Advances in Colloid and Interface Science最新文献

Proteins in ionic liquids (ILs) and deep eutectic solvents (DESs) have gained significant attention due to their potential applications in various fields, including biocatalysis, bioseparation, biomolecular delivery, and structural biology. Scattering approaches including dynamic light scattering (DLS) and small-angle X-ray and neutron scattering (SAXS and SANS) have been used to understand the solution behavior of proteins at the nanoscale and microscale. This review provides a thorough exploration of the application of these scattering techniques to elucidate protein properties in ILs and DESs. Specifically, the review begins with the theoretical foundations of the relevant scattering approaches and describes the essential solvent properties of ILs and DESs linked to scattering such as refractive index, scattering length density, ion-pairs, liquid nanostructure, solvent aggregation, and specific ion effects. Next, a detailed introduction is provided on protein properties such as type, concentration, size, flexibility and structure as observed through scattering methodologies. This is followed by a review of the literature on the use of scattering for proteins in ILs and DESs. It is highlighted that enhanced data analysis and modeling tools are necessary for assessing protein flexibility and structure, and for understanding protein hydration, aggregation and specific ion effects. It is also noted that complementary approaches are recommended for comprehensively understanding the behavior of proteins in solution due to the complex interplay of factors, including ion-binding, dynamic hydration, intermolecular interactions, and specific ion effects. Finally, the challenges and potential research directions for this field are proposed, including experimental design, data analysis approaches, and supporting methods to obtain fundamental understandings of complex protein behavior and protein systems in solution. We envisage that this review will support further studies of protein interface science, and in particular studies on solvent and ion effects on proteins.

Adsorption of surfactants to fluid interfaces occurs in numerous technological and daily-life contexts. The coverage at the interface and other properties of the formed adsorption layers determine the performance of a surfactant with regard to the desired application. Given the importance of these applications, there is a great demand for the comprehensive characterization and understanding of surfactant adsorption layers. In this review, we provide an overview of suitable experimental and simulation-based techniques and review the literature in which they were used for the investigation of surfactant adsorption layers. We come to the conclusion that, while these techniques have been successfully applied to investigate Langmuir monolayers of water-insoluble surfactants, their application to the study of Gibbs adsorption layers of water-soluble surfactants has not been fully exploited. Finally, we emphasize the great potential of these methods in providing a deeper understanding of the behavior of soluble surfactants at interfaces, which is crucial for optimizing their performance in various applications.

Colloidal particles of spherical shape are important building blocks for nanotechnological applications. Materials with tailored physical properties can be directly synthesized from self-assembled particles, as is the case for colloidal photonic crystals. In addition, colloidal monolayers and multilayers can be exploited as a mask for the fabrication of complex nanostructures via a colloidal lithography process for applications ranging from optoelectronics to sensing. Several techniques have been adopted to modify the shape of both individual colloidal particles and colloidal masks. Thermal treatment of colloidal particles is an effective route to introduce colloidal particle deformation or to manipulate colloidal masks (i.e. to tune the size of the interstices between colloidal particles) by heating them at elevated temperatures above a certain critical temperature for the particle material. In particular, this type of morphological manipulation based on thermal treatments has been extensively applied to polymer particles. Nonetheless, interesting shaping effects have been observed also in inorganic materials, in particular silica particles. Due to their much less complex implementation and distinctive shaping effects in comparison to dry etching or high energy ion beam irradiation, thermal treatments turn out to be a powerful and competitive tool to induce colloidal particle deformation. In this review, we examine the physicochemical principles and mechanisms of heat-induced shaping as well as its experimental implementation. We also explore its applications, going from tailored masks for colloidal lithography to the fabrication of colloidal assemblies directly useful for their intrinsic optical, thermal and mechanical properties (e.g. thermal switches) and even to the synthesis of supraparticles and anisotropic particles, such as doublets.

Surfactant mass transport towards an interface plays a critical role during formation of emulsions, foams and in industrial processes where two immiscible phases coexist. The understanding of these mechanisms as experimentally observed by dynamic interfacial tension measurements, is crucial. In this review, theoretical models describing both equilibrated systems and surfactant kinetics are covered. Experimental results from the literature are analysed based on the nature of surfactants and the tensiometry methods used. The innovative microfluidic techniques that have become available to study both diffusion and adsorption mechanisms during surfactant mass transport are discussed and compared with classical methods. This review focuses on surfactant transport during formation of droplets or bubbles; stabilisation of dispersed systems is not discussed here.

Solid Oxide Fuel Cells (SOFCs) have proven to be highly efficient and one of the cleanest electrochemical energy conversion devices. However, the commercialization of this technology is hampered by issues related to electrode performance degradation. This article provides a comprehensive review of the various degradation mechanisms that affect the performance and long-term stability of the SOFC anode caused by the interplay of physical, chemical, and electrochemical processes. In SOFCs, the most used anode material is nickel-yttria stabilized zirconia (Ni–YSZ) due to its advantages of high electronic conductivity and high catalytic activity for H₂ fuel. However, various factors affecting the long-term stability of the Ni–YSZ anode, such as redox cycling, carbon coking, sulfur poisoning, and the reduction of the triple phase boundary length due to Ni particle coarsening, are thoroughly investigated. In response, the article summarizes the state-of-the-art diagnostic tools and mitigation strategies aimed at improving the long-term stability of the Ni–YSZ anode.

Two-dimensional covalent organic frameworks (2D COFs) are an emerging class of crystalline porous materials formed through covalent bonds between organic building blocks. COFs uniquely combine a large surface area, an excellent stability, numerous abundant active sites, and tunable functionalities, thus making them highly attractive for numerous applications. Especially, their abundant active sites and weak interlayer interaction make these materials promising candidates for tribological research. Recently, notable attention has been paid to COFs as lubricant additives due to their excellent tribological performance. Our review aims at critically summarizing the state-of-art developments of 2D COFs in tribology. We discuss their structural and functional design principles, as well as synthetic strategies with a special focus on tribology. The generation of COF thin films is also assessed in detail, which can alleviate their most challenging drawbacks for this application. Subsequently, we analyze the existing state-of-the-art regarding the usage of COFs as lubricant additives, self-lubrication composite coatings, and solid lubricants at the nanoscale. Finally, critical challenges and future trends of 2D COFs in tribology are outlined to initiate and boost new research activities in this exciting field.

Diffuse soft matter interfaces take many forms, from end-tethered polymer brushes or adsorbed surfactants to self-assembled layers of lipids. These interfaces play crucial roles across a multitude of fields, including materials science, biophysics, and nanotechnology. Understanding the nanostructure and properties of these interfaces is fundamental for optimising their performance and designing novel functional materials. In recent years, reflectometry techniques, in particular neutron reflectometry, have emerged as powerful tools for elucidating the intricate nanostructure of soft matter interfaces with remarkable precision and depth. This review provides an overview of selected recent developments in reflectometry and their applications for illuminating the nanostructure of diffuse interfaces. We explore various principles and methods of neutron and X-ray reflectometry, as well as ellipsometry, and discuss advances in their experimental setups and data analysis approaches. Improvements to experimental neutron reflectometry methods have enabled greater time resolution in kinetic measurements and elucidation of diffuse structure under shear or confinement, while innovation in analysis protocols has significantly reduced data processing times, facilitated co-refinement of reflectometry data from multiple instruments and provided greater-than-ever confidence in proposed structural models. Furthermore, we highlight some significant research findings enabled by these techniques, revealing the organisation, dynamics, and interfacial phenomena at the nanoscale. We also discuss future directions and potential advancements in reflectometry techniques. By shedding light on the nanostructure of diffuse interfaces, reflectometry techniques enable the rational design and tailoring of interfaces with enhanced properties and functionalities.

Despite critical advances in regenerative medicine, the generation of definitive, reliable treatments for musculoskeletal diseases remains challenging. Gene therapy based on the delivery of therapeutic genetic sequences has strong value to offer effective, durable options to decisively manage such disorders. Furthermore, scaffold-mediated gene therapy provides powerful alternatives to overcome hurdles associated with classical gene therapy, allowing for the spatiotemporal delivery of candidate genes to sites of injury. Among the many scaffolds for musculoskeletal research, hydrogels raised increasing attention in addition to other potent systems (solid, hybrid scaffolds) due to their versatility and competence as drug and cell carriers in tissue engineering and wound dressing. Attractive functionalities of hydrogels for musculoskeletal therapy include their injectability, stimuli-responsiveness, self-healing, and nanocomposition that may further allow to upgrade of them as “intelligently” efficient and mechanically strong platforms, rather than as just inert vehicles. Such functionalized hydrogels may also be tuned to successfully transfer therapeutic genes in a minimally invasive manner in order to protect their cargos and allow for their long-term effects. In light of such features, this review focuses on functionalized hydrogels and demonstrates their competence for the treatment of musculoskeletal disorders using gene therapy procedures, from gene therapy principles to hydrogel functionalization methods and applications of hydrogel-mediated gene therapy for musculoskeletal disorders, while remaining challenges are being discussed in the perspective of translation in patients.

Statement of significance

Despite advances in regenerative medicine, the generation of definitive, reliable treatments for musculoskeletal diseases remains challenging. Gene therapy has strong value in offering effective, durable options to decisively manage such disorders. Scaffold-mediated gene therapy provides powerful alternatives to overcome hurdles associated with classical gene therapy. Among many scaffolds for musculoskeletal research, hydrogels raised increasing attention. Functionalities including injectability, stimuli-responsiveness, and self-healing, tune them as “intelligently” efficient and mechanically strong platforms, rather than as just inert vehicles. This review introduces functionalized hydrogels for musculoskeletal disorder treatment using gene therapy procedures, from gene therapy principles to functionalized hydrogels and applications of hydrogel-mediated gene therapy for musculoskeletal disorders, while remaining challenges are discussed from the perspective of translation in patients.

Surfactants and foam have captured the interest of researchers worldwide due to their unique behavior of surface activity, the dynamic nature of foam formation, and simultaneous destruction. The present review focuses on the surfactants' classification, surfactant-solvent interaction, foam formation, characteristics, and a range of admixtures to enhance the foam performance. Although surfactants have been researched and developed for decades, recently, their sustainability has been given special attention. One such aspect is the development of green foaming agents from natural and renewable sources and assessing their suitability for different applications. Further, widely researched parameters are the type of surfactant, surfactant concentration, surfactant-solvent interaction, and foam production method on the foamability of a surfactant solution and related foam characteristics, including stability and texture. However, still, there is no rule to predict the best foam. Another vital concern is the non-standardization of foam assessment methods across industries and regions. Recently, research has progressed in identifying suitable admixtures for foam performance enhancement and utilizing them to produce stable foams for application in enhanced oil recovery, drug delivery, and manufacturing of aerated food products and foamed concrete. Although foam stabilization using various admixtures has been recognized well in the literature, the underlying mechanism requires further research. The interaction of surfactant and admixtures in solution is complicated and requires more research.

Surface-enhanced Raman spectroscopy (SERS) has great potential for the analysis of molecules adsorbed on metals with rough surfaces or substrates with micro−/nanostructures. Plasmonic coupling between metal nanoparticles and the morphology of the rough metal surface can produce “hot spots” that enhance Raman scattering by adsorbed molecules, typically at micro- to nanomolar concentrations, although high enhancement factors can also facilitate single-molecule detection. This phenomenon is widely applicable for chemical analysis and sensing in various fields. In this review, the latest research progress on SERS micro−/nanosensors is evaluated, and the sensors are classified according to their individual functions. Furthermore, the design principles and working mechanisms of reported SERS-active micro−/nanostructured substrates are analyzed, and the design features adopted to overcome the difficulties associated with precision detection are explored. Finally, challenges and directions for future development in this field are discussed. This review serves as a design guide for novel SERS-active substrates.