Self-assembly Modification Research Articles

Dual role of triglyceride structures facilitates anti-tumor drug delivery: Both as a self-assembling module and a responsive module

Small molecule prodrugs self-assembled nano-delivery systems with tumor responsive linkages are emerging as an effective platform. However, the heterogeneity of tumor microenvironment may limit the anti-tumor effect of prodrug nanomedicines with a single response module. Here, we chose disulfide bond as the response module and branched chain alcohol as the self-assembly modification module to construct a single-responsive prodrug. We also constructed a double-responsive paclitaxel prodrug combining triglyceride and disulfide bond, taking into account of the highly expressed lipase and glutathione levels in tumor cells. The results showed that the anti-tumor effect of single-responsive branched chain alcohol modified prodrug nanoparticles was inferior to triglyceride prodrug nanoparticles with dual response modules. The triglyceride structure can not only serve as a self-assembly modification module, but also serve as a response module for intelligent drug release in tumor. Such dual roles will facilitate the efficient delivery of small molecule self-assembled prodrugs to tumor sites.

Flexible metalized polyimide nonwoven fabrics for efficient electromagnetic interference shielding

Designing and fabricating efficient electromagnetic interference shielding materials has become a significant and urgent concern. Hence, a novel lightweight and flexible metallized polyimide nonwoven fabric is successfully prepared by polydopamine roughening, palladium-free activation of chloroplatinic acid, electroless nickel plating, and octadecanethiol corrosion-resistant treatment. As a result, the efficient construction of metallized surface on polyimide fibers facilitates the formation of multiple scattering for incident electromagnetic waves, leading to an excellent electromagnetic interference performance. More importantly, the strong binding force between nickel plating and polyimide fiber substantially improves the high/low-temperature resistance, endowing the composite with excellent stability and durability in electromagnetic interference performance. Meanwhile, the self-assembly modification of octadecanethiol on the surfaces of nickel plating effectively achieves the inhibition of metal corrosion. Additionally, the high electrical conductivity of metallized polyimide nonwoven fabric endows it with a rapid-responsiveness Joule heating performance, which makes it promising to become an efficient electromagnetic interference shielding material with a distinct competitive advantage in the cold environment.

Preparation and Interfacial Analysis of Ag/Cu Coating on Acrylonitrile Butadiene Styrene Surface by Chemical Etching and Self-assembly Modification

Preparation and Interfacial Analysis of Ag/Cu Coating on Acrylonitrile Butadiene Styrene Surface by Chemical Etching and Self-assembly Modification

Mussel-inspired self-assembly platform for staged implant osseointegration: Combining early anti-infection and late osteoinduction

Current implant systems still lack the ability to combat implant-associated infections (IAI) and insufficient osseointegration to reduce the risk of implant failure. There’s an urgent need to develop an effective implant modification method to match the needs of different biological stages post-implantation, which requires anti-infection at the initial stage and osseointegration at the latter long-term stage. Here, we constructed a mussel-inspired layer-by-layer (LbL) self-assembly implant modification platform via tannic acid (TA), sequentially anchoring osteoanabolic drug (Abaloparatide, ABL) and antibacterial (Dimethylaminohexadecyl methacrylate, DMAHDM) to the Titanium (Ti) surface (Ti/ABL/DMAHDM). The Ti/ABL/DMAHDM exhibited outstanding antibacterial properties at the initial stage with an antibacterial rate of 100 % both in vitro (24 h) and in vivo (48 h). Moreover, it showed significant osteogenic induction ability at the latter long-term stage both in vitro (7 days and 14 days) and in vivo (4 weeks), accompanied by good biocompatibility. This TA-mediated self-assembly modification implants platform with staged regulation of anti-infection and osteoinduction offers potential clinical prospects for improving osseointegration after implantation.

Hysteresis-Free and Efficient Perovskite Solar Cells Using SnO2 with Self-assembly L-Cysteine Layer

Perovskite solar cells (PSCs) with SnO2 electron transport layer (ETL) still face the challenge of low efficiency with serious hysteresis due to the nonradiative recombination at the SnO2/perovskite interface. Herein, a self-assembly modification layer with multifunctional properties using L-Cysteine (Cys) is applied to solve the above issues. Through applying this novel self-monolayer between SnO2 and perovskite film, the trap state is greatly alleviated as well with an enhanced charge extraction. In addition, the naked -NH2 and sulfur atom of this monolayer will affect the crystallization dynamics of perovskite film, resulting in an improved film quality. Compared with the control device with a PCE of 18.55%, the monolayer contacts engineered device shows a significantly increase PCE over 21% along with negligible hysteresis. More interestingly, monolayer contacts engineered PSCs exhibit superior stability that over 90% of its initial PCE remains after stored at 50% relative humidity for 50 days. This work provides a promising method to fabricate planar n-i-p perovskite devices with high efficiency, stability, and repeatability.

Self-assembly of dodecyl groups on titania nanorods coated a titanium fibre for rapid and efficient solid-phase microextraction of polycyclic aromatic hydrocarbons from environment water

ABSTRACT A new organic-inorganic hybrid coated titanium fibre was developed via self-assembled modification for rapid and efficient solid-phase microextraction (SPME). Oriented titania nanorods (TiO2NRs) were in situ grown on the Ti wire as a fibre substrate through direct electrochemical anodisation. Subsequently, dodecyl groups were chemically bonded to the surface of TiO2NRs via self-assembly of n-dodecyltrimethoxysilane. The dodecyl-functionalised TiO2NRs coated Ti fibre was used to extract representative aromatic compounds coupled to high-performance liquid chromatography with UV detection. The new fibre exhibited excellent extraction efficiency and selectivity for the studied polycyclic aromatic hydrocarbons (PAHs) compared to commercial polydimethylsiloxane and polyacrylate fibres. The influential factors affecting the SPME process of PAHs were investigated and optimised. Under the optimised conditions, the developed method presented dynamic linear ranges from 0.03 to 500 μg·L−1 with correlation coefficients higher than 0.999 and limits of detection from 0.006 to 0.57 μg·L−1. Relative standard deviations (RSDs) varied between 3.51% and 4.93% and between 4.17% and 5.23% for intra-day and inter-day measurements with one single fibre, respectively. RSDs for the fibre-to-fibre reproducibility from 4.26% to 8.65% were achieved. The developed method was successfully applied to the selective preconcentration and determination of target PAHs in different environmental water samples. The relative recoveries from 89.62% to 113.1% were obtained with RSDs below 8.53%. Moreover, this fibre can be used over 200 times and fabricated in a precisely controllable manner.

Study on Graphene Oxide-Modified Polyacrylonitrile Hollow Fiber Membrane

In this paper, a multilayer diazo resin-graphene oxide/polyacrylonitrile composite membrane was prepared by layer-by-layer self-assembly and UV-induced modification of commercial polyacrylonitrile (PAN) hollow fiber membranes grafted with diazo resin (DR) and graphene oxide (GO). Scanning electron microscopy (SEM), infrared spectroscopy, contact angle, thermogravimetric analysis (TG), water flux and adsorption properties of heavy metals were studied. The results showed that diazo resin (DR) and graphene oxide (GO) were successfully grafted onto PAN membranes by layer-by-layer self-assembly. Carbonyl and carboxyl groups appeared on the surface of the modified PAN membranes; layer-by-layer self-assembly modification did not destroy the original morphology of PAN membranes, resulting in smaller pore size and higher surface roughness; hydrophilicity of the modified PAN-(DR-GO)3 membranes. The contact angle of pure water decreases from 87.8 degrees to 55.5 degrees, and the water flux increases from 733.30 g.m−1.h−1 to 1250.48 g.m−1.h−1. The thermo gravimetric curves of PAN films before and after modification did not change significantly, and the PAN films before and after modification had good thermal stability. The modified PAN membrane can achieve adsorption equilibrium in a relatively short time, and has good adsorption performance for heavy copper ions, with the adsorption rate as high as 92%.

Facile fabrication of biomimetic superoleophobic composite coating via Schiff base reaction and self-assembly

Inspired by the defects of superoleophobic surface with poor friction resistance and the complicated preparation method, the bio-dopamine was utilized and the friction-durable superoleophobic composite coating was successfully obtained via Schiff base reaction and self-assembly. Dopamine contains the phenolic hydroxyl groups that can react with an amine group or a thiol group. Polydopamine is formed via dopamine self-polymerization under aerobic and weakly alkaline conditions. Additionally, polydopamine can adhere to the surface of virtually all materials. First, the self-polymerization of folic acid induced dopamine to form polydopamine micro-nanoparticles under weakly alkaline conditions. Second, 3,5-Bis(trifluoromethyl)aniline reacted with the phenolic hydroxyl groups of polydopamine nanoparticles via Schiff base reaction. Ammonium hexafluorosilicate was adsorbed on the surface of polydopamine microspheres via electrostatic interactions. Then, the self-assembly behavior of fs-81 and fs-63 with ammonium hexafluorosilicate occurred on polydopamine nanoparticles via electrostatic interactions. Accordingly, the surface roughness was further increased, for which the limitation of traditional methods of using additional nanoparticles to construct hierarchical rough surface was broken. Eventually, the superoleophobic composite coating was applied to the surface of cotton fabric. The results showed that the contact angles of the cotton fabric surface with edible oil, ethylene glycol and glycerol were greater than 150° in the air, respectively, after two cycles of self-assembly modification. The contact angles between the cotton fabric surface and edible oil droplets were still greater than 150°after 25 mechanical abrasion cycles. In addition, the surface free energy of cotton fabric was decreased by 64.1 % after finishing the coating.

Preparation and modification of cellulose sponge and application of oil/water separation.

This work presents a facile preparation and modification of cellulose sponge with hydrophobic/oleophilic surface wetting properties. The modification method included several steps: sodium hydroxide (NaOH) and urea were introduced to dissolve cellulose, after which calcium carbonate (CaCO3) and epichlorohydrin were added into the solution for formation of a hydrogel. Finally, the cellulose sponge was obtained through hydrochloric acid (HCl) etching of CaCO3, and octadecyl trichlorosilane (OTS) self-assembly modification. The prepared cellulose sponge exhibited hydrophobicity with a water contact angle of 153.5°, and oleophilicity with an oil contact angle of 0°. The prepared cellulose sponge demonstrated a separation efficiency as high as 92% for various types of oil/water mixtures. The prepared cellulose sponge could achieve continuous separation with the assistance of a peristaltic pump. The material will be a promising candidate to be used in oil/water separation.

Synthesis of α-LiFeO2/Graphene nanocomposite via layer by layer self-assembly strategy for lithium-ion batteries with excellent electrochemical performance

As a potential alternative cathode material, α-LiFeO2 suffers a realization handicap, mainly due to its poor electrical conductivity and low lithium ion diffusion rate. In this work, we have successfully synthesized α-LiFeO2/rGO nanocomposite through a layer by layer self-assembly modification process and annealing treatment. Due to the strong electrostatic attraction between opposite charged spices, α-LiFeO2 nanoparticles were homogeneously dispersed on the graphene sheet to form a typical interconnected conducting network which was beneficial for electronic conductivity and ionic diffusivity. In comparison to pristine α-LiFeO2, the α-LiFeO2/rGO displayed an excellent electrochemical performance with average discharge capacities of 238.9, 187.2, 178.4, 121.8 and 99.5 mA h g−1 at 0.1, 0.2, 0.5, 1 and 2 C, respectively. Besides, the specific capacity retained 164.9 mA h g−1 and 107.98 mA h g−1 after 50 cycles at 0.5 C and 1 C, respectively. The remarkable progress in rate capability and cycling ability of this new nanocomposite developed a new approach to improve the electrochemical performance of α-LiFeO2.

Tailoring the selectivity of titania nanowire arrays grown on titanium fibers by self-assembled modification of trichlorophenylsilane for solid-phase microextraction of polycyclic aromatic hydrocarbons.

The authors describe TiO2 nanowires (TiO2NWs) for solid-phase microextraction of polycyclic aromatic hydrocarbons (PAHs). Well-oriented TiO2NWs were in-situ grown on a titanium wire by a hydrothermal process. The TiO2NWs arrays are radially aligned on the curved titanium fiber substrate. They possess a large surface area and are readily accessible for subsequent self-assembly of trichlorophenylsilane via formation of Ti-O-Si bonds. The TiO2NWs coated fibers show good extraction selectivity for PAHs as shown for phenathrene, fluoranthene, pyrene and benzo[a]pyrene. Following desoption by mobile phases for HPLC analysis, the PAHs were quantified by HPLC with UV detection. The improved extraction capabilities and good selectivity are explained by synergistic hydrophobic and π stacking interactions between the phenyl moieties and the PAHs. Key parameters that affect the extraction performance of the fibers were optimized. The method has a linear response in the 0.1 to 200μg·L-1 PAH concentration range. Limits of detection (at S/N = 3) range from 20 to 50ng·L-1. Relative standard deviations (RSDs) for the single fiber repeatability are less than 7.3% (n = 5) and RSDs for the fiber-to-fiber reproducibility are below 8.1% (n = 5). The method was successfully applied to the selective preconcentration and determination of trace PAHs in spiked water samples. Graphical abstract Schematic presentation of fabrication and characterization of the Ti@TiO2NWs@Phenyl fiber. PAHs: polycyclic aromatic hydrocarbons; UVFs: ultraviolet filters; PAEs: phthalate acid esters; CPs: chlorophenols.

Self-assembly modification of polyamide membrane by coating titanium dioxide nanoparticles for water treatment applications

This study modified the surface of a commercial polyamide membrane with the deposition of TiO2 nanoparticles by the self-assembly method under pressure with high permeability and photocatalytic activity. Changes in membrane characteristics and its performance for photocatalytic properties were evaluated. The results indicated that both membrane hydrophilicity and photocatalytic performance were significantly improved by the presence of TiO2 nanoparticles applied under a pressure of 1 bar. The deposition of the TiO2 particles under pressure was able to maintain the particles on the surface of the membranes and their photocatalytic capacity for three cycles of use. The prepared TiO2 photocatalytic membrane presented a great potential for wastewater treatment and for reuse wastewater systems due its ability to remove methylene blue (MB) dye solution by photocatalytic decomposition and physical separation.

Constructing zwitterionic coatings on thin-film nanofibrous composite membrane substrate for multifunctionality

In this work, we construct zwitterionic multilayers on poly(vinyl alcohol) (PVA) thin-film nanofibrous composite (TFNC) substrate via a facile surface engineered layer-by-layer (LBL) assembly of poly (sulfobetaine methacrylate) (PSBMA) and tannic acid (TA, a polyphenol), which endowed the modified membranes with multifunctionality for filtration of proteins and dyes and potential biomedical application. Characterizations of surface chemical structure and morphology of the modified membranes confirmed the successful zwitterionic self-assembly modification. The LBL-assembled membranes showed superior separation performance for filtration of proteins and dyes. Especially when the number of TA/PSBMA bilayer was 6, the PVA-6BL-M possessed high permeate flux (311.7 Lm−2 h−1) and excellent rejection (99.9%) for 0.1 g/L Direct Red 80 solution at 0.6 MPa. After being covered more TA/PSBMA bilayers, the LBL-assembled membranes could not only sieve smaller molecules of proteins and dyes well, but also exhibit better anti-biofouling properties (higher water flux recovery ratio, negligible irreversible fouling and the less BSA, E. coli and S. aureus bacteria adsorption). In addition, the LBL-assembled membranes presented excellent blood compatibility (greatly reduced platelet adhesion, significantly increased clotting time and lower hemolysis ratio), which indicated great potential for biomedical application. This work provided a facile and efficient method for designing a multifunctional TFNC membrane for water treatment and biomedical engineering.

Self-assembly modification of polyurethane sponge for application in oil/water separation.

A polyurethane (PU) sponge with excellent oil/water separation property has been successfully prepared by modifying with octadecyltrichlorosilane (OTS) self-assemblies. The chemical structure, surface topography, and surface wettability of the sponge were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and contact angle experiments, respectively. The prepared sponge could completely absorb oil within a few seconds. In addition, it also possessed excellent selectivity for oil, high absorption capacity (25 times the self-weight), high oil retention (92.6%), and good recyclability. The sponge was synthesized by a facile, mild and inexpensive method, and has excellent potential for use in practical applications because of its desirable property of oil/water separation.

An effective strategy for controlled fabrication and self-assembled modification of template-supported silica nanosheets on a superelastic nickel-titanium alloy fiber for highly efficient solid-phase microextraction

Silica nanosheets (SiO2NSs) were successfully fabricated on the superelastic nickel-titanium alloy (NiTi) wire as a novel fiber for solid-phase microextraction (SPME). Before sol-gel coating, the NiTi wire was hydrothermally treated in alkaline solution for the in situ growth of NiO/TiO2 nanosheets (NiO/TiO2NSs). The sol-gel coating of SiO2 on the surface of NiO/TiO2NSs template was investigated and a thin shell of SiO2 was found to cover NiO/TiO2NSs, which can enlarge the effective surface area of the SiO2 coating. This SiO2 capped NiO/TiO2NSs coated NiTi (NiTi@NiO/TiO2@SiO2NSs) fiber shows good extraction selectivity for polycyclic aromatic hydrocarbons (PAHs) and enhanced mechanical stability. After the self-assembled modification of SiO2NSs by phenyltrichlorosilane, the NiTi@NiO/TiO2@SiO2NSs@Ph fiber shows higher extraction capability for non-polar PAHs. Thus, the conditions for the extraction of PAHs were investigated and optimized coupled to HPLC with UV detection. Under the optimized conditions, the analytical parameters of the SPME-HPLC methods with the NiTi@NiO/TiO2@SiO2NSs and the NiTi@NiO/TiO2@SiO2NSs@Ph fibers were determined and compared. The SPME-HPLC method with the NiTi@NiO/TiO2@SiO2NSs@Ph fiber was developed for the concentration and the determination of PAHs in environment water samples. The relative recovery of PAHs in real water samples spiked at 5 μg L−1, 10 μg L−1 and 30 μg L−1 ranged from 88.1% to 109%. Furthermore, this fiber is stable due to the chemical bonding between different coatings and NiTi substrates. The fabrication of the NiO/TiO2@SiO2NSs@Ph coating on the NiTi fiber substrate is precisely controllable.

Electrophoretic deposition strategy for the fabrication of highly stable functionalized silica nanoparticle coatings onto nickel-titanium alloy wires for selective solid-phase microextraction.

A new strategy for the immobilization of phenyl-functionalized silica nanoparticles onto nickel-titanium alloy wires is presented. The homogeneous and compact silica nanoparticle coating was achieved on the hydrothermally treated nickel-titanium wires with large surface area by electrophoretic deposition, and followed by self-assembled modification of phenyltrichlorosilane. Coupled to high-performance liquid chromatography with ultraviolet detection, the extraction performance of the fabricated fiber was evaluated using typical aromatic compounds in direct-immersion mode of solid-phase microextraction. Due to its high extraction efficiency and good selectivity for ultraviolet filters, the novel fiber was employed to investigate the key factors affecting the extraction of ultraviolet filters. Under the optimized conditions, the proposed method presented linear ranges from 0.05 to 300 μg/L with correlation coefficients higher than 0.999 and limits of detection from 0.005 to 0.058 μg/L. Relative standard deviations were below 4.3 and 5.6% for intraday and interday analyses at the spiking level of 50 μg/L ultraviolet filters with the single fiber, respectively. The proposed method was successfully applied to the selective concentration and sensitive detection of target ultraviolet filters from environmental water samples. Furthermore, the developed fiber can be used at least 200 times, and fabricated in a precisely controllable manner.

Mixed surfactant systems of sucrose esters and lecithin as a synergistic approach for oil structuring

In order to modify the self-assembly of sucrose esters (SEs) in sunflower oil, we added sunflower lecithin (SFL) as co-surfactant. It is hypothesized that SFL modifies the self-assembly of SEs by interrupting the extensive hydrogen bonding between SEs monomers. The addition of SFL into SEs induced gelation of the mixed surfactant system oleogels at all studied ratios. The 7:3 SEs:SFL combination showed enhanced rheological properties compared to the other studied ratios, which suggests better molecular ordering induced by SFL. The modifications might have been caused by interference in the hydrogen bonding, connecting the polar heads of SEs molecules in the presence of SFL. This effect was confirmed by thermal behavior and small angle X-ray diffraction (SAXD) analysis. From the crystallization and melting analyses, it was shown that the peak temperature, shape and enthalpy decreased as the SFL ratio increases. Meanwhile, the bi-component oleogels exhibited new peaks in the SAXD profile, which imply a self-assembly modification. The microscopic study through polarized and electrons revealed a change in the structure. Therefore, it can be concluded that a synergistic effect between SEs and SFL, more particularly at 7:3 ratio, towards sunflower oil structuring could be obtained. These findings shed light for greater applications of SEs as structuring and carrier agent in foods and pharmaceutical.

Multiwalled carbon nanotube webs welded with Si nanoparticles as high-performance anode for lithium-ion batteries

Si nanoparticles uniformly welded in multiwalled carbon nanotube (MWCNT) webs with 20 nm carbon layer was synthesized by a layer-by-layer (LBL) self-assembled modification approach, electrostatic attraction directed self-assembly method, in-situ chemical polymerization reaction and then subsequent carbonization process. The uniform and effective carbon layer on electrode surface transmitted sufficient electrons, and the deformation pressure from charge/discharge process was buffered. The special three-dimensional framework could afford better mechanical strength to deter the fracture and pulverization of the electrode structure for repeated cycling, which helped keep the electrode integrity and improve the electric conductive network. The as-prepared electrode showed a steady reversible capacity of 1067 mAh g−1 with a fading rate of 0.066%/cycle after 200 cycles and 937 mAh g−1 with a fading rate of 0.053%/cycle over 450 cycles and high rate capability of 721 mAh g−1 at 7 A g−1.

Constructing a novel zwitterionic surface of PVDF membrane through the assembled chitosan and sodium alginate

A novel zwitterionic surface of PVDF membrane with significantly improved antifouling properties was prepared though pressure-assisted layer by layer self-assembly method based on the electrostatic interactions of chitosan (CS), sodium alginate (SA) and polyfunctional lysine. For the modified C-S-C-S-L membrane, the contact angle decreased to 35°, the bovine serum albumin (BSA) adsorption mass of static fouling on the membrane surface decreased to 10μg/cm2, and the secondary water flux recovery rate (FRR) of dynamic fouling of BSA and humic acid (HA) pollutants increased to 98% and 99%, respectively, exhibiting excellent antifouling performance. The results demonstrated that using charged bio-macromolecules and amino acids to build zwitterionic surface was effective and convenient to change the interface properties of the separation membrane through the pressure-assisted self-assembly modification method, and provided a new way for the industrial scale hydrophilic modification of hydrophobic porous membrane materials.

Preparation and Evaluation of Self-Assembled Porous Microspheres–Fibers for Removal of Bisphenol A from Aqueous Solution

A novel design of PP-g-DMAEMA/PM composite fiber as an efficient adsorbent was demonstrated by combining graft polymerization of dimethylaminoethyl methacrylate (DMAEMA) with self-assembled modification of porous microspheres (PMs) on the surface of polypropylene (PP) fiber. The structure and composition of the adsorbent was characterized by BET, XPS, FTIR, DSC, FESEM, and water angle. The kinetics and isotherm data indicated that the adsorption of bisphenol A (BPA) could be well-fitted by a pseudo-second-order kinetic model and the Langmuir isotherm, respectively. The thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process. Because of the π–π interactions and hydrogen bonds between BPA and PP-g-DMAEMA/PM, the resulting fiber obtained a higher adsorption amount (44.43 mg/g) of BPA. The presence of NaCl in the solution could facilitate the adsorption process, whereas the strong acid or strong alkali conditions and higher temperature of the solution were unfavor...