Coacervation is a liquid-liquid phase separation process in which macromolecular, amphiphilic, macroionic, or colloidal components spontaneously demix into a dense coacervate phase and a dilute surrounding phase. In this review, we use the term in a focused physicochemical sense, chiefly for systems in which macromolecular interactions drive the formation of a condensed liquid phase distinct from the surrounding solution. This review examines the physicochemical principles that govern simple and complex coacervation, emphasizing electrostatic interactions, counterion release, hydrogen bonding, hydrophobic forces, pH, ionic strength, temperature, and sequence patterning. We emphasize that coacervation results from a system-dependent balance of enthalpic and entropic contributions, molecular architecture, and environmental conditions. We discuss representative systems including proteins, polysaccharides, peptides, nucleic acids, and synthetic polyelectrolytes, with particular attention to multicomponent systems and molecular composition and sequence-dependent interactions. Special attention is given to how molecular architecture and environmental conditions determine droplet formation, stability, viscoelasticity, and transitions between liquid-like, gel-like, and solid states. We distinguish thermodynamic stability from kinetic persistence and coacervation from related phenomena such as aggregation, desolvation, gelation, and precipitation. Coacervates can concentrate reactants, alter local chemical reactivity, and create microenvironments potentially favorable for prebiotic chemistry. These properties support their use of membrane-free compartmentalization and protocell-like organization, although their relevance to the emergence of life remains hypothesis-dependent. Finally, we highlight unresolved challenges, including the limited predictive capability of current theories and the need to integrate multicomponent, sequence-specific, and nonequilibrium effects into quantitative frameworks. Overall, this review aims to clarify the physicochemical basis of coacervation while distinguishing established behavior from broader hypotheses about soft-matter organization, biomolecular condensates, and the emergence of life.
Biopolymer-based food-packaging films and related formats are widely investigated as alternatives to petroleum-derived plastics; however, their practical use remains limited by moisture sensitivity, weak wet integrity, insufficient barrier performance, and limited active functionality. Calcium functionalization provides a potential route to address some of these limitations through soluble Ca2+ salts or particulate Ca-based materials. This review critically examines Ca-functionalized biopolymer-based food-packaging systems using a structure–function–processing–safety framework. Natural-biopolymer matrices form the primary evidence base, while studies using synthetic matrices such as PLA, PVA, or EVOH are identified separately according to polymer class, packaging format, and evidentiary relevance. Soluble Ca salts, including Ca chloride, Ca lactate, and Ca gluconate, can form Ca2+-mediated junction zones in carboxylate-rich alginate and low-methoxyl pectin, where ionic crosslinking is comparatively well established. In chitosan-containing and protein-based systems, the reported effects are less uniform and may involve local coordination, charge screening, stabilization of anionic partners, aggregation, or double-network formation rather than an extended Ca-crosslinked network. Changes in swelling, solubility, or barrier performance are therefore treated as functional outcomes and not as direct proof of network densification unless supporting structural evidence was reported. Particulate Ca materials extend the role of Ca beyond ionic crosslinking. Nano-CaCO₃ and porous/vaterite CaCO₃ can contribute to reinforcement, barrier modification, UV shielding, and active-agent delivery, whereas CaO and CaO₂ provide reactive antimicrobial functions through alkalinity or moisture-triggered H₂O₂ release. Hydroxyapatite and related Ca phosphate phases offer opportunities for mineral reinforcement, adsorption, active-agent immobilization, and circular sourcing from Ca-rich biowastes. Across the reviewed systems, improvements in wet integrity, stiffness, barrier performance, or antimicrobial activity were frequently accompanied by lower extensibility, opacity, aggregation, altered interfacial pH, oxidative or sensory risks, or incomplete release control. However, many studies did not measure the corresponding paired property, limiting complete assessment of these trade-offs. Overall, Ca-functionalized biopolymer-based packaging systems should be designed not by maximizing Ca loading, but by matching Ca chemistry with polymer structure, processing conditions, release behavior, food-contact safety, and the intended preservation function.
Despite numerous studies on desulfurized rubber modified asphalt (DRMA), a mechanistic understanding of how desulfurization-driven structural evolution dictates interfacial interactions and engineering properties is lacking, constraining DRMA development from preparation to green applications. To address this, the present review begins by systematically delineating the pristine composition and hierarchical structure of crumb rubber, alongside the structural evolution of its vulcanized network during desulfurization. Subsequently, a critical and comparative evaluation of prevailing desulfurization technologies is presented, with emphasis on their inherent reaction mechanisms, technical characteristics, and practical applicability. Building upon this foundation, the dissolution and swelling behaviors, microstructural reorganization, and molecular level interaction mechanisms between desulfurized rubber and asphalt are comprehensively reviewed, aiming to unravel the physicochemical origins of enhanced compatibility and overall material performance. The consequential effects on the storage stability, high-temperature rheological properties, intermediate-temperature fatigue resistance, and low-temperature cracking resistance of DRMA are further discussed in depth. Moreover, the environmental performance and low-carbon application potential of DRMA are explored by considering pollutant emissions, carbon emissions, and environmental sustainability. By holistically integrating current knowledge across the domains of material structural chemistry, interfacial interaction physics, engineering rheology, and sustainability science, this review constructs a coherent mechanistic framework. Ultimately, it offers forward-looking perspectives for the intelligent and sustainable design of high-performance rubber modified asphalt materials, while simultaneously promoting the high-value circular utilization of waste tires.
Advanced composite coatings/films present a promising strategy for the preservation of fruits postharvest by effectively addressing the fundamental thermodynamic mismatch between the high surface tension of biopolymer formulations and the low surface energy of epicuticular waxes. While this discrepancy typically results in dewetting and adhesion failure, embracing an interface-centric framework opens up new opportunities for overcoming these interfacial energy barriers. This review systematically evaluates advanced matrix restructuring strategies, including amphiphilic grafting, biomimetic coacervation, amyloid fibrillation and Pickering emulsions, which enable conformal wetting and long-term structural stability. Furthermore, the incorporation of functional nanoscale units (e.g., carbon dots, metal-organic frameworks, and artificial nanozymes) transforms these passive physical barriers into intelligent and active interfaces. From a structure-function perspective, we elucidate the mechanisms that modulate moisture migration, respiratory intensity, antimicrobial defense, and oxidative stress, emphasizing how engineered microenvironments can be tailored for climacteric fruits, non-climacteric fruits, citrus peels, and fresh-cut tissues. Ultimately, this review identifies key challenges and future research directions, providing insights for next-generation sustainable postharvest packaging.
Sensitive detection of glyphosate is of global importance due to its widespread use and persistent accumulation in water, soil, and food, raising concerns related to human health and environmental safety. As a result, the development of rapid, selective, and field-deployable sensing strategies has attracted growing attention across electrochemical, fluorescent, colorimetric, and spectroscopic platforms. However, established analytical methods face practical limitations, including specialized instrumentation and sample-preparation requirements for chromatographic–mass spectrometric methods, derivatization or indirect detection in some optical methods, and potential cross-reactivity in immunoassays. Recent progress in glyphosate sensing is increasingly governed by advances in material design rather than by transduction techniques alone. Glyphosate's phosphonate, carboxylate, and amine functionalities mediate metal coordination, electrostatic interactions, and hydrogen bonding at sensing interfaces. These interactions influence analyte adsorption and recognition and, depending on the sensing platform, interfacial charge transfer or optical signal generation. Carbon-based materials, noble and non-noble metals, metal oxides, conducting polymers, molecularly imprinted polymers (MIPs), and metal-organic frameworks (MOFs) provide tailored surface chemistry, catalytic activity, molecular recognition, and adsorption capability essential for effective glyphosate detection. By controlling analyte recognition, interfacial interactions, and signal amplification, these functional materials play a central role in improving sensing performance. This review connects material properties with glyphosate-interface behaviour while highlighting remaining challenges associated with matrix interference, glyphosate complexation, sensor reproducibility, and validation in real samples.
