Construction and Properties of O/W Liquid Crystal Nanoemulsion.

Liquid crystal emulsion is a new type of emulsion, in which the emulsifier molecules are located at the oil/water (O/W) interface and form a long-range ordered and short-range disordered lamellar liquid crystal. The lamellar liquid crystal formed by the emulsifier is similar to the skin stratum corneum lipid structure, which enables it to have a broad application prospect in the fields of cosmetics, pharmaceuticals, etc. In this work, a liquid crystal nanoemulsion was obtained by passing a liquid crystal emulsion stabilized by hydrogenated lecithin and phytosterol combination through a microfluidizer. The microstructure of the prepared liquid crystal nanoemulsion was investigated experimentally by dynamic light scattering, transmission electron microscopy, and small-angle X-ray scattering. The results have shown that the nanoemulsion inherited the liquid crystal emulsion property, namely, the long-range ordered and short-range disordered lamellar structure still existed at the oil/water interface even though they underwent extrusion, friction, and acceleration. At the same time, the underlying mechanisms of the existence of lamellar liquid crystal between the oil phase and the water phase for the nanoemulsion were explored theoretically by molecular dynamics simulations. The simulation results elucidated that the hydrogenated lecithin and phytosterol combination improved the flexibility of the bilayer structure composed of emulsifiers. The bilayers were the basic structure units of lamellar liquid crystals, and thus, the improved flexibility of bilayers provided insurance for the existence of lamellar liquid crystals with larger curvature around the oil droplets. In addition, the applicable properties of liquid crystal nanoemulsion were studied, and the results have shown that the liquid crystal nanoemulsion presented better slow-release and moisturizing properties than traditional nanoemulsions due to the existence of multilayers between oil and water phases. This work not only provides necessary information for the development and effective application of liquid crystal emulsions but also is helpful for in-depth understanding the inner properties of lamellar liquid crystal at molecular level.

Unraveling the Molecular Mechanisms of Alcohol-Mediated Skin Permeation Enhancement: Insights from Molecular Dynamics Simulations.

The application of alcohols as permeation enhancers in pharmaceutical and cosmetic formulations has attracted considerable attention, owing to their skin permeation-enhancing effect. Nonetheless, the elucidation of the fundamental mechanisms underlying the skin permeation-enhancing effect remains elusive. In this study, molecular dynamics (MD) simulations were employed to investigate the effect of 1,2-propanediol (1,2-PDO), 1,2-butanediol (1,2-BDO), and ethanol (EtOH) on the stratum corneum (SC) model membrane. The results showed that the effect of alcohols on the SC model membrane displayed a concentration-dependent nature. The alcohols can interact with SC lipids and exhibit a remarkable ability to selectively extract free fatty acid (FFA) molecules from the SC model membrane and make the SC looser. Meanwhile, 1,2-BDO and EtOH can penetrate into SC lipid bilayers at higher concentrations, leading to the formation of continuous hydrophilic defects in SC. The FFA extraction and the formation of continuous hydrophilic defects induced ceramide (CER) tail chains to become more disordered and fluid and also weakened the hydrogen bonding (H-bonding) network among SC lipids. Both the FFA extraction and the continuous hydrophilic defect formation endowed alcohols with the permeation-enhancing effect. The constrained simulations revealed that the free energy barriers decreased for the permeation of the hydrophilic model molecule (COL) across the SC model membranes containing alcohols, particularly for 1,2-BDO and EtOH. The possible permeation-enhancing mechanisms of alcohols were proposed correspondingly. This work not only provided a deep understanding of the transdermal permeation-enhancing behavior of alcohols at the molecular level but also provided necessary reference information for designing effective transdermal drug delivery systems in applications.

A Cellulose Reinforced Multifunctional Binder for High-Performance Silicon Anodes.

Silicon (Si) has garnered significant interest as a potential anode material for next-generation lithium-ion batteries due to its high theoretical capacity. However, Si anodes suffer from substantial volume expansion during the charge and discharge processes, which severely undermines their cycling stability. To address this issue, developing novel binders has become an effective strategy to suppress the volume expansion of Si anodes. In this study, a multifunctional polymer binder (DCCS) was designed by the cross-linking of dialdehyde cellulose nanocrystal (DACNC) and carboxymethyl chitosan (CMCS), which forms a 3D network structure via Schiff-base bonds. The DCCS binder with abundant chemical and hydroxyl bonds shows strong adhesion between Si nanoparticles and current collectors, thus enhancing the mechanical properties of the electrode. Furthermore, the DACNC also served as the protecting buffer layer to release the inner stress and stabilize the solid electrolyte interface (SEI). At 4 A g-1, the resulting Si@25%DCCS electrode demonstrated a capacity of 1637 mAh g-1 after 500 cycles, with an average capacity fading rate of 0.07% per cycle. Therefore, this multifunctional binder is considered a promising binder for high-performance Si anodes.

The effects of adsorbed benzo(a)pyrene on dynamic behavior of polystyrene nanoplastics through phospholipid membrane: A molecular simulation study.

Nanoplastics (NPs) are mainly generated from the decomposition of plastic waste and industrial production, which have attracted much attention due to the potential risk for humans. The ability of NPs to penetrate different biological barriers has been proved, but the understanding of molecular details is very limited, especially for organic pollutant-NP combinations. Here, we investigated the uptake process of polystyrene NPs (PSNPs) combined with benzo(a)pyrene (BAP) molecules by dipalmitoylphosphatidylcholine (DPPC) bilayers by molecular dynamics (MD) simulations. The results showed that the PSNPs can adsorb and accumulate BAP molecules in water phase and then carried BAP molecules to enter DPPC bilayers. At the same time, the adsorbed BAP promoted the penetration of PSNPs into DPPC bilayers effectively by hydrophobic effect. The process of BAP-PSNP combinations penetrating into DPPC bilayers can be summarized into four steps including adhesion on the DPPC bilayer surface, uptake by the DPPC bilayer, BAP molecules detached from the PSNPs, and the PSNPs depolymerized in the bilayer interior. Furthermore, the amount of adsorbed BAP on PSNPs affected the properties of DPPC bilayers directly, especially the fluidity of DPPC bilayers that determine the physiologic function. Obviously, the combined effect of PSNPs and BAP enhanced the cytotoxicity. This work not only presented a vivid transmembrane process of BAP-PSNP combinations and revealed the nature of the effects of adsorbed benzo(a)pyrene on the dynamic behavior of polystyrene nanoplastics through phospholipid membrane, but also provide some necessary information of the potential damage for organic pollutant-nanoplastic combinations on human health at a molecular level.

The effects of size and surface functionalization of polystyrene nanoplastics on stratum corneum model membranes: An experimental and computational study.

Nanoplastics are mainly generated from the decomposition of plastic waste and artificial production and have attracted much attention due to their wide distribution in the environment and the potential risk for humans. As the largest organ of the human body, the skin is inevitably in contact with nanoplastics. Stratum corneum is the first barrier when the skin is exposed to nanoplastics. However, little is known about the interactions between nanoplastics and stratum corneum. Here, the effects of particle size and surface functionalization (amino-modified and carboxy-modified) of polystyrene nanoplastics on the stratum corneum models were studied by Langmuir monolayer and molecular dynamics simulations. An equimolar mixture of ceramide/cholesterol/free fatty acid was used to mimic stratum corneum intercellular lipids. The Langmuir monolayer studies demonstrated that the larger size and surface functionalization of polystyrene nanoplastics significantly reduced the stability of stratum corneum lipid monolayer in a concentration-dependent fashion. Simulation results elucidated that functionalized polystyrene oligomers had a stronger interaction with lipid components of the stratum corneum model membrane. The cell experiments also indicated that functionalized polystyrene nanoplastics, especially for amino-modified polystyrene nanoplastics, had significant cytotoxicity on normal human dermal fibroblast cells. Our results provide fundamental information and the basis for a deeper understanding of the health risks of nanoplastics to humans.

pH and light dual stimuli-responses of mixed system of 2-hydroxyl-propanediyl-α,ω-bis(dimethyldodecyl ammonium bromide) and trans-ortho-hydroxyl cinnamic acid.

Stimuli-responsive smart supramolecular self-assembly with controllable morphology and adjustable rheological property has attracted widespread concern of scientists in recent years due to the great potential application in microfluidics, controlled release, biosensors and so on. In this study, a pH and UV light dual stimuli-responsive system was constructed by combining Gemini surfactant 2-hydroxyl-propanediyl-α,ω-bis(dimethyldodecyl ammonium bromide) (12-3(OH)-12·2Br-) with trans-ortho-hydroxyl cinnamic acid (trans-OHCA) in aqueous solution. The phase behavior and stimuli-responsive behavior of the system including the microstructural transition, rheological property, intermolecular interaction, and isomerization reaction were explored by various experiment techniques such as rheometer, UV-vis spectrum, polarized optical microscopy (POM), transmission electron microscopy (TEM), dynamic light scattering (DLS) as well as theoretical calculation. The system displays abundant phase behaviors that supramolecular self-assemblies of different morphologies in different states such as spherical micelle, wormlike micelle, lamellar liquid crystal, and aqueous two phase system (ATPS) were observed even at lower concentration, which provide the research basis on the abundant stimuli-responsiveness of the system. The results prove that the multiple ionization and the photo-isomerization of trans-OHCA endow the system with plentiful responses to pH and UV light stimuli. It is expected that this study on the dual stimuli-responsive system with abundant self-assembly behaviors and adjustable rheological behaviors would be of theoretical and practical importance, which would provide essential guidance in designing and constructing smart materials with multiple stimuli-responses.

Indocyanine Green Performance Enhanced System for Potent Photothermal Treatment of Bacterial Infection.

The instability in solution and aggregation-induced self-quenching of indocyanine green (ICG) have weakened its fluorescence and photothermal properties, thus inhibiting its application in practice. In this study, the cationic and anionic liposomes containing ICG were prepared based on 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-glycerol (DPPG), respectively. Molecular dynamics (MD) simulations demonstrate that ICG molecules are better distributed in the membranes of cationic DOTAP-based liposomes, leading to a superior fluorescence and photothermal performance. The liposomal ICG also shows the physical and photothermal stability during irradiation and long-term storage. On this basis, the prepared DOTAP-based liposomal ICG was encapsulated in the self-healing hydrogel formed by guar gum through the borate/diol interaction. The proposed liposomal ICG-loaded hydrogel can not only convert near-infrared (NIR) light into heat effectively but also repair itself without external assistance, which will realize potent photothermal therapy (PTT) against bacterial infection and provide the possibility for meeting the rapidly growing needs of modern medicine.

Study on the Liquid-Liquid and Liquid-Solid Interfacial Behavior of Functionalized Graphene Oxide.

With the rise of carbon neutrality, the applications of carbon-based materials are gaining considerable attention. Graphene oxide (GO) is a two-dimensional sheet with epoxy and hydroxyl groups on the basal plane and carboxyl groups at the edge. In order to change the oil/water (o/w) interfacial activity, GO was controlled and modified by dodecylamine to get two kinds of functionalized GOs (fGOs), named as basal plane-functionalized GO (bGO) and edge-functionalized GO (eGO), respectively. The interfacial tension measurement showed that fGOs could reduce more interfacial tension at the poly-α-olefin/water interface than those at synthetic esters or aromatic compounds/water interfaces. Besides, eGO can reduce more poly-α-olefin-4/water interfacial tension compared to bGO. The interfacial dilatational rheology of eGO and fatty alcohol polyoxyethylene ether-4 (MOA4) showed that MOA4 gradually replaced eGO at the interface with the increase of MOA4, until the interface was completely occupied. eGO and MOA4 complex emulsion exhibited the best friction-reducing performance at 250 rpm. The coefficient of friction (COF) curves of the emulsions with eGO showed two platforms, with the COF reduced by 37.42% at the most. The rheological results of emulsions showed that the addition of eGO increased the elasticity of the emulsion. Emulsions showed shear-thinning and friction-thickening properties, which make it easier for the emulsion to form a lubricating film on the metal surface. Our research results suggested that the functionalization on the edge of GO will change the interfacial properties significantly, which have widespread applications in the encapsulation of active materials, surface protection, adsorption, and separation of pollutants.

Flow effects on the surface properties of surfactant foam films.

The surface electrostatic properties of liquid foam, involving the electrokinetic (EK) phenomena in the liquid-gas interface, have significant effects on the stability of the foam. Here, we established a theoretical model for ion transport in liquid films by combining the liquid flow and surface reaction. We found that the surface electrostatic properties of liquid foams were influenced unexpectedly by the pressure-induced flow. The liquid flow will induce the potential and concentration differences in the flow direction. When the pressure drop increases to a certain high value, the induced potential and salt concentration difference increases, leading to the change of the surface electrostatic properties such as zeta potential and the surface charge density. This change shows that the surface electrostatic properties of foam films depend on the coupling of various factors including ion distribution and pressure drop, which deepens our understanding of the electrostatic properties of the foam films.

A novel drug delivery system -- Drug crystallization encapsulated liquid crystal emulsion.

Liquid crystals (LCs) are widely used for drug delivery due to their controlled and sustained drug release properties. In this paper, drug crystallization encapsulated liquid crystal emulsion, a novel drug delivery system, was proposed. The lamellar liquid crystals formed by hydrogenated lecithin, which are similar to the skin stratum corneum lipid structure, are adopted as the drug carrier to encapsulate non-steroidal anti-inflammatory drugs (NSAIDs). As the model drug, ketoprofen exists in the hydrophobic core of emulsion as a drug crystal when squalane is used as the oil phase. The microstructure, sustained drug release behaviors, physicochemical property and biocompatibility of the system were examined by polarized light microscopy, rheological measurements, differential scanning calorimetry, X-ray diffraction, small-angle X-ray scattering, in vitro release study, and in vitro cellular cytotoxicity assay. The results have shown that the novel system lowers the drug crystal melting point and improves the thermal stability of liquid crystal structure. Besides, the excellent biocompatibility and sustained release property through the additional dissolution step of drug crystal show its application potentials in the topical cosmeceuticals. The results will also be helpful for in-depth understanding of the physical state of encapsulated drug in the liquid crystal carrier systems.

Effect of the Substituent Position on the Phase Behavior and Photoresponsive Dynamic Behavior of Mixed Systems of a Gemini Surfactant and trans-Methoxy Sodium Cinnamates.

Mixed systems of the Gemini cationic surfactant trimethylene-1,3-bis (dodecyldimethylammonium bromide) (12-3-12·2Br-) and the photosensitive additives trans-methoxy sodium cinnamates with different substituent positions (trans-ortho-methoxy cinnamate, trans-OMCA; trans-meta-methoxy cinnamate, trans-MMCA; and trans-para-methoxy cinnamate, trans-PMCA) were selected for investigating the effects of the substituting position of methoxy on the system phase diagram and UV light-responsive behavior of the wormlike micelles. The differences in phase behaviors of the selected systems were analyzed by calculating the potential distribution, molecular volume, and free energy of solvation of cinnamates and the binding energies between photosensitive additives and the surfactant. The photoresponsive behaviors of wormlike micelle solutions formed in the selected systems were studied by the rheological method and UV-vis and H nuclear magnetic resonance (1H NMR) spectroscopy; the kinetics of photoisomerization of trans-OMCA, trans-MMCA, and trans-PMCA were studied by first-order derivative spectrophotometry. The results reveal that the methoxy substituent position has a great influence on the phase behavior and photosensitivity of the studied systems. In addition, the photoisomerization of the studied cinnamates follows the first-order opposite reaction laws; the different reaction rates play the decisive role in the photosensitivity of the wormlike micelles. This paper would afford a deeper understanding of the UV light-responsive mechanism at the molecular level and provide essential guidance in preparing smart materials with adjustable light sensitivity.

Molecular Dynamics Simulations and Density Functional Theory on Unraveling Photoresponsive Behavior of Wormlike Micelles Constructed by 12-2-12·2Br- and trans-ortho-Methoxy Cinnamate.

Photoresponsive systems with controllable self-assembly morphologies and adjustable rheological properties have attracted widespread interest by researchers in the past few years. Among them, the photoresponsive systems consisting of ortho-methoxycinnamic (OMCA) and Gemini surfactants are endowed with rich self-assemblies with different states and in different scales including spherical micelles, wormlike micelles, vesicles, aqueous two-phase system (ATPS), etc. All these self-assemblies display excellent photoresponsive behavior. However, the mechanism of these photoresponsive behaviors has not been unraveled systematically so far. In this study, molecular dynamics (MD) simulations, density functional theory (DFT) calculations, transmission electron microscopy, and rheology are employed to investigate the photoresponsive behaviors of wormlike micelles caused by photoisomerization of trans-OMCA in 12-2-12·2Br-/trans-OMCA solutions and to unravel the underlying mechanisms of these photoresponsive behaviors. The experimental results show that 12-2-12·2Br-/trans-OMCA micelles display photoresponsiveness after UV-light irradiation, with the transformation of micellar morphologies from wormlike micelle to spherical micelles. In MD simulations, certain micelle morphologies in experiments and the specific packing between 12-2-12·2Br-/OMCA were successfully captured. The larger three-dimensional structure and steric hindrance of cis-OMCA disturb the interior structure of micelles. The stronger hydrophilicity of cis-OMCA induces the escape of cis-OMCA from the interval of micelles to the solution. The energy results prove that trans-OMCA associates more strongly with 12-2-12·2Br- than cis-OMCA. These causes lead to the fission and repacking of wormlike micelles.

Understanding surface charge regulation in silica nanopores.

Nanoporous silica is used in a wide variety of applications, ranging from bioanalytical tools and materials for energy storage and conversion as well as separation devices. The surface charge density of nanopores is not easily measured by experiment yet plays a vital role in the performance and functioning of silica nanopores. Herein, we report a theoretical model to describe charge regulation in silica nanopores by combining the surface-reaction model and the classical density functional theory (CDFT). The theoretical predictions provide quantitative insights into the effects of pH, electrolyte concentration, and pore size on the surface charge density and electric double layer structure. With a fixed pore size, the surface charge density increases with both pH and the bulk salt concentration similar to that for an open surface. At fixed pH and salt concentration, the surface charge density rises with the pore size until it reaches the bulk asymptotic value when the surface interactions become negligible. At high pH, the surface charge density is mainly determined by the ratio of the Debye screening length to the pore size (λD/D).

Real-time monitoring of the effect of carbon nanoparticles on the surface behavior of DPPC/DPPG Langmuir monolayer.

Air pollution has become increasingly serious. Fine particulate matter (PM2.5) is the most well-known air pollutant, which leads to some common respiratory diseases when inhaled into the lungs to certain concentration. However, there is a lack of research on the process of dynamically monitoring the real-time effect of nanoparticles on the pulmonary surfactant monolayer. In this study, the DPPC/DPPG monolayer is prepared by the Langmuir method to simulate the lung surfactant monolayer during respiration and the carbon nanoparticles are introduced to the monolayer under different surface pressures to simulate the real dynamic process of inhaling nanoparticles during breathing. The effect of carbon nanoparticles on the surface behavior of DPPC/DPPG monolayer in real-time was examined in details by a combination of surface pressure (π)-area (A) isotherms, compressibility modulus (Cs-1)-surface pressure (π) isotherms and the Brewster angle microscopy (BAM). The results have shown that the introduction of carbon nanoparticles under different surface pressures affects the properties of lipid monolayers. The added carbon nanoparticles under lower surface pressure are easy to penetrate the lipid molecules to inhibit monolayer phase transition. When the carbon nanoparticles are introduced to the monolayer under higher surface pressure, they tend to self-aggregate to reduce the monolayer stability rather than interact with lipid tail chains. This work not only confirms the exotic hydrophobic carbon nanoparticles retain in the DPPC/DPPG monolayer irreversibly and affect the surface behavior of monolayer during respiration, but also opens a new idea for real-time monitoring of the effects of PM2.5 on lung health.

Investigation of Drug for Pulmonary Administration-Model Pulmonary Surfactant Monolayer Interactions Using Langmuir-Blodgett Monolayer and Molecular Dynamics Simulation: A Case Study of Ketoprofen.

Pulmonary administration is widely used for the treatment of lung diseases. The interaction between drug molecules and pulmonary surfactants affects the efficacy of the drug directly. The location and distribution of drug molecules in a model pulmonary surfactant monolayer under different surface pressures can provide vivid information on the interaction between drug molecules and pulmonary surfactants during the pulmonary administration. Ketoprofen is a nonsteroidal anti-inflammatory drug for pulmonary administration. The effect of ketoprofen molecules on the lipid monolayer containing 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-glycerol (DPPG) is studied by surface pressure (π)-area (A) isotherms and compressibility modulus (Cs-1)-surface pressure (π) isotherms. The location and distribution of ketoprofen molecules in a lipid monolayer under different surface pressures are explored by surface tension, density profile, radial distribution function (RDF), and the potential of mean force (PMF) simulated by molecular dynamics (MD) simulation. The introduction of ketoprofen molecules affects the properties of DPPC/DPPG monolayers and the location and distribution of ketoprofen molecules in monolayers with various surface pressures. The existence of ketoprofen molecules hinders the formation of liquid-condensed (LC) films and decreases the compressibility of DPPC/DPPG monolayers. The location and distribution of ketoprofen molecules in the lipid monolayer are affected by cation-π interaction between the choline group of lipids and the benzene ring of ketoprofen, the steric hindrance of the lipid head groups, and the hydrophobicity of ketoprofen molecule itself, comprehensively. The contact state of lipid head group with water is determined by surface pressure, which affects the interaction between drug molecules and lipids and further dominates the location and distribution of ketoprofen in the lipid monolayer. This work confirms that ketoprofen molecules can affect the property and the inner structure of DPPC/DPPG monolayers during breathing. Furthermore, the results obtained using a mixed monolayer containing two major pulmonary surfactants DPPC/DPPG and ketoprofen molecules will be helpful for the in-depth understanding of the mechanism of inhaled administration therapy.

Photoresponsive Behavior of Wormlike Micelles Constructed by Gemini Surfactant 12-3-12·2Br- and Different Cinnamate Derivatives.

The photoresponsive wormlike micelles constructed by Gemini surfactants and cinnamate derivatives play a great role in the field of smart materials. However, how the structure of cinnamate derivatives affects the photoresponsive behavior of micelles is still a hotspot for scientists to research. Here, three kinds of aromatic salts with different ortho-substituted groups including trans- o-methoxy cinnamate ( trans-OMCA), trans- o-hydroxy cinnamate ( trans-OHCA), and trans-cinnamate ( trans-CA) were introduced into Gemini surfactant 12-3-12·2Br- aqueous solutions to construct photoresponsive wormlike micelles through their noncovalent interactions. Their properties were researched using the rheological method, cryo-transmission electron microscopy, and 1H NMR and two-dimensional nuclear Overhauser effect spectra. The results show that these cinnamate derivatives could well construct wormlike micelles with 12-3-12·2Br-. Furthermore, subtle differences in the ortho substituents' structure have a significant effect on the photoresponsive behavior of formed wormlike micelles. Specifically, the zero viscosity (η0) of 40 mM 12-3-12·2Br-/24 mM trans-OHCA mixed solution decreases from 26.72 to 2.6 Pa·s with the shortening of the length of wormlike micelles after UV irradiation. Correspondingly, the η0 for the same ratio of 12-3-12·2Br-/ trans-OMCA decreases from 2.42 to 0.06 Pa·s and the wormlike micelles are transited into rodlike micelles and even spherical micelles after the same UV irradiation time. However, the variation of wormlike micelles in the 12-3-12·2Br-/ trans-CA system induced by UV light is not obvious with η0 being maintained at around 2.89 Pa·s. This study will help us better understand the effects of chemical groups on macrophenomena and microinteraction for micellar systems. It provides a theoretical basis for the construction of photoresponsive micelles, thus widening their application in the field of soft materials.

Ionic Liquid-Polypyrrole-Gold Composites as Enhanced Enzyme Immobilization Platforms for Hydrogen Peroxide Sensing.

In this work, three different aqueous solutions containing imidazole-based ILs with different alkyl chain lengths ([Cnmim]Br, n = 2, 6, 12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [C12mim]Br-PPy (C12-PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, C12-PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained C12-PPy-Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel C12-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared C12-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.

Predicting the capacitance of carbon-based electric double layer capacitors by machine learning.

Machine learning (ML) methods were applied to predict the capacitance of carbon-based supercapacitors. Hundreds of published experimental datasets are collected for training ML models to identify the relative importance of seven electrode features. This present method could be used to predict and screen better carbon electrode materials.

Toxicant Deposition and Transport in Alveolus: A Classical Density Functional Prediction.

The deposition and transport of toxicants on pulmonary surfactant are important processes in human health and medical care. We have introduced classical density functional theory (CDFT) to provide insight into this process. Nine typical toxicants in PM2.5 were considered, and their free energy and structural information have been examined. The free energy profile indicates that PbO, As2O3, and CdO are the three toxicants most easily deposited in the pulmonary alveolus, which is consistent with survey data. CuO appears to be the easiest toxicant to transport through the surfactant. Structural analysis indicates that the toxicants tend to pass through the surfactant with rotation. The configuration of the pulmonary surfactant was examined by extending our previous work to polymer systems, and it appears that both the configurational entropy and the direct interaction between the surfactant and the toxicant dominate the configuration of the pulmonary surfactant.

UV-Responsive Behavior of Multistate and Multiscale Self-Assemblies Constructed by Gemini Surfactant 12-3-12·2Br- and trans- o-Methoxy-cinnamate.

Photoresponsive systems with adjustable self-assembly morphologies and tunable rheological properties have aroused widespread concern of researchers in recent years because of their prospect applications in controlled release, microfluidics, sensors, and so forth. In this paper, we combine a cationic Gemini surfactant 12-3-12·2Br- and trans-2-methoxy-cinnamate ( trans-OMCA) together to create a representative UV-responsive self-assembly system. The system displays abundant self-assembly behaviors, and the self-assemblies with different states and different scales including wormlike micelles, vesicles, and lyotropic liquid crystals (LCs) as well as an aqueous two-phase system (ATPS) are observed even at lower surfactant concentration. The UV-responsive behavior of the formed self-assemblies is investigated systematically. The results have shown that the photoisomerization of OMCA from trans form to cis form under UV light irradiation alters the hydrophobicity and steric hindrance effect of OMCA and thus affects the molecular packing at the micellar interface and further leads to the transformation of assembly morphologies. The long wormlike micelles can gradually transform into much shorter rodlike micelles under UV irradiation and companied by the decrease of solution viscosity by 2 orders of magnitude. In addition, the vesicles can evolve into multistate self-assembly structures including the ATPS, wormlike micelles, rod-like micelles, and small spherical micelles depending on the UV irradiation time. The ATPS and its adjacent anisotropic LC phase can respectively combine into a single phase and separate into ATPS under UV irradiation. The morphologies of assemblies in the 12-3-12·2Br-/ trans-OMCA mixed system can be tailored by adjusting the system composition and duration of UV light irradiation on purpose. The photoresponsive system with abundant self-assembly behaviors and tunable rheological properties has wide application prospect in numerous fields such as drug delivery, materials science, smart fluids, and so forth, and the macroscopic phase separation and combination provide novel strategies for effective separation and purification of certain substances.