Search

The capsaicin analogue N -(4-hydroxy-3-methoxybenzyl) acrylamide (HMBA) was linked with polylauryl methacrylate- b -poly(2-( N , N -dimethylamino)ethyl methacrylate) (PLMA- b -PDMAEMA) via a quaternization reaction with 4-(acrylamidomethyl)-2-methoxyphenyl 2-chloroacetate (AAMPCA). The amphiphilic copolymers were capable of transforming its structure in response to the solvent change from aprotic to protic, which was verified by the 1 H NMR spectrum. The resulting cationic copolymers underwent a hydrolysis process in water, yielding zwitterionic groups on surfaces. Meanwhile, the bactericidal reagent HMBA was released. It was proved that the hydrolysis rate of the copolymers accelerated with higher temperature, higher pH value, and higher hydrophilic block units. And the controllable, sustainable release of HMBA was achieved with copolymer-mediated hydrolysis. Protein-repellent and bactericidal tests on the surface of the coating proved that antifouling and bactericidal performances of the coating correlated to the structure conversion abilities of the corresponding copolymer. The dynamic monitoring of Escherichia coli adhesion in 3 h evidenced the antifouling and bactericidal process of copolymers with different block ratios and concentrations. The coating incorporated with 3% PLMA 120 - b -(PDMAEMA-AAMPCA) 120 in polylactic acid base materials showed an adhesion ratio of E. coli less than 1% within 1 h, and the survival ratio of the adhered bacteria is <1%, suggesting its rapid speed and high efficiency in "bacterial repelling and killing". Also, the PLMA 120 - b -(PDMAEMA-AAMPCA) 120 copolymer demonstrated enhanced bactericidal ability compared with the mixture of cationic poly(laruyl methacrylate) 120 - b -poly(carboxybetaine methacrylate ester) 120 (PLMA 120 - b -PCBMAE 120 ) and free HMBA. The lowest minimal inhibitory concentration was 0.078 mg/mL against Staphylococcus aureus and 0.312 mg/mL against E. coli , respectively.

The development of nontoxic antifouling coatings in static marine environments is urgent. Herein, the successful synthesis of sulfobetaine borneol fluorinated polymers (PEASBF) by a free radical polymerization method is reported. The PEASBF coatings exhibit outstanding antifouling activity, which effectively resists the adhesion of Bovine serum albumin (FITC-BSA adhesion rate: 0.5%), Pseudomonas sp . (Biofilm: 1.3 absorbance) and Navicula sp. (Diatom attachment rate: 33%). More importantly, the PEASBF coatings display outstanding fouling release properties, achieving a release rate of 98% for Navicula sp. , and the absorbance of the Pseudomonas sp . biofilm is only 0.2 under 10 Pa shear stress. XPS and MD studies showed that the fluorinated/isobornyl groups induce more sulfobetaine groups to migrate toward polymer surfaces for intensify antifouling. Additionally, the chiral stereochemical structure of borneol enhances antifouling and fouling release ability of amphiphilic polymers. Therefore, the PEASBF has the potential for static marine antifouling applications.

The study explores the synthesis and versatile properties of amphiphilic magnetic particles (AMPs) achieved through sequential coatings. Modulating the hydrophobic content in the synthesis process allows for the formation of hydrophilic, amphiphilic, and hydrophobic magnetic particles, with stable AMPs synthesis achieved at a ratio of hydrophilic to hydrophobic portions of approximately 71 to 29%. These AMPs exhibited outstanding dispersion in both oil and water within an oil/water mixture. Polyethylenimine in the AMP primarily enhances the removal of hydrophilic microparticles and facilitates dispersion in water. On the other hand, octadecylamine is specifically designed for the effective elimination of hydrophobic microparticles and their dispersion in oil. AMPs demonstrated effective removal capabilities for both hydrophilic and hydrophobic microparticles in water as well as hydrophobic microparticles in 100% oil. Our approach is also suited for eliminating hydrophobic microparticles dispersed in small quantities of oil floating on large bodies of water in real-world situations.

The novel 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) groups immobilized on functional polymers or nanoparticles emerged as potential Pickering interfacial catalysts (PICs) for effective catalysis in biphasic systems. In this study, a snowman-shaped Janus-structured polymer with TEMPO-anchored nanohybrid particles (SM-JPP-TEMPO) was prepared and employed as a potential PIC in the Anelli-Montanari system for the selective oxidation of alcohol. The amphiphilic character of SM-JPP-TEMPO particles plays a dual role as an emulsifier and catalyst in the Pickering emulsion. As a result, it enables smaller droplets (102 μm) at the water-in-oil (W/O) interface and reduces the interfacial tension from 26.58 to 17.38 mN/m, which improves the stability of the Pickering emulsion system. This constructed Pickering emulsion microreactor offers a larger interface contact area and shortens the mass transfer distance of the substrate of cinnamyl alcohol, which significantly enhances the catalytic conversion at the Anelli-Montanari oxidation system, thus achieving remarkable conversion efficiency of (92.3%) with excellent selectivity (99%) in static (stirring-free) condition. It was found that the Janus nanohybrid catalyst (SM-JPP-TEMPO) enhanced 1.29-fold catalytic efficiency compared to the TEMPO grafted spherical polystyrene nanoparticle (PS-NPs-TEMPO) catalyst (72%). Moreover, after seven consecutive cycles, the Janus nanocatalyst (SM-JPP-TEMPO) maintained the conversion significantly. Hence, these results collectively highlight that the amphiphilic SM-JPP-TEMPO catalyst provides an efficient and eco-friendly strategy for the intensification of liquid-liquid biphasic reaction systems for potential applications in industries.

Surface passivation is key to the power conversion efficiency (PCE) of organic-inorganic lead halide perovskite solar cells (PSCs). Herein, we report a novel molecular concept of a C 2 -symmetric syn ]fluorene π-core. In addition to this bifacial amphiphilic π-core unit, triphenylamine, a well-established passivation donor, effectively passivated the PSC surface, facilitated hole transfer, and increased the maximum PCE from 18.43 to 19.74%. Another notable effect is the removal of remnant PbI b ]fluorene π-core. In addition to this bifacial amphiphilic π-core unit, triphenylamine, a well-established passivation donor, effectively passivated the PSC surface, facilitated hole transfer, and increased the maximum PCE from 18.43 to 19.74%. Another notable effect is the removal of remnant PbI 2 and the change in the perovskite orientation on the surface by the syn -type molecule. In contrast, the anti -type isomer degraded its long-term stability. We characterized the electrostatic and electronic properties of these molecules and highlighted the advantage of molecular strategy based on a bifacial structure and its stereochemistry.

Scalable assembly of nanocrystals (NCs) into two-dimensional (2D) nanosheets has aroused great interest, yet it remains under-explored. This is because current 2D assembly methods rely mainly on the use of solid- or liquid-air interfaces, which are inherently difficult for upscaling and thus lack practicability. Here, with a microemulsion-based amphiphilic assembly technique, we achieve a fast and scalable preparation of free-standing nanosheets comprising few-layer, tightly packed NCs, namely, quasi-nanosheets (quasi-NSs). Acetic acid, acting as both solvent and surface-treatment agent, is used to render the initially hydrophobic NCs amphiphilic, while simultaneously inducing the interfacial instability right after the assembly of NCs at the emulsion interface to afford quasi-NSs. This amphiphilic assembly method is applicable to a variety of NCs, and multicomponent quasi-NSs are also attainable upon coassembly of different types of NCs. In addition, the structural advantages of quasi-NSs in catalysis are showcased by using NiFe 2 O 4 quasi-NSs as electrocatalysts for the oxygen evolution reaction. This work opens a new route for the scalable construction of 2D NC sheets with designated components and functions.

Over the past few decades, extensive research efforts have been devoted to developing surfaces with unique functionalities, such as controlled wettability, antibiofouling, antifogging, and anti-icing behavior, for applications in a wide range of fields, including biomedical devices, optical instruments, microfluidics, and energy conservation and harvesting. However, many of the previously reported approaches have limitations with regard to eco-friendliness, multifunctionality, long-term stability and efficacy, and cost effectiveness. Herein, we propose a scalable bifunctional surface that simultaneously exhibits excellent antifogging and antibiofouling properties based on the synergistic integration of an eco-friendly and bio-friendly polyethylene glycol (PEG) hydrogel, oleamide (OA), and nanoscale architectures in a single flexible platform. We demonstrate that the PEG-OA-nanostructure hybrid exhibits excellent antifogging performance owing to its enhanced water absorption and spreading properties. We further show that the triple hybrid exhibits notable biofilm resistance without the use of toxic biocides or chemicals by integrating the "fouling-resistant" mechanism of the PEG hydrogel, the "fouling-release" mechanism of OA, and the "foulant-killing" mechanism of the nanostructures.

Optimizing the water bonding network in an evaporator is significant for efficient solar-driven vapor generation (SVG). Herein, we report a facile one-pot method to regulate the hydrated structure and wettability in a hierarchical porous hydrogel. An ovalbumin (OVA)-polyacrylamide hydrogel foam was fabricated in a cake-making fashion. Because of the enrichment of amphiphilic OVA at the interface, the hydrophobic walls of the air pores in the foam provide vaporization sites and help reduce parasitic heat loss, while the hydrophilic skeleton with the secondary pores effectively pumps capillary water. Notably, the proportion of intermediate water in the foam reaches 87.6% with the melting point as low as -10 °C. All these features contribute to an exceptional evaporation rate of 3.4-4.5 kg m -2 h -1 under 1 sun and robust SVG performances at high-humidity, weak sunlight, or cold weathers. The strategy of using amphiphilic molecules to optimize the hydrated structures both at the interface and in bulk promises the reasonable design of SVG materials with superior efficiency and weather adaptability.

Industrial manufacture generates a huge quantity of emulsion wastewater, which causes serious threats to the aquatic ecosystems. Water-in-oil (W/O) and oil-in-water (O/W) emulsions are two major types of emulsions discharged by industries. However, dual separation of W/O and O/W emulsions remains a challenging issue due to the contradictory permselectivity for separating the two emulsions. In the present investigation, the amphiphilicity-derived regional wetting mechanism of water and oil on the amphiphilic collagen fibers was revealed based on the combination of numerous experiments and molecular dynamics (MD) simulations. Electrostatic interactions and van der Waals force were manifested to be the driving forces of regional wetting in the hydrophilic and hydrophobic regions, respectively. The regional wetting endowed amphiphilic collagen fibers with underwater oleophobicity and underoil hydrophilicity, which enabled dual separation of emulsions by selectively retaining the dispersed water phase of W/O emulsions in the hydrophilic regions while the dispersed oil phase of O/W emulsions in the hydrophobic regions. The achieved separation efficiency was higher than 99.98%, and the flux reached 3337.6 L m -2 h -1 . Initial wetting status significantly affects the regional wetting-enabled dual separation. Based on the MD simulations, amphiphilic intramolecular conformations of tropocollagen were suggested to be the origins of regional wetting on collagen fibers. Our findings may pave the way for developing high-performance dual separation materials that are promising to be utilized for the practical treatment of emulsion wastewater.

Mechanically strong separators with good electrolyte wettability and low-shrinkage properties are desirable for highly efficient and safe lithium batteries. In this study, multifunctional nanofiber membranes are fabricated by electrospinning a homogeneous solution containing amphiphilic poly(ethylene glycol)diacrylate-grafted siloxane and polyacrylonitrile. After the chemical cross-linking of siloxane, the prepared nanofiber membranes are found to exhibit good mechanical properties, high thermostability, and superior electrolyte-philicity with aqueous and nonaqueous electrolytes. Li-metal cells with the fabricated membrane separator exhibit high cycling stability (Coulombic efficiency of 99.8% after 1000 cycles). Moreover, improved cycling stability of Li-sulfur batteries can be achieved using these membrane separators. These membrane separators can be further used in flexible aqueous lithium-ion batteries and exhibit steady electrochemistry performance. This work opens up a potential route for designing multifunctional universal separators for rechargeable batteries.

Microgel particles are cross-linked polymer networks that absorb certain liquids causing network expansion. The type of swelling fluid and extent of volume change depends on the polymer-liquid interaction and the network's cross-link density. These colloidal gels can be used to stabilize emulsion drops by adsorbing to the interface of two immiscible fluids. However, to enhance the adsorption abilities of these predominantly hydrophilic gel particles, some degree of hydrophobicity is needed. An amphiphilic Janus microgel with spatially distinct lipophilic and hydrophilic sides is desired. Here, we report the fabrication of poly(ethylene glycol) diacrylate/poly(propylene glycol) diacrylate Janus microgels (JM) using microfluidic drop making. The flow streams of the two separate and immiscible monomer solutions are brought into contact and intersected by a third immiscible fluid in a flow-focusing junction to form Janus droplets. The individual droplets are cross-linked via UV irradiation to form monodispersed microgel particles with opposing hydrophilic and hydrophobic 3D-networked polymer matrices. By combining two chemically different polymer gel networks, an amphiphilic emulsion stabilizer is formed that adsorbs to the oil-water interface while its faces absorb their respective water or hydrocarbon solvents. The resulting water-in-oil emulsions are stabilized and destabilized via a thermal-responsive hydrogel. Stimuli-responsive droplets are demonstrated by adding a short-chain oligo ethylene glycol acrylate molecule to the hydrogel formulation on the Janus microgel particle. Droplets stabilized by these particles experience a sudden increase in droplet diameter around 60 °C. This work with absorbent particles may prove useful for applications in bio catalysis, fuel production, and oil transportation.

Condensation heat transfer can be altered significantly by changing the texture and material of a surface to promote droplet removal and therefore lower thermal resistance. These designs are often expensive and fragile, however, and are fabricated using micro- or nanoscale features that are not easily implemented in real-world systems. Here, we present a novel macromachined amphiphilic surface that promotes droplet removal and resists permanent flooding via a spontaneous dewetting transition. While much of the research in condensation involves condensing on surfaces that are fully or mostly hydrophobic, droplets on the surface presented here nucleate and grow inside the structure on a hydrophilic material. The absence of any coating between the liquid and the conductive surface has the benefits of both decreasing thermal resistance and enhancing nucleation density. When the liquid grows to a critical size inside the channel, its elongated shape becomes unstable and spontaneously dewets to form rounded droplets on the hydrophobic fin peaks. The removal of liquid from the channels promotes new growth on the bare hydrophilic material, while the emerged rounded droplets can more easily shed from the hydrophobic fins. The dewetting phenomenon is shown experimentally and characterized analytically such that a desired critical water slug length could be designed by changing geometric parameters of the surface structure. The macroscale machined surface is also more durable than typical nanofabricated surfaces and easier to manufacture, making the surface more applicable to use in real-world systems. Spontaneous condensate dewetting on the amphiphilic structure is expected to enhance the study of inhibiting flooding on condensing surfaces and provide new pathways for droplet shedding techniques without a requirement for nanothin hydrophobic coatings.

Various organogel materials with either a liquid or solid surface layer have recently been designed and prepared. In this work, amphiphilic organogels (AmOG) are innovatively developed from copolymer P(PDMS-r-PEG-r-GMA) and 2,2'-diaminodiphenyldisulfide via epoxy group addition reaction and then infiltrated with amphiphilic lubricants instead of traditional hydrophilic or hydrophobic lubricants. Because of synergistic effects of hydrophilic and hydrophobic segments of amphiphilic lubricants, the AmOG surfaces showed high stability and excellent anti-icing performance. The delay in the freezing point of water was 1000 s on AmOG surfaces, which is 40 times longer as compared to the untreated hydrophilic glass surface. More importantly, low ice adhesion strength (15.1 kPa) was observed on AmOG which remained about 40 kPa even after 20 icing-deicing cycles. The novel amphiphilic organogels provide a new idea to prepare long-term anti-icing materials for practical applications.

Highly fluorescent and amphiphilic carbon quantum dots (CQDs) were prepared by microwave-assisted pyrolysis of citric acid and 4,7,10-trioxa-1,13-tridecanediamine (TTDDA), which functioned as an A 3 and B 2 polyamidation type monomer set. Gram quantities of fluorescent CQDs were easily obtained within 5 min of microwave heating using a household microwave oven. Because of the dual role of TTDDA, both as a constituting monomer and as a surface passivation agent, TTDDA-based CQDs showed a high fluorescence quantum yield of 29% and amphiphilic solubility in various polar and nonpolar solvents. These properties enable the wide application of TTDDA-based CQDs as nontoxic bioimaging agents, nanofillers for polymer composites, and down-converting layers for enhancing the efficiency of Si solar cells.

Here, a facile strategy is reported to efficiently hybridize metal nanoparticles (MNPs) with typical metal-organic frameworks (MOFs) of ZIF-8 (zeolitic imidazolate framework-8), which employs bovine serum albumin (BSA, a serum albumin protein derived from cows) as the amphiphilic stabilizer to increase the affinity of MNP toward MOFs. For instance, the as-synthesized PdNPs/ZIF-8 composites with diameter from 100 to 200 nm always maintain well-defined crystalline structure, and the PdNPs with small size of ∼2 nm are well-dispersed in the crystal of MOFs without serious aggregations due to the BSA stabilizer. In Suzuki cross-coupling reactions of aryl halide, the PdNPs/ZIF-8 as catalysts have exhibited high activity and satisfied reusability owing to the use of BSA stabilizer as well as the fixing of MOFs matrixes. In addition, the strategy also can be extended to synthesize other kinds of MNPs/MOFs hybrid composites with tunable particle size, which brings more opportunity for functional MOFs hybrid materials.

Animal cells have complicated dynamics of cell membrane structures which require desirable dyes for in vivo imaging. Here, an asymmetric amphiphilic zwitterionic perylenediimide (ZP) derivative has been constructed by introducing an octyl chain and a zwitterionic head to each imide position of perylenediimide chromophore. ZP could self-assemble into vesicles in aqueous solution. The aggregated ZP vesicles have been explored to image cell inner or surface membrane structures by a controlled disassembly process. After being taken up into cells, ZP vesicles disassemble into monomers and then incorporate into cell inner membranes. The vesicles can also disassemble in acid food and incorporate into cell surface membrane of gut cells. The research provides a new tool to label the complicated cell membrane structures with up to 3 days long-term labeling for life science applications.

We synthesized two different amphiphilic small molecules 1 and 2 by attaching the same oligo(ethylene glycol) (OEG) unit to the same dicyanodistyrylbenzene (DCS) fluorophore but at different positions. These molecules self-assemble into nanoparticles in water and show lower critical solution temperature (LCST) at 26 and 58 °C, respectively. Upon heating, the transition of hydrophilic coils to hydrophobic globules of the OEG unit leads to the change in the stacking structure of the luminescent DCS cores. As a result, it shows significant ratiometric fluorescence color changes from excimeric yellow emission to monomer-dominated green emission. Interestingly, the coassembly of 1 and 2 exhibits single transition temperature between the transition temperatures of the two components. Moreover, it is demonstrated that the transition temperature of the coassembly is delicately tuned over 26-58 °C by varying the molar mixing ratio of them.

Linear and hyperbranched poly(ethylene glycol)-cross-linked amphiphilic fluoropolymer networks comprised of different liquid crystalline comonomers were developed and evaluated as functional coatings in extreme weather-challenging conditions. Through variation of the liquid-crystalline comonomer and hydrophilic:hydrophobic component ratios, several series of coatings were synthesized and underwent a variety of analyses including differential scanning calorimetry, water contact angle measurements and solution stability studies in aqueous media. These materials maintained an unprecedented reduction in the free water melting transition (T m ) temperature across the hyperbranched and linear versions. The coatings synthesized from hyperbranched fluoropolymers preserved the liquid crystalline character of the mesogenic components, as seen by polarized optical microscopy, and demonstrated stability in saltwater aqueous environments and in cold weather conditions.

The water and small molecule uptake behavior of amphiphilic diacrylate terminated poly(dimethylsiloxane) (PDMSDA)/poly(ethylene glycol diacrylate) (PEGDA) cross-linked hydrogels were studied using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. These hydrogel networks absorbed more water as the PEGDA content of the network increased. In contrast to typical osmotic deswelling behavior that occurs when liquid water equilibrated hydrogels are immersed in small molecule solutions with water activities less than unity, water-swollen gels immersed in 2-acrylamido-2-methylpropanesulfonic acid (AMPS-H) solutions rapidly regained their water content within 4 min following an initial deswelling response. In situ ATR-FTIR analysis of the hydrogel film during the dynamic swelling experiment indicated that small molecule absorption into the gel played an important role in inducing gel reswelling in low water activity solutions. This aspect of polymer gel water uptake and interaction with small molecules is important for optimizing hydrogel coatings and hydrophilic polymer applications where there is an interaction between the internal chemical structure of the gel and electrolytes or other molecules in solution.

The phase transfer of quantum dots to water is an important aspect of preparing nanomaterials that are suitable for biological applications, and although numerous reports describe ligand exchange, very few describe efficient ligand encapsulation techniques. In this report, we not only report a new method of phase transferring quantum dots (QDs) using an amphiphilic protein (hydrophobin) but also describe the advantages of using a biological molecule with available functional groups and their use in imaging cancer cells in vivo and other imaging applications.

Herein, we present a new class of amphiphilic, thermoresponsive rod-coil conjugated block copolymer having regioregular poly(3-hexyl thiophene) and poly(N-isopropylacrylamide). Optical and luminescence properties of theses polymers significantly depend on the self-assembled nanostructures formed in different solvent and are easily tailored by chnaging the solvent composition or external stimuli like heat. Unique optical and electronic properties of this block copolymer are believed to make it promising for applications like sensor, fluorescence thermometer, optoelectronic, and bioelectronics devices.

Hydrophilic-hydrophobic-hydrophilic triblock copolymers, such as Pluronic L64, P85, and P105, have attracted more attention due to their enhancement in muscular gene delivery. In the present study, a new kind of electroneutralized triblock copolymer, LPL, dendron G2(L-lysine-Boc)-PEG2k-dendron G2(L-lysine-Boc), was designed and investigated. This hydrophobic-hydrophilic-hydrophobic copolymer is composed of a structure reverse to that of L64, one of the most effective materials for intramuscular gene delivery so far. Our results showed that LPL exhibited good in vivo biocompatibility after intramuscular and intravenous administration. LPL mediated higher reporter gene expression than L64 in assays of β-galactosidase (LacZ), luciferase, and fluorescent protein E2-Crimson. Furthermore, LPL-mediated mouse growth hormone expression significantly accelerated mouse growth within the first 10 days. Altogether, LPL-mediated gene expression in skeletal muscle exhibits the potential of successful gene therapy. The current study also presented an innovative way to design and construct new electroneutralized triblock copolymers for safe and effective intramuscular gene delivery.