mixed matrix membranes (MMMs). Microporous metal azolate frameworks (MAFs) are a subclass material of metal-organic frameworks (MOFs). Due to the uncoordinated nitrogen of the organic ligands, MAF-7 (SOD-[Zn(mtz)₂], Hmtz = 3-methyl-1,2,4-triazole, window: d = 0.34 nm) shows excellent CO₂ adsorption performance. In this work, Pebax 1657/MAF-7 MMMs were prepared by a sample solution casting method with MAF-7 particles as fillers for the first time. By means of X-ray diffraction (XRD), scanning electron microscope (SEM), infrared radiation (IR), and thermogravimetry (TG), the compositional and structural properties of the mixed matrix membrane with different filler content were analyzed. The results show that the compatibility of MAF-7 and Pebax is good with a filler content of 5 wt.%. The pure gas testing showed that mixed matrix membrane has a high ideal CO₂/N₂ selectivity of 124.84 together with a better CO₂ permeability of 76.15 Barrer with the optimized filler content of 5 wt.%. The obtained membrane showed 323.04% enhancement in selectivity of CO₂/N₂ and 27.74% increase in the permeability of CO₂ compared to the pristine membrane at 25 °C and 3 bar. The excellent separation performance may be due to the ligands that can afford a Lewis base active site for CO₂ binding with the uniform dispersion of MAF-7 particles in Pebax and the favorable interface compatibility. The obtained membrane overcomes the Robeson's upper bound in 2008 for CO₂/N₂ separation. This work provides a new strategy by utilizing MAFs as fillers with triazole ligand to enhance the gas separation performance of mixed matrix membranes.