Fluorinated liquid crystal monomers (FLCMs) have recently emerged as persistent organic pollutants, while microplastics serve as important environmental carriers of persistent organic pollutants. However, their interactions with aged microplastics and the consequent ecological risks remain a critical blind spot. This study examined the adsorption-desorption dynamics of a representative FLCM (4-ethoxy-2,3-difluoro-4′-(trans-4-propylcyclohexyl) biphenyl, EDPB) on aged polyethylene, polypropylene, polystyrene, and polyvinyl chloride under both abiotic (i.e., environmental) and biotic (i.e., simulated gastrointestinal) conditions. Surface oxidation and increased roughness of aged polymers markedly enhanced EDPB adsorption, through combined hydrophobic attraction and fluorine‑mediated dipole interactions. Desorption was strongly medium dependent. In simulated gastric fluid, pepsin facilitated partial release (12.6–24.8%) by disrupting π–π interactions and promoting surface hydration. In contrast, intestinal components induced substantial remobilization (up to 52.8%) via the formation of hydrophobic cavities and micelle-like structures, increasing dissolved EDPB concentrations by approximately 20 μg L−1. This biphasic desorption profile highlights the critical role of intestinal processes in remobilizing adsorbed FLCMs and elevating their bioaccessible fractions. Subsequent cytotoxicity assays in Caco‑2 cells showed dose‑ and time‑dependent inhibition of cell viability, with transcriptomic analysis delineating a mitochondrial dysfunction–driven cascade. EDPB acts as a metabolic disruptor that impairs mitochondrial energetics and redox homeostasis, triggering downstream genomic instability and cell cycle arrest, which ultimately implicating oxidative stress–mediated apoptosis. This work synthesizes critical insight into the coupled environmental and biological behaviors of FLCMs, revealing their potential as transboundary persistent toxic substances and advancing the understanding of their risks in microplastic‑dominated systems.

Fluorinated liquid crystal monomers (FLCMs) are emerging aquatic pollutants that co-occur with microplastics (MPs); however, their combined ecological impacts remain poorly understood. This study investigated the interactions between a representative FLCM, 4-Ethoxy-2,3-difluoro-4′-(trans-4-propylcyclohexyl) biphenyl (EDPB), and four major types of MPs: polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). The results revealed plastic-type-dependent adsorption capacities (PE > PS > PP > PVC; 380–850 μg/g) through distinct mechanisms: hydrophobic interactions predominantly influenced PE and PP adsorption, while π-π coordination enhanced PS binding. Microcosm experiments demonstrated that MP-EDPB composites significantly altered sediment microbiomes, showing consistent declines in Proteobacteria abundance (27–29 % vs 36.8 % in controls), pathogen enrichment in marine sediments (Acinetobacter 1.2 → 3.5 %; Vibrio 0.8 → 2.1 %), and ecosystem-specific functional disruptions. Notably, marine systems exhibited greater biodiversity shifts, while freshwater environments showed stronger nitrogen cycle inhibition. These findings provide mechanistic insights into FLCM-MP co-pollution effects on aquatic ecosystems. Environmental implication: Liquid crystal monomers (LCMs) and microplastics (MPs) are emerging contaminants that increasingly co-occur in aquatic ecosystems, yet their interactions and co-exposure risks remain poorly understood. This study demonstrated that the adsorption of LCMs onto microplastics was significantly influenced by plastic type, with equilibrium capacities (Q_max) following the order: PE (849.5 ± 1.2 μg/g) > PS (825.3 ± 0.8 μg/g) > PP (629.1 ± 0.3 μg/g) > PVC (380.2 ± 0.2 μg/g). The MPs-LCMs composites affected microbial composition and functions in sediments across both freshwater and seawater environments. These findings provide a quantitative basis for assessing the environmental partitioning and potential ecological risks associated with MPs-LCMs composite pollutants.

We use the Reynolds-averaged Navier-Stokes (RANS) equations with a full Reynolds stress model (RSM) to study the effect of the corner angle in supersonic corner flow. RANS data are compared to reference direct numerical simulation of fully developed a square duct flow, which support predictive capability of secondary flows from Stress-ω RSM. We then carry out a parametric study by changing the corner angle in the range θ=45°-135°, focusing on the effect on the mean streamwise and secondary flow. The maximum strength of the secondary flows of about 0.015u∞ occurs for θ=90°, which is similar to what is found in fully developed square ducts. Secondary eddies have approximately unit aspect ratio, and they maintain their shape for different corner angles by translating in the direction parallel to the closest wall. As a result, the position of the vortex center can be described by a simple geometrical transformation of the wall-parallel coordinate. We find that small corner angles are responsible for locally relaminarization flow at the corner, but otherwise the mean streamwise velocity profiles transformed according to van Driest following the canonical law-of-the-wall.