Covalent Cross-linking Research Articles

Multifunctional Cross-Linking Composite Binder Enables the Stable Performance of Si-Based Anodes for High-Energy-Density Lithium-Ion Batteries.

The intrinsic volumetric stress during cycling is the main obstacle for developing Si-based materials as high-energy-density lithium-ion battery anodes. Elastic binders have been demonstrated as an efficient approach to alleviate the stress of Si. Herein, we design a tough 3D hard/soft polymeric network (LPTS) using lithiated poly(acrylic acid), silk sericin, and highly branched tannic acid. Covalent cross-linking provides a robust mechanical strength to endure the large stress. The formed multiple hydrogen bonds with bonding energies between 3.46 and 25 kcal mol-1 can effectively dissipate the stress through sequential hydrogen bond disassociation. The multifunctional LPTS binder maintains the integrity of the Si-based electrodes during repeated discharging/charging. Additionally, Li+ can be transferred via a Li-conducting group (-COOLi), thereby enhancing the ionic conductivity of electrodes. Consequently, the Si/LPTS electrode exhibits an improved initial Coulombic efficiency and excellent durability over 400 cycles. Meanwhile, this binder is also suitable for Si-C anodes, enabling stable cycling at a high areal capacity >3.6 mAh cm-2 and delivering 72.2% capacity retention for the LFP||Si-C/LPTS full cell after 200 cycles. This study provides insight into developing efficient Si-based binders that are facile and low-cost for next-generation high-energy-density systems.

Elusive Protein-Glycosphingolipid Interactions Revealed by Membrane Anchor-Assisted Native Mass Spectrometry.

Interactions between glycan-binding proteins (GBPs) and glycosphingolipids (GSLs) present in cell membranes are implicated in a wide range of biological processes. However, studying GSL binding is hindered by the paucity of purified GSLs and the weak affinities typical of monovalent GBP-GSL interactions. Native mass spectrometry (nMS) performed using soluble model membranes is a promising approach for the discovery of GBP ligands, but the detection of weak interactions remains challenging. The present work introduces MEmbrane ANchor-assisted nMS (MEAN-nMS) for the detection of low-affinity GBP-GSL complexes. The assay utilizes a membrane anchor, produced by covalent cross-linking of the GBP and a lipid in the membrane, to localize the GBP on the surface and promote GSL binding. Ligands are identified by nMS detection of intact GBP-GSL complexes (MEAN-nMS) or using a catch-and-release (CaR) strategy, wherein GSLs are released from GBP-GSL complexes upon collisional activation and detected (MEAN-CaR-nMS). To establish reliability, a library of purified gangliosides incorporated into nanodiscs was screened against human immune lectins, and the results compared with affinities of the corresponding ganglioside oligosaccharides. Without a membrane anchor, nMS analysis yielded predominantly false negatives. In contrast, all ligands were identified by MEAN-(CaR)-nMS, with no false positives. To highlight the potential of MEAN-CaR-nMS for ligand discovery, a natural library of GSLs was incorporated into nanodiscs and screened against human and viral proteins to uncover elusive ligands. Finally, nMS-based detection of GSL ligands directly from cells is demonstrated. This breakthrough paves the way for shotgun glycomics screening using intact cells.

3D‐Printed Hydrogel Filter for Biocatalytic CO2 Capture

AbstractInnovative scalable CO2 capture technologies are urgently needed to combat the climate crisis. Reactive absorption in alkaline liquids, an essential process for capturing CO2 at atmospheric pressure, requires high gas–liquid contact and fast reaction kinetics. To meet these needs, self‐supporting hydrogel CO2 gas–liquid contactors (or simply “CO2 filters”) containing the CO2 selective catalyst carbonic anhydrase (CA) are developed using the direct ink writing additive manufacturing approach. The multifunctional filters are composed of semi‐interpenetrating polymer network hydrogels (IPNHs) of poly (ethylene glycol) diacrylate/poly (ethylene oxide) (PEG‐DA/PEO) upon photocuring during 3D printing. Formulations with PEG‐DA levels of 30–60 wt% are sufficiently homogeneous and reactive to produce coherent grids. Based on operational parameters, a 56 wt% PEG‐DA formulation is selected to continuously print self‐supporting 3D stacked cylindrical grids, with or without enzymes in ink. The resulting enzyme‐laden IPHN filters deliver ≈3 times higher CO2 capture efficiency than the no‐enzyme control filters in a laboratory‐scale absorption column test. However, the enhancement effect decreases significantly within 2 d of operation, likely due to burst release of enzymes caused by the flowing solution. Covalent crosslinking of CA near the surface, which can improve durability and CO2 capture performance, will be evaluated in future studies.

A highly durable and biocompatible bionic collagen implant with exceptional anti-calcification and collagen regeneration capabilities for improved skin rejuvenation

Skin aging, a complex and inevitable biological process, considerably impacts an individual’s physical appearance and overall well-being. While collagen-based implants hold potential for skin rejuvenation, their clinical application is limited by the poor durability of non-crosslinked implants and the negative impacts of crosslinking agents, such as cytotoxicity and calcification. Herein, we report a highly durable and biocompatible bionic collagen implant for superior skin rejuvenation with advanced anti-calcification characteristics and enhanced collagen regeneration. Utilizing biomimetic self-assembly and covalent crosslinking approach, we successfully created long-lasting and biomimetic collagen implants with densely-packed collagen fibers. Crosslinking of collagen fibers with a low concentration of N-hydroxysuccinimide activated suberic acid (NHS-SA) was highly efficient, resulting in complete crosslinking and thicker collagen fiber formation with a uniform network structure. Compared with glutaraldehyde-crosslinked collagen fibers, NHS-SA-crosslinked assembled collagen fibers (NACF) demonstrated considerably improved thermal stability and durability. Furthermore, the NACF implant exhibited superior biocompatibility, establishing NHS-SA crosslinked collagen fibers as a safer and more bioactive choice for implant applications. In mouse subcutaneous implant models, the NACF implant outperformed other collagen implants, demonstrating exceptional biocompatibility, effective collagen regeneration, and excellent anti-calcification potential. The NACF implant shows immense promise in collagen regeneration, offering considerable potential to advance skin rejuvenation therapies.

High-performance glued-bamboo through activation of chemical bonding interface

Bamboo glue products are widely used in decoration, construction and transportation. Bamboo is fast growing, strong and inexpensive, making it one of the ideal processing materials to replace steel and wood. Here we present a process for the production of high performance bamboo glue products. In this process, the conversion of natural bamboo surface (NBS) to oxidized bamboo surface (OBS) is a critical step prior to hot pressing, as it provides the bamboo interface with active sites (aldehyde groups) for chemical cross-linking with the adhesive. Subsequent covalent crosslinking with branched chain amine (PAXN) compounds is based on Schiff base chemistry. The improved properties of the oxidized bamboo specimens were attributed to chemical cross-linking within the oxidized bamboo-binder interface (OBI-PAXN) and further densification of the bamboo adhesive interface. The dry/hot/boiling water bond strength of OBI-PA6 N was increased by 130 % (7.5 MPa)/148 % (5.05 MPa)/130 % (3.26 MPa) compared to NBI-PA6 N (3.26 MPa, 2.04 MPa, 0.88 MPa). Its bonding strength and bending strength are superior to commercial PF resins. The combination of excellent mechanical properties with the rich, renewable and sustainable nature of bamboo makes it very attractive for engineering applications.

Revolutionizing marine Protection: Innovative designs for In-Situ applicable underwater antifouling superoleophobic coatings

There is a high demand for underwater antifouling coatings for marine engineering and underwater activities. However, In-situ painting coating in a water environment for various large substrate surfaces is ideal but extremely challenging. In this work, we present a novel approach to achieving a fouling-repellent superoleophobic coating that can be directly applied underwater. The coating was prepared facilely via one-pot synthesis using epoxy resin E51 and 2-hydroxyethyl methacrylate as main components. This method involves the hydrolytic migration of side chains (Trimethylsilyl Methacrylate) interlocked with covalent cross-linking, enabling direct adhesion to a variety of wet substrates underwater without the need for surface pre-treatment. The resulting coating exhibits both underwater superoleophobicity (underwater oil contact angle＞150°) and versatile, sustainable substrate adhesion with a shear strength of up to 50 kPa, making it suitable for various underwater applications, such as oil/water separation. This work represents a facile and novel paradigm for designing future underwater antifouling coatings with superoleophobic properties and direct underwater adhesion.

Novel Hydrophobic Covalent Cross-Linking Poly(terphenyl Isatin Piperidinium) with Poly(triphenylpyridine) for Anion Exchange Membranes

Novel Hydrophobic Covalent Cross-Linking Poly(terphenyl Isatin Piperidinium) with Poly(triphenylpyridine) for Anion Exchange Membranes

Thermo-responsive composite nanoparticles based on hydroxybutyl chitosan oligosaccharide: Fabrication, stimulus release and cancer therapy

Designing thermo-responsive nanocarriers based on biopolymers is fascinating and challenging for cancer therapy. In this study, thermo-responsive composite nanoparticles (CNPs) were prepared using hydroxybutyl chitosan oligosaccharide (HBCOS) and sodium caseinate (SC) via electrostatic interactions and covalent crosslinking. The temperature-responsive behaviors of CNPs were induced by the breakage of hydrogen bonds and the shrinkage of chains in nanoparticles. The CNPs exhibited concentration-independent thermo-responsive behavior, non-adsorption aggregation, and non-hemolysis, suggesting excellent stability and thermo-sensitivity. The initial release rate and final amount of DOX released from CNPs at 42 °C were higher than that at 37 °C, showing a thermo-responsive release, which was also more prominent at lower pH. The release of DOX from CNPs followed first order kinetics based on Fickian diffusion. In vitro cytotoxicity assays confirmed the thermo-responsive antitumor activity of DOX-loaded CNPs as the HT-29 cell viability incubated with DOX-loaded CNPs at 42 °C was significantly lower than that at 37 °C. Cellular uptake experiments proved that DOX-loaded CNPs accumulated in the cytoplasm after being endocytosed and promoted DOX release by increasing environment temperature. This study generated stable thermo-sensitive CNPs based on biopolymers, which can be used as potential nanocarriers for the controlled release of anticancer drugs for cancer therapy.

Repairing surface defects of carbon fibers: Electrostatic spraying nano-carbons on stabilized PAN-fibers and subsequent thermal annealing

The introducing of nanomaterials on the carbon fibers (CFs) surface is an effective method for repairing surface defects. Due to the chemical inertness of CFs surface, the bonding force between reinforcing material and CFs is weak. In this paper, nano-carbons (graphene oxide and graphene quantum dots) were assembled to defects on surface of stabilized fibers (SFs) through electrostatic spraying assisted by airflow and then thermally annealed to enhance bonding force between nano-carbons and fibers. The distribution of nano-carbons on fibers surface was explored and it was found that the nano-carbons were directionally covered on or filled in defects on fibers surface to reduce specific surface area and pore volume. The chemical structures on fiber surface were discussed by X-ray photoelectron spectroscopy and atomistic ReaxFF molecular dynamics simulation, and it suggested that covalent crosslinking occurred between CFs surface and nano-carbons. And further, the nano-scratch on fibers surface revealed a significant increase in the bonding force between nano-carbons and fiber after thermal annealing. The maximum tensile strength and Young´s modulus of CFs with nano-carbons increased 24.36% and 38.63%, respectively. Subsequently, the finite element simulation ABAQUS was adopted to demonstrate that the addition of nano-carbons alleviated stress concentration at defects on CFs surface. At the same time, the smaller stress and stress diffusion were found in CFs reinforced by graphene oxide than that with graphene quantum dots.

Recyclable Covalent Adaptable Polystyrene Networks Using Boronates and TetraAzaADamantanes.

With an ever-increasing annual production of polymers and the accumulation of polymer waste leading to progressively adverse environmental consequences, it has become important that all polymers can be efficiently recycled at the end of their life cycle. Especially thermosets are intrinsically difficult to recycle because of their permanent covalent cross-links. A possible solution is to switch from using thermosets to covalent adaptable networks, sparking the rapid development of novel dynamic covalent chemistries and derived polymer materials. Next to development of these innovative polymer materials, there is also an evident advantage of merging the virtues of covalent adaptable networks with the proven material properties of widely used commodity plastics, by introducing dynamic covalent bonds in these original thermoplastic materials to obtain recyclable thermosets. Here we report the synthesis and characterization of a polystyrene polymer, functionalized with TetraAzaADamantanes and cross-linked with dynamic covalent boronic esters. The material properties were characterized for different degrees of cross-linking. The materials showed good solvent resistance with a high remaining insoluble fraction. In line with the typical behavior of traditional covalent adaptable networks, the prepared polystyrene-based boronate-TetraAzaADamantane materials were able to undergo stress relaxation. The material relaxation was also shown to be tunable by mixing with an acid catalyst. Lastly, the materials could be recycled at least 2 times.

Exploration on the multifunctional hydrogel dressings based on collagen and oxidized sodium: A novel approach for dynamic wound treatment and monitoring

Collagen-based hydrogels have attracted growing interest as a promising type of wound dressing. However, designing a multifunctional hydrogel dressing capable of both treating and monitoring dynamic wounds remains a bottleneck. This issue is facilely addressed by developing hydrogel dressings based on collagen and oxidized sodium alginate (OSA) using an innovative biphasic solvent system of acetic acid/1-ethyl-3-methylimidazolim acetate (AA/[EMIM][Ac]). Compatible hydrogel network structure can be achieved by adopting highly polar solvent of AA/[EMIM][Ac] to shield strong electrostatic adsorption between two polyelectrolytes with opposite charges. Through the simple Schiff base click reaction, various compositions ratios of OSA/collagen in the resultant hydrogels were systematically examined. Sufficient covalent crosslinking bonds endowed collagen-based hydrogels with expected physicochemical properties including stable mechanical properties (1007.87 Pa), improved thermal stability (66.59 °C), reduced degradation rate (23.51 %) and compact porous microstructure (44.17 μm). Meanwhile, the biological hydrogels with advantageous responses demonstrated favorable injectability, desirable self-healing capacity, satisfactory biocompatibility and accelerated wound healing performance. More interestingly, the electronic biosensor assembled by the resultant hydrogels was able to precisely monitor human activity. Our findings revealed that the multifunctional OSA-crosslinked collagen hydrogels were ideal candidates for wound dressings in the field of biomedical materials.

Exploring marine-based compounds as cross-linkers to improve the biocompatibility and sustainability of chitosan-based hydrogels

Chitosan is one of the most promising natural polymers, its fundamental scientific research is growing uninterruptedly and has been applied in a wide and varied range of domains, including biomedical and water treatment applications. Therefore, the search and implementation of non-synthetic and non-toxic cross-linkers for chitosan-based hydrogels is crucial for the development of more sustainable and biocompatible materials. Herein, an alternative approach has been developed to explore and exploit methanolic and aqueous extracts from five red seaweed species as covalent cross-linkers for chitosan-based hydrogels. The formation of a gel could be denoted for all extracts, whereas the protein-rich methanolic extractions afforded instantaneous gel-forming ability and greater stiffness and stability. The obtained hydrogels present large porous system with high degrees of swelling up to ca. 3000 %, and were successfully applied as dye adsorbent to remove industrial dye methyl orange withing a circular process with adsorption capacities of 728.46 ± 66.17 mg/g. Furthermore, cytotoxicity and cell-adhesion studies revealed the biocompatibility of the hydrogels and their potential applicability for tissue-engineering. This work demonstrated that methanolic and aqueous extracts from different red seaweed species could replace toxic cross-linkers. Furthermore, the unexpected ability of some extracts could pave the way for the development of new formulations for additive manufacturing, in particular for 3D printing approaches.

Substrate stress relaxation regulates neural stem cell fate commitment

Adult neural stem cells (NSCs) reside in the dentate gyrus of the hippocampus, and their capacity to generate neurons and glia plays a role in learning and memory. In addition, neurodegenerative diseases are known to be caused by a loss of neurons and glial cells, resulting in a need to better understand stem cell fate commitment processes. We previously showed that NSC fate commitment toward a neuronal or glial lineage is strongly influenced by extracellular matrix stiffness, a property of elastic materials. However, tissues in vivo are not purely elastic and have varying degrees of viscous character. Relatively little is known about how the viscoelastic properties of the substrate impact NSC fate commitment. Here, we introduce a polyacrylamide-based cell culture platform that incorporates mismatched DNA oligonucleotide-based cross-links as well as covalent cross-links. This platform allows for tunable viscous stress relaxation properties via variation in the number of mismatched base pairs. We find that NSCs exhibit increased astrocytic differentiation as the degree of stress relaxation is increased. Furthermore, culturing NSCs on increasingly stress-relaxing substrates impacts cytoskeletal dynamics by decreasing intracellular actin flow rates and stimulating cyclic activation of the mechanosensitive protein RhoA. Additionally, inhibition of motor-clutch model components such as myosin II and focal adhesion kinase partially or completely reverts cells to lineage distributions observed on elastic substrates. Collectively, our results introduce a unique system for controlling matrix stress relaxation properties and offer insight into how NSCs integrate viscoelastic cues to direct fate commitment.

Fabrication of enhanced aerogel template oleogels with enzyme-hydrolyzed soy protein isolate and covalent cross-linking

In recent years, the utilization of aerogel templates in oleogels to replace animal fats has garnered considerable attention due to health concerns. This study employed a “fiber-particle core-shell nanostructure model” to combine sodium carboxymethylcellulose (CMCNa) and soy protein isolate (SPI) or SPI hydrolysate (SPIH), and freeze-dried to form aerogel template, which was then dipped into oil to induce oleogels. The results showed that adding SPIH significantly improved the physicochemical properties of oleogels. The results of ζ-potential, FTIR, and rheology demonstrated a stronger binding of SPIH to CMC-Na compared to SPI. The CMC-Na-SPIH aerogels exhibited a coarser surface and denser network structure in contrast to CMC-Na-SPI aerogels, with an oil holding capacity (OHC) of up to 84.6 % and oil absorption capacity (OAC) of 47.4 g/g. The mechanical strength of oleogels was further enhanced through chemical crosslinking. Both CMC-Na-SPI and CMC-Na-SPIH oleogels displayed excellent elasticity and reversible compressibility, with CMC-Na-SPIH oleogels demonstrating superior mechanical strength. Additionally, CMC-Na-SPIH oleogels exhibited enhanced slow release of antimicrobial substances and antioxidant properties. Increasing the content of SPI/SPIH significantly improved the mechanical strength, antioxidant capacity, and OHC of the oleogels. This research presents a straightforward and promising approach to enhance the performance of aerogel template oleogels.

Flexible and recyclable thermally conductive phase change composites with shape stability

AbstractForm‐stable and flexible highly thermally conductive phase change composites are crucial for thermal management. In this work, based on the associative exchangeable crosslinkers derived from the reaction of epoxidized soybean oil (ESO) and sebacic acid (SA), a kind of flexible and recyclable thermally conductive phase change composite with shape stability is prepared. The shape stabilization is achieved through the co‐cooperation of expanded graphite (EG) and the dynamic covalent crosslinking network. The thermal conductivity is enhanced by embedding with boron nitride (BN). When the mass fraction of BN is 25%, the thermal conductivity of the composite can reach 4.03 W/(m·K). The results indicate that the prepared PCMs composites have excellent flexibility and form stability, suggesting the potential application in the thermal management for electronic devices. The presence of dynamic exchangeable bonds makes the matrix degradable under mild conditions, enabling the recycling of valuable thermally conductive fillers, which proves to be highly sustainable. This work introduces a novel method for preparing flexible and recyclable thermally conductive phase change composites with shape stability vitrimer.

Lightweight, robust and conductive MXene/SiO2 nanofiber aerogels for excellent sensing and thermal management properties

Flexible pressure sensors embody outstanding mechanical and sensing performance, particularly in the fields of personal health monitoring and artificial intelligence, while catering to multifunctional applications resilient against harsh weather conditions. Among these, Ti3C2Tx MXene-based aerogel materials with high surface area and excellent conductivity have attracted a lot of attention. However, there are big challenges in improving the mechanical properties at low densities and designing multi-level pore structures. Herein, the prepared silane monomers (MP) are firstly synthesized by 3-(Trimethoxysilyl) propyl methacrylate (MPTES) and polyethylene glycol diacrylate (PEGDA), then polydopamine-modified silicon dioxide (PDA-SiO2) nanofibers employed with MXene nanosheets form covalent cross-linking nanofiber aerogels. The multi-level stable structure improves both mechanical strength and elasticity. The assembled MXene/MP/PDA-SiO2 pressure sensors exhibit a high sensitivity of −0.83 kPa−1, a rapid response time of 48 ms, a minimum 1 % strain detection limit, and reliable stability over 10,000 cycles. Furthermore, these sensors can be used for human motion detection and health diagnostics, and show good personal thermal management performance. This work holds a promising candidate for the next generation of multifunctional flexible electronic devices.

UV-curing 3D printing of high-performance, recyclable, biobased photosensitive resin enabled by dual-crosslinking networks

UV-curing 3D printing technologies based on vat photopolymerization have gained increasing interest in rapidly manufacturing high-quality custom-designed objects. However, they are still challenged by the non-renewability of photosensitive resins in future large-scale applications. Herein, a high-performance, recyclable, biobased carboxyl-terminated unsaturated polyester is developed from itaconic acid and bio-diols, which involves the formation of dual-crosslinking networks, i.e., covalent crosslinking of unsaturated double bonds and non-covalent coordination interaction between terminal carboxyl and ZnCl2. Dual-crosslinking networks greatly increase tensile strength from 31 to 43 MPa by 40 %. More importantly, taking advantage of the dynamic reversibility of coordination and thermally-activated transesterification by ZnCl2, the universal problem, i.e. the anisotropic mechanical property in 3D printing caused by printing layers, can be effectively solved, attributed to reversible rearrangement and reassociation between printing layers. Moreover, after the 3D printing products are pulverized into microparticles, the powders can be thermally compressed into new materials with a 70 % recovery in tensile strength. In addition, these powders can also be used as reinforcing fillers to enhance the virgin resin, the optimum tensile strength and elastic modulus further increase to 52 MPa and 1019 MPa by 40 % with 1 wt% dosages. Therefore, this study is a pioneering pathway for the concurrent achievement of good mechanical properties (52 MPa) and high biomass content (96 wt%) for UV-curable 3D printing photosensitive resin.

Construction of chitosan/alginate aerogels with three-dimensional hierarchical pore network structure via hydrogen bonding dissolution and covalent crosslinking synergistic strategy for thermal management systems

To replace traditional petrochemical-based thermal insulation materials, in this work, the chitosan (CHI)/alginate (ALG) (CA) aerogels with three-dimensional hierarchical pore network structure were constructed by compositing CHI and ALG using a synergistic strategy of hydrogen bonding dissolution and covalent crosslinking. The structure and properties were further regulated by crosslinking the CA aerogels with epichlorohydrin (ECH). The CA aerogels exhibited various forms of covalent crosslinking, hydrogen bonding and electrostatic interactions, with hydrogen bonding content reaching 79.12 %. The CA aerogels showed an excellent three-dimensional hierarchical pore network structure, with an average pore size minimum of 15.92 nm. The structure regulation of CA aerogels obtained excellent compressive properties, with an increase of stress and strain by 137.61 % and 45.05 %, which can support a heavy object 5000 times its weight. Additionally, CA aerogels demonstrate excellent thermal insulation properties and low thermal conductivity, comparable to commercially available insulation materials. More importantly, CA aerogels have good cyclic insulation stability and thermal properties, and they have a flame retardancy rating of V-0, which shows the stability of insulation properties and excellent safety. CA aerogels provide new ideas for the development of biomass thermal insulation materials and are expected to be candidates for thermal management applications.

Boosting antigen-specific T cell activation with lipid-stabilized protein nanoaggregates

Vaccines based on protein antigens have numerous advantages over inactivated pathogens, including easier manufacturing and improved safety. However, purified antigens are weakly immunogenic, as they lack the spatial organization and the associated ‘danger signals’ of the pathogen. Formulating vaccines as nanoparticles enhances the recognition by antigen presenting cells, boosting the cell-mediated immune response. This study describes a nano-precipitation method to obtain stable protein nanoaggregates with uniform size distribution without using covalent cross-linkers. Nanoaggregates were formed via microfluidic mixing of ovalbumin (OVA) and lipids in the presence of high methanol concentrations. A purification protocol was set up to separate the nanoaggregates from OVA and liposomes, obtained as byproducts of the mixing. The nanoaggregates were characterized in terms of morphology, ζ-potential and protein content, and their interaction with immune cells was assessed in vitro. Antigen-specific T cell activation was over 6-fold higher for nanoaggregates compared to OVA, due in part to the enhanced uptake by immune cells. Lastly, a two-dose immunization with nanoaggregates in mice induced a significant increase in OVA-specific CD8+ T splenocytes compared to soluble OVA. Overall, this work presents for the first time the microfluidic production of lipid-stabilized protein nanoaggregates and provides a proof-of-concept of their potential for vaccination.

Constructing novel GO microcomposite membranes with β-CD based microporous nanosheets for efficient dye/salt separation

Graphene oxide (GO) membrane is considered as one of the preferred choice for textile wastewater treatment thanks to its unique 2D interlayer channel features. However, GO laminar stacking is inclined to water-induced structure instability, and the narrow interlayer spacing limit mass transport efficiency, hampering its effectiveness in water treatment applications. Herein, a layer-by-layer stacked microcomposite membrane based on GO and highly microporous β-cyclodextrin based nanosheets (β-CDNS) served as intercalator was developed. The distinctive layered structure was further stabilized by covalent cross-linking with glutaraldehyde (GA). The microporous β-CDNS offered additional nanochannels that facilitated the rapid penetration of water molecules, while the abundant -OH groups provided sites for chemical cross-linking, enhancing membrane stability. The optimal GO/β-CDNS1 membrane exhibited a superior water permeance of up to 83.5 LMH/bar, with >99 % rejection for dyes such as Congo red (CR), methyl blue (MB), and chrome black T (CBT), 95.5 % for acid fuchsin (AF). Meanwhile, the GO/β-CDNS1 membrane demonstrated ultra-low (<5 %) retention for inorganic salts (MgSO4, MgCl2 and NaCl), with a separation factor as high as 194 for MB/NaCl mixtures. Therefore, employing functional interlayer nano-additives to well regulate the GO interlayer structure offers a promising guideline for developing high-performance GO-based membranes.