Polyelectrolytes (PEs) are polymers carrying ionizable groups along the chain backbone and play an important role in life and environmental sciences, industrial applications and other fields. Due to the complicated topological structure and electrostatic correlations of PEs, PEs exhibit very rich phase behavior and morphologies in both bulk and confined solutions. So far, many theories, simulations and machine learning approaches have been proposed to study the behavior of polyelectrolyte solutions, especially the intrinsic structure-property relationships. In this perspective, from a personal point of view, we present several recent trends in polyelectrolyte solutions. The main themes considered here are accelerated development of sequence-defined polyelectrolyte (SDPE) via artificial intelligence technology, liquid-liquid phase separation in bulk SDPE solutions, adsorption behaviors of SDPE in the vicinity of a single dielectric surface, and surface forces between two charged surfaces mediated by SDPE solutions.

The constraints of traditional 3D bioprinting are overcome by 4D bioprinting integrating with adaptable materials over time, resulting in dynamic, compliant, and functional biological structures. This innovative approach to bioprinting holds great promise for tissue engineering, regenerative medicine, and advanced drug delivery systems. 4D bioprinting is a technology that allows for the extension of 3D bioprinting technology by making predesigned structures change after they are fabricated using smart materials that can alter their characteristics via stimulus, leading to transformation in healthcare, which is able to provide precise personalized effective medical treatment without any side effects. This review article concentrates on some recent developments and applications in the field of 4D bioprinting, which can pave the way for groundbreaking advancements in biomedical sciences. 4D printing is a new chapter in bioprinting that introduces dynamism and functional living biological structures. Therefore, smart materials and sophisticated printing techniques can eliminate the challenges associated with printing complex organs and tissues. However, the problems with this process are biocompatibility, immunogenicity, and scalability, which need to be addressed. Moreover, numerous obstacles have been encountered during its widespread adoption in clinical practice. Therefore, 4D bioprinting requires improvements in future material science innovations and further development in printers and manufacturing techniques to unlock its potential for better patient care and outcomes.

The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important. This work developed the bio-based electrotechnical epoxy resins based on magnolol. High-performance epoxy resin (DGEMT) with a double crosslinked points and its composites (Al₂O₃/DGEMT) were obtained taking advantages of the two bifunctional groups (allyl and phenolic hydroxyl groups) of magnolol. Benefitting from the distinctive structure of DGEMT, the Al₂O₃/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity, high insulation, and low dielectric loss. The AC breakdown strength and thermal conductivity of Al₂O₃/DGEMT composites were 35.5 kV/mm and 1.19 W·m⁻¹·K⁻¹, respectively, which were 15.6% and 52.6% higher than those of petroleum-based composites (Al₂O₃/DGEBA). And its dielectric loss tanδ=0.0046 was 20.7% lower than that of Al₂O₃/DGEBA. Furthermore, the mechanical, thermal and processing properties of Al₂O₃/DGEMT are fully comparable to those of Al₂O₃/DGEBA. This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins, which has excellent engineering applications.

Elastomers are widely used in various fields owing to their excellent tensile properties. Recyclable and self-healing properties are key to extending the service life of elastomers. Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials. In this work, we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane (PDMS) elastomer based on the Knoevenagel condensation (KC) reaction. This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine (DMAP). The obtained PDMS elastomer exhibited an elongation at break of 266%, a tensile strength of 0.57 MPa, and a good thermal stability (T_d=357 °C). In addition, because of the presence of dynamic C＝C bonds formed by the KC reaction and low glass transition temperature (T_g=−117 °C). This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing. In addition, the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.

A series of optically active copolymers with various feed ratios have been synthesized through helix-sense-selective copolymerization catalyzed by [Rh(norbornadiene)Cl]₂-triethylamine. This process involves two proline-derived acetylene monomers, (S)-N-(4-chlorophenyl)carbamoyl-2-ethynyl pyrrolidine (MCl) and (S)-N-(tert-butoxycarbonyl)-2-ethynyl pyrrolidine, followed by acidic deprotection and neutralization. These copolymers adopt helical conformations with a preferred handedness, as demonstrated by nuclear magnetic resonance spectroscopy and a series of spectroscopic analyses. The chiroptical activity intensity of copolymer has been found to increase with MCl content. Consequently, the enantioseparation capabilities of copolymers containing 95 mol%, 90 mol%, and 85 mol% MCl units have been assessed as chiral stationary phases in high-performance liquid chromatography because of their good chiroptical activities. These chiral stationary phases effectively enantioseparate racemic alcohols, sulfoxides, amides, and metal complexes. Notably, the copolymer with 90 mol% MCl shows superior chiral recognition ability, especially for 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethanol (α=1.19) and 4-methylbenzenesulfinamide (α=1.47). Insights from molecular dynamic simulation and autodock analysis indicate that hydrogen bonding and π-π stacking interactions between the chiral stationary phases and enantiomers play a key role for successful chiral separation. Our contribution not only demonstrates the importance of hydrogen bonding donor and copolymer chiroptical activity of chiral stationary phases for chiral resolution, but will also provide valuable insights for the future development of novel stationary phases.

This study delves into the pivotal role of sulfur vulcanization in defining the mechanical characteristics of natural rubber (NR) latex-dipped products. Utilizing sulfur vulcanization, known for its operational simplicity and cost-effectiveness, we examine its ability to enhance product elasticity and mechanical strength through various sulfidic bond formations such as mono-, di-, and polysulfidic bonds. Different vulcanization systems and sulfur contents were evaluated for their influence on the mechanical attributes of latex films, employing three types of NR latex, namely concentrated NR (CNR), deproteinized NR (DPNR), and small rubber particle NR (SRP), each representing distinct non-rubber components (NRCs). The study utilized advanced atomic force microscopy (AFM) equipped with PeakForce Quantitative Nanomechanical Mapping (QNM) to visualize and measure Young's modulus distribution across the film of pre-vulcanized latex. Our findings reveal that films by CNR processed using the conventional vulcanization (CV) system exhibited enhanced tensile strength and elongation at break. It even showed a lower crosslink density than those processed using the efficient vulcanization (EV) system. Interestingly, DPNR films showed a more uniform distribution of Young's modulus, correlating well with their superior mechanical strength. In contrast, SRP films showed excessive network structure formation in the particles due to accelerated vulcanization rates, hampering subsequent post-vulcanization interparticle crosslinking in film formation and remaining more rigid. The overall results Illustrate clearly that the ultimate mechanical properties of the latex films are strongly dependent on the type of sulfidic bonds formed. This research reveals further the very intricate relationship between the vulcanization methods, sulfur content, and latex type in optimizing the mechanical performance of NR latex products. It provides valuable insights for industry practices aimed at improving the quality and performance of latex-dipped goods.

Some novel manganese and nickel complexes were synthesized by reacting manganese(II) dichloride and nickel(II) dichloride with pyridyl-imine ligands differing in the nature of the substituents at the imino nitrogen atom. All the complexes were characterized by analytical and infrared data: for some of them single crystals were obtained, and their molecular structure was determined by X-ray diffraction. The complexes were used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene obtaining active and selective catalysts giving predominantly 1,2 polybutadiene in case of manganese catalysts and exclusively cis-1,4 polybutadiene in case of nickel catalysts.

Although Ziegler-Natta (Z-N) polyolefins have been widely used as raw materials to produce pharmaceutical or food packaging, the migration of acid scavengers, an additive usually introduced in Z-N polyolefins, from the packaging to its contents has not been reported. In this work, the migration of the two most used acid scavengers, calcium stearate (CaSt₂) and zinc stearate (ZnSt₂), from a Z-N polypropylene random copolymer (PPR) into water during autoclaving at 121 °C were comparatively investigated. It was found that, for PPR plates containing 0.1 wt% CaSt₂ or ZnSt₂ (PPR-0.1CaSt₂, PPR-0.1ZnSt₂, respectively), the concentration of migrated calcium ion into water increased with autoclaving time, while that of zinc ion was much lower at same treatment durations and did not show a significant increase with treatment time. Interestingly, after removing all plates and acidification treatment, a considerable amount of stearic acid was detected in sterilized water for PPR-0.1ZnSt₂, but no such significant stearic acid was detected in sterilized water for PPR-0.1CaSt₂. Based on the structural evolution of the two soaps upon heating, possible mechanisms for the different migration behavior of CaSt₂ and ZnSt₂ from PPR into water during autoclaving treatment were proposed. Our results suggest that the migration issue of acid scavengers is worthy of attention in pharmaceutical packaging materials produced from Z-N polyolefins.

The present study presents an assessment of the interrelations between long-chain branching, specific nucleation, and end-use properties of polypropylene blends: blends of linear polypropylene (L-PP) and long-chain branched polypropylene (LCB-PP) modified by a specific β-nucleating agent (NA). Specimens with various LCB-PP compositions with and without NA were prepared under complex flow fields by injection molding. Wide-angle X-ray scattering was employed to capture the X-ray patterns of both the skin and core of the specimens, determining the overall crystallinity and amounts of individual polymorphs. The increasing content of LCB-PP and γ-phase, at the same time, in the blends is reflected in both increasing crystallinity and improved mechanical properties, namely, yield stress and Young’s modulus. On the other hand, the composition of the blends had no significant effect on the impact strength, except for nucleated L-PP. It has been demonstrated that adding a relatively small amount of LCB-PP is sufficient to modify the mechanical properties of linear polypropylene. Even a very small amount of LCB-PP in the L-PP suppressed the effectiveness of NA.

The alternating copolymer of CO₂ with epoxide is a green plastic that can efficiently transform CO₂ into valuable chemicals. Despite the significant advances made, the restricted practical application of CO₂-sourced polycarbonates due to their lack of functionality has hindered field development. We successfully demonstrated the flame retardancy of poly(chloropropylene carbonate) (PCPC), a perfectly alternating copolymer of epichlorohydrin (ECH) and CO₂. This was prepared at a 200-gram scale using a high-efficacy tetranuclear organoborane catalyst. PCPC’s excellent flame-retardant performance has been proven by both the vertical combustion test (UL94 V-0) and the limiting oxygen index (LOI) value (29.1%). The underlaid flame-retardant mechanism of PCPC was clearly elucidated. As a result, we confirmed that the generated cyclic carbonates and concurrently released flame-retardant chlorine radicals, hydrogen chloride, and CO₂ during combustion render PCPC an excellent flame retardant. Furthermore, we investigated the practicability of PCPC as a halogen-rich polymeric flame retardant by blending it with commercial bisphenol A polycarbonate (BPA-PC). PCPC upgraded the flame retardancy rating of BPA polycarbonate from V-2 to V-0 even with a mere 1 wt% addition. It is our hope that this result will prove useful in future developments of advanced CO₂-sourced polymeric materials.

Porous phase-inversion membranes of complex morphology were obtained on the basis of aromatic polyamidoimides with different numbers of hydroxyl groups in the diamine component of the repeating unit. The influence of the quality of the precipitant (nonsolvent) applied in membrane preparation (i.e., the use of “strong” or “weak” nonsolvent) on structural and morphological features of polymer membranes of various chemical compositions was studied. Investigation of dilute solutions of membrane-forming polymers by optical methods revealed the changes in the state of the system both in the presence of a solvent and in the presence of a nonsolvent. On the basis of the obtained results, it was possible to estimate the sensitivity of the studied polymer/solvent/nonsolvent system to changes in the copolymer composition (a number of hydroxyl groups in the repeating unit).

Amphiphilic asymmetric brush copolymers (AABCs) possess unique self-assembly behaviors owing to their asymmetric brush architecture and multiple functionalities of multicomponent side chains. However, the synthesis of AABCs presents challenges, which greatly limits the exploration of their self-assembly behaviors. In this work, we employed dissipative particle dynamics (DPD) simulations to investigate the self-assembly behaviors of AABCs in selective solution. By varying the copolymer concentration and structure, we conducted the self-assembly phase diagrams of AABCs, revealing complex morphologies such as channelized micelles with one or more solvophilic channels. Moreover, the number, surface area, and one-dimensional density distribution of the channelized micelles were calculated to demonstrate the internal structure and morphological transformation during the self-assembly process. Our findings indicate that the morphology of the internal solvophilic channels is greatly influenced by the copolymer structure, concentration, and interaction parameters between the different side chains. The simulation results are consistent with available experimental observations, which can offer theoretical insights into the self-assembly of AABCs.

The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing. Based on the above background, a novel heterocyclic para-aramid nanofiber/reduced graphene oxide (HPAN/rGO) composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying. The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals, and a through-well structure of directed microchannels in the direction parallel to the temperature gradient. By varying the mass ratio of HPAN/rGO, a composite aerogel with an ultra-low density of 5.34−7.81 mg·cm⁻³ and an ultra-high porosity of 98%−99% was obtained. Benefiting from the anisotropic structure, the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m⁻¹·K⁻¹, respectively. A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels. Moreover, due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer, the composite aerogel also exhibits excellent flame retardancy properties, and its total heat release rate (THR) was only 5.8 kJ·g⁻¹, which is far superior to many reported aerogels. Therefore, ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.

Long-chain polyamides (LCPAs) are a class of bio-based polymers that can bridge conventional polyolefins and polycondensates. In this work, taking the advantage of the amphiphilic nature of polyamide 1012 (PA1012), membranes were prepared by using a non-conventional phase separation approach, namely, mixed ‘non-solvents’ evaporation induced phase separation (MNEIPS). PA1012 can be dissolved in a mixture of polar and non-polar solvents, both of which are non-solvents of PA1012. During the sequential evaporation of the two solvents, the phase separation of PA1012 occurred, inducing the formation of porous structures. We investigated the process of membrane formation in detail, with a specific focus on the liquid-liquid and liquid-solid phase transitions involved. Moreover, we studied the influence of critical factors, such as polymer concentration and mixed-solvent ratio, on the morphologies and properties of PA1012 membranes. This study provides new insights into the development of porous materials based on long-chain polycondensates.

The construction of monodisperse microporous organic microspheres is deemed a challenging issue, primarily due to the difficulty in achieving both high microporosity and uniformity within the microspheres. In this study, a series of fluorinated monodisperse microporous microspheres are fabricated by solvothermal precipitation polymerization. The resulting fluorous methacrylate-based microspheres achieved higher than 400 m²/g surface area, along with a yield of over 90% for the microspheres. Through comprehensive characterization and simulation methods, we discovered that the introduction of fluorous methacrylate monomers at high loading levels is the key factor contributing to the formation of the microporosity within the microspheres. The controlled temperature profile was found to be advantageous for achieving a high yield of microspheres and increased uniformity. Two-dimensional assemblies of these fluorinated microsphere arrays exhibited superhydrophobicity, superolephilicity, and water sliding angles below 10°. Furthermore, a three-dimensional assembly of the fluorinated microporous microsphere in a chromatographic column demonstrated significant improvement in the separation of Engelhardt agent compared to commercial columns. Our work offers a novel approach to constructing fluorinated monodisperse microporous microspheres for advanced applications.

Solid-state electrolytes are considered to be the vital part of the next-generation solid-state batteries (SSBs), due to their high safety and long operation life span. However, the two major factors that impede the expected performance of batteries are: the easy formation of lithium dendrites due to the concentration gradient of anions, and the low ionic conductivity at room temperature, which prevents reaching ideal electrochemical performance. Single-ion quasi-solid-state electrolytes (SIQSSEs) could provide higher safety and energy density, owing to absence of anion concentration gradient and solvent, as well as good lithium-ion transport ability. The porous covalent organic frameworks (COFs) are beneficial for con-structing appropriate lithium-ion transport pathway, due to the ordered 1D channel. In addition, the boroxine COFs (COF-5) offers strong ability of withdrawing anion part of lithium salt. Last but not the least, boron atom could play the role of coordinate site due to its electron deficiency. These advantages afford an opportunity to obtain a SIQSSE with high ionic conductivity and high lithium transference number (LTN) simultaneously. The COF-5 based SIQSSEs delivered a high ionic conductivity of 6.3×10⁻⁴ S·cm⁻¹, with a high LTN of 0.92 and a wide electrochemical stable window (ESW) of 4.7 V at room temperature. The LiFePO₄ (LFP)/Li cells, which was assembled with COF-5 based SIQSSE, exhibited outstanding long cycle stability, high initial capacity and favorable rate performance. The results indicated COFs could be an ideal material for single-ion solid-state electrolytes in next-generation batteries.

In this work, a morphology transition mode is revealed in ultra-high molecular weight polyethylene (UHMWPE) when stretching at 120 °C: moving from the slightly deformed region to the necked region, the morphology transfers from small spherulites to a mixture of transcrystalline and enlarged spherulites, and finally to pure transcrystalline; meanwhile, the lamellae making up the transcrystalline or spherulite were fragmented into smaller ones; spatial scan by wide-angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS) revealed that the crystallinity is increased from 25.3% to 30.1% and the crystal orientation was enhanced greatly, but the lamellae orientation was quite weak. The rise of enlarged spherulites or a mixture of transcrystalline and spherulites can also be found in UHMWPE stretched at 140 and 148 °C, whereas absent in UHMWPE stretched at 30 °C. In situ WAXS/SAXS measurements suggest that during stretching at 30 °C, the crystallinity is reduced drastically, and a few voids are formed as the size increases from 50 nm to 210 nm; during stretching at 120 °C, the crystallinity is reduced only slightly, and the kinking of lamellae occurs at large Hencky strain; during stretching at 140 and 148 °C, an increase in crystallinity with stretching strain can be found, and the lamellae are also kinked. Taking the microstructure and morphology transition into consideration, a mesoscale morphology transition mode is proposed, in the stretching-induced crystallization the fragmented lamellae can be rearranged into new supra-structures such as spherulite or transcrystalline during hot stretching.

In this study, a novel cost-effective methodology was developed to enhance the gas barrier properties and permselectivity of unfilled natural rubber (NR)/polybutadiene rubber (BR) composites through the construction of a heterogeneous structure using pre-vulcanized powder rubber to replace traditional fillers. The matrix material is composed of a blend of NR and BR, which is widely used in tire manufacturing. By incorporating pre-vulcanized trans-1,4-poly(isoprene-co-butadiene) (TBIR) rubber powder (pVTPR) with different cross-linking densities and contents, significant improvements in the gas barrier properties and CO₂ permselectivity of the NR/BR/pVTPR composites were observed. The results indicated that compared to NR/BR/TBIR composites prepared through direct blending of NR, BR, and TBIR, the NR/BR/pVTPR composites exhibited markedly superior gas barrier properties. Increasing the cross-linking density of pVTPR resulted in progressive enhancement of the gas barrier properties of the NR/BR/pVTPR composite. For example, the addition of 20 phr pVTPR with a cross-linking density of 346 mol/m³ resulted in a 79% improvement in the oxygen barrier property of NR/BR/pVTPR compared to NR/BR, achieving a value of 5.47×10⁻¹⁴ cm³·cm·cm⁻²·s⁻¹·Pa⁻¹. Similarly, the nitrogen barrier property improved by 76% compared to NR/BR, reaching 2.4×10⁻¹⁴ cm³·cm·cm⁻²·s⁻¹·Pa⁻¹, which is 28 % higher than the conventional inner liner material brominated butyl rubber (BIIR, P_N2=3.32×10⁻¹⁴ cm³·cm·cm⁻²·s⁻¹·Pa⁻¹). Owing to its low cost, exceptional gas barrier properties, superior adhesion to various tire components, and co-vulcanization capabilities, the NR/BR/pVTPR composite has emerged as a promising alternative to butyl rubber in the inner liner of tires. Furthermore, by fine-tuning the cross-linking density of pVTPR, the high-gas-barrier NR/BR/pVTPR composites also demonstrated remarkable CO₂ permselectivity, with a CO₂/N₂ selectivity of 61.4 and a CO₂/O₂ selectivity of 26.12. This innovation provides a novel strategy for CO₂ capture and separation, with potential applications in future environmental and industrial processes. The multifunctional NR/BR/pVTPR composite, with its superior gas barrier properties and CO₂ permselectivity, is expected to contribute to the development of safer, greener, and more cost-effective transportation solutions.

The addition of nanoparticles serves as an effective reinforcement strategy for polymeric coatings, utilizing their unique characteristics as well as extraordinary mechanical, thermal, and electrical properties. The exceptionally high surface-to-volume ratio of nanoparticles imparts remarkable reinforcing potentials, yet it simultaneously gives rise to a prevalent tendency for nanoparticles to agglomerate into clusters within nanocomposites. The agglomeration behavior of the nanoparticles is predominantly influenced by their distinct microstructures and varied weight concentrations. This study investigated the synergistic effects of nanoparticle geometric shape and weight concentration on the dispersion characteristics of nanoparticles and the physical-mechanical performances of nano-reinforced epoxy coatings. Three carbon-based nanoparticles, nanodiamonds (NDs), carbon nanotubes (CNTs), and graphenes (GNPs), were incorporated into epoxy coatings at three weight concentrations (0.5%, 1.0%, and 2.0%). The experimental findings reveal that epoxy coatings reinforced with NDs demonstrated the most homogenous dispersion characteristics, lowest viscosity, and reduced porosity among all the nanoparticles, which could be attributed to the spherical geometry shape. Due to the superior physical properties, ND-reinforced nanocomposites displayed the highest abrasion resistance and tensile properties. Specifically, the 1.0wt% ND-reinforced nanocomposites exhibited 60%, 52%, and 97% improvements in mass lost, tensile strength, and failure strain, respectively, compared to pure epoxy. Furthermore, the representative volume element (RVE) modeling was employed to validate the experimental results, while highlighting the critical role of nanoparticle agglomeration, orientation, and the presence of voids on the mechanical properties of the nanocomposites. Nano-reinforced epoxy coatings with enhanced mechanical properties are well-suited for application in protective coatings for pipelines, industrial equipment, and automotive parts, where high wear resistance is essential.

The conformational and dynamical properties of a long semi-flexible active polymer chain confined in a circular cavity are studied by using Langevin dynamics simulation method. Results show that the steady radius of gyration of the polymer decreases monotonically with increasing the active force. Interestingly, the polymer forms stable compact spiral with directional rotation at the steady state when the active force is large. Both the radius of gyration and the angular velocity of the spiral are nearly independent of the cavity size, but show scaling relations with the active force and the polymer length. It is further found that the formation of the stable compact spiral in most cases is a two-step relaxation process, where the polymer first forms a metastable swelling quasi spiral and then transforms into the stable compacted spiral near the wall of the cavity. The relaxation time is mainly determined by the transformation of the swelling quasi spiral, and shows remarkable dependence on the size of the cavity. Specially, when the circumference of the circular is nearly equivalent to the polymer length, it is difficult for the polymer to form the compacted spiral, leading to a large relaxation time. The underlying mechanism of the formation of the compacted spiral is revealed.

Membrane fusion is essential for many cellular physiological functions, which is modulated by highly precise molecular mechanism involving multiple energy barriers. Nanoparticles (NPs), which exhibit immense potential in the field of biomedical applications, can act as fusogen proteins to initiate and regulate membrane fusion. However, the underlying mechanisms of NP-induced membrane fusion and the molecular details involved remain largely elusive. Here, using coarse-grained molecular dynamics simulations, we systematically investigate the NP-induced membrane fusion behaviors and the influences of NP properties (size, hydrophobicity and hydrophilicity). Our results show that the vesicle-bilayer fusion induced by a hydrophobic NP is an intricately state-wise process, involving the approach and local deformation of the vesicle and bilayer bridging by the NP, the flip-flop of lipids from proximal leaflets and the formation of a fusion stalk, as well as further lipid interactions between distal leaflets and complete fusion. Moreover, we find that NP properties have distinct effects on membrane fusion and thus the optimal NP conditions for facilitating membrane fusion are obtained. Our work provides a mechanistic understanding of NP-induced membrane fusion and offers useful insights for efficient and controlled regulation of membrane fusion.