Hydrophilic Functionalization Research Articles

Versatile Dehydration-Assisted Functionalization of Quantum Dots and Rods.

Functionalization of quantum dots (QDs) and quantum rods (QRs) with ligands is essential for their further practical application across various domains. Dehydration-assisted functionalization (DAF) is a versatile method applicable to a wide range of hydrophilic ligands with an affinity to the surface of QDs and QRs. This approach facilitates rapid one-pot ligand exchange and dense modification by efficiently transferring these ligands onto the surface of QDs and QRs. This study demonstrates the efficacy of DAF in preparing chiral QRs, engineering the surface charge of QDs, utilizing QR aggregates, and conjugating dense DNA onto cadmium-free InP/ZnS QDs. DAF therefore offers a versatile solution for hydrophilic ligand functionalization of QDs and QRs applicable to diverse applications.

Surface-modified microchip electrophoretic separation and analysis of functional components in health care products

Microchip electrophoresis (MCE) is widely applied in food, environment, medicine, and other fields, owing to its high separation efficiency, low consumption of reagents and samples, and ease of integrating multiple operating units. Polymer microchip materials like cycloolefin copolymer (COC) are low-cost and easy to fabricate. However, their practical applications are limited by the non-specific adsorption on channel surface during electrophoresis and the instability of electroosmotic flow. These shortcomings can be solved by COC surface modification. In this study, a static coating and dynamic/static coating combined strategy was used to develop a channel-surface-modified COC microchip. Combined with laser-induced fluorescence (LIF) detection, a MCE-LIF separation and analysis method was developed for detecting functional components in health care products. The separation performance of MCE was improved by the static coating microchannel surface modification method. The static coating was constructed by hydrophobic amino acid adsorption, glutaraldehyde immobilization, and hydrophilic amino acid functionalization on the COC microchannel surface. The separation performance of MCE was improved by microchannel surface modification combined with dynamic/static coating. The static coating was constructed by valine adsorption, carboxyl activation, and ethylenediamine functionalization on the COC microchannel surface. The dynamic coating is automatically formed by introducing a buffer solution containing hydroxypropyl methylcellulose and sodium dodecyl sulfate into the microchannel. The physical and chemical properties of surface-modified microchannels and the factors governing electrophoretic separation were studied. Combined with LIF detection, the MCE-LIF separation and analysis of lysine and γ-aminobutyric acid present in children's health care products, as well as aspartic acid and taurine in sport drinks, were developed. The recoveries of lysine and γ-aminobutyric acid in children's health care products were 84.8%-118%, and the relative standard deviations (RSDs) were less than 7.2% (n=3). The recoveries of aspartic acid and taurine in sport drinks were 97.5%-118%, and the RSDs were less than 6.4% (n=3). The analysis results are consistent with the HPLC results, and the method has potential for application in the separation and analysis of anionic amino acids in health care products.

Hydrophilic functionalization of rhodium metallene for saving-energy hydrogen production and sulfur recovery

The use of thermodynamically more favorable sulfion oxidation reaction (SOR) to replace sluggish oxygen evolution reaction is an effective method for energy-saving production of hydrogen. Herein, we propose the synthesis of organic–inorganic hybrid through the modification of 1-hydroxyethylidene-1,1-diphosphonic acid on Rh metallene (HEDP-Rh metallene) as a bifunctional electrocatalyst for hydrogen evolution reaction (HER) and SOR. The modification of hydrophilic HEDP can effectively promote the water adsorption, thereby accelerating the mass/electron transfer at the interface. The HEDP-Rh metallene requires low overpotentials of 30 mV at 10 mA cm−2 for HER and 0.538 V at 100 mA cm−2 for SOR. In HER-SOR coupled reaction, HEDP-Rh metallene drives the current density of 100 mA cm−2 at 1.08 V for concurrent production of hydrogen and sulfur, highlighting energy-efficient hydrogen production and sulfur recycle.

Preparation, acidolysis kinetics and scale inhibition performance of low molecular weight poly(maleic anhydride‐alt‐vinyl acetate) based on self‐stabilized precipitation polymerization

AbstractPoly(maleic anhydride‐alt‐vinyl acetate) (PMV) is used as a fine chemical in the field of biomedical. However, the techniques of PMV preparation have shortcomings like limited yield (Yp), complex post‐treatment and toxic solvents. Herein self‐stabilized precipitation (2SP) technique which possessed advantages of simple operation and post‐processing, non‐toxic solvent, and surface‐cleaned product is adopted to synthesize low number‐average molecular weight (Mn) PMV by tune‐up of reaction parameters. PMV with Mn of 2800–39,200 g/mol are successfully achieved. Furthermore, acidolysis kinetics of PMV is investigated centering on effects of Mn, acidolysis temperature, and initial concentration. All samples can undergo completely ring‐opening and the equilibrium pH of acidolyzed PMV is related to initial concentration irrelevant to Mn and temperature. Carboxylic degree (CD) varying rate and time of reaching equilibrium pH and 100% CD are impacted by Mn and temperature irrelevant to initial concentration. Finally, scale inhibition effectiveness of PMV with 2800 g/mol can be up to 53.69%, larger than that of commercial citric acid by about three times. This contribution supplies an easily operational and eco‐friendly process to obtain low molecular weight PMV which can be the scale inhibitor for industry and daily life, providing the quantization basis for hydrophilic functionalization of PMV.

Design and assembly of Ag-decorated Bi2O3 @ 3D MXene Schottky heterojunction for the highly permeable and multiple-antifouling of fibrous membrane in the purification of complex emulsified oil pollutants

Membrane separation technology has potential for purifying emulsified oily wastewater. However, the oils, soluble organic substances, and microorganisms can cause complex membrane fouling problems, thereby reducing the separation efficiency and service life. Herein, a highly permeable and multiple-antifouling composite membrane was prepared using porous PAN fibrous mat as support backbone for the assembly of Ag-decorated Bi2O3 @ 3D MXene Schottky heterojunction and hydrophilic TA as the adhesive. The unique arrangement of 3D MXene heterojunction and hydrophilic functionalization effectively broke through the limitation of separation flux and synergistically enhanced the anti-fouling performance of membrane. Such fibrous composite membrane achieved an exceedingly high permeability (2717–3328 L·m−2·h−1) for various emulsified oils, while ensuring excellent oil/water emulsion retention rate (99.59%) and good cycle stability. Meanwhile, the composite membrane displayed favorable photocatalytic degradation performance toward degrading MeB (96.1%) and antibacterial ability. Furthermore, the MD simulation and free radical trapping experiments were carried out to unravel the molecular interactions during the separation process and the photocatalytic mechanism of composite membrane, respectively. Overall, the combination of photocatalytic self-cleaning, anti-oil adhesion, and antibacterial effect renders the membrane high permeability and multiple-antifouling performance, which provides a new strategy for dealing with complex oily wastewater in petrochemical industry.

Functionalized carbon nanocones performance in water harvesting.

In this work, we investigate the water capture process for functionalized carbon nanocones (CNCs) through molecular dynamic simulations in the following three scenarios: a single CNC in contact with a reservoir containing liquid water, a single CNC in contact with a water vapor reservoir, and a combination of more than one CNC in contact with vapor. We found that water flows through the nanocones when in contact with the liquid reservoir if the nanocone tip presents hydrophilic functionalization. In contact with steam, we observed the formation of droplets at the base of the nanocone only when hydrophilic functionalization is present. Then, water flows through in a linear manner, a process that is more efficient than that in the liquid reservoir regime. The scalability of the process is tested by analyzing the water flow through more than one nanocone. The results suggest that the distance between the nanocones is a fundamental ingredient for the efficiency of water harvesting.

Impact of hydrophilic bamboo cellulose functionalization on electrospun polyacrylonitrile nanofiber-based humidity sensors

Impact of hydrophilic bamboo cellulose functionalization on electrospun polyacrylonitrile nanofiber-based humidity sensors

Superhydrophilic 2D Carbon Nitrides Prepared by Direct Chemical Vapor Deposition

Surface wetting greatly impacts the performances of many photocatalysts in a water/humid‐involved medium. Carbon nitrides and its isotopes, as emerging metal‐free low‐cost photocatalysts for water splitting, usually require strong chemical or irradiation treatments to obtain highly hydrophilic surfaces, which can undermine their photocatalytic performances. Herein, an alternative method for the direct synthesis of superhydrophilic carbon nitride thin films (CN x , x ≈ 0.86–1.04) and graphitic carbon nitride powder (g‐C3N4) by using chemical vapor deposition is proposed. Less than 5° contact angle with water is accessible on both the surface of the as‐grown CN x thin films and the membranes made from the g‐C3N4 powder. It is found that the remarkable wetting property can be attributed to the spontaneous hydrophilic functionalization group (e.g., –OH, –NO x , = O) supplied by a constant multielemental air flow. The abundant CN triple bonds also promote needle‐shaped nanostructures on the 2D surfaces, which enhances their chemical wettability. Finally, the tremendous potential of this novel technique for direct synthesis of superhydrophilic carbon nitride in photocatalysis applications is demonstrated.

Small-Scale Robotics with Tailored Wettability.

Small-scale robots (SSRs) have emerged as promising and versatile tools in various biomedical, sensing, decontamination, and manipulation applications, as they are uniquely capable of performing tasks at small length scales. With the miniaturization of robots from the macroscale to millimeter-, micrometer-, and nanometer-scales, the viscous and surface forces, namely adhesive forces and surface tension have become dominant. These forces significantly impact motion efficiency. Surface engineering of robots with both hydrophilic and hydrophobic functionalization presents a brand-new pathway to overcome motion resistance and enhance the ability to target and regulate robots for various tasks. This review focuses on the current progress and future perspectives of SSRs with hydrophilic and hydrophobic modifications (including both tethered and untethered robots). The study emphasizes the distinct advantages of SSRs, such as improved maneuverability and reduced drag forces, and outlines their potential applications. With continued innovation, rational surface engineering is expected to endow SSRs with exceptional mobility and functionality, which can broaden their applications, enhance their penetration depth, reduce surface fouling, and inhibit bacterial adhesion.

Effect of functionalized and unfunctionalized basic oxygen steelmaking slag on the growth of cereal wheat (Triticum aestivum)

The continued growth of the steel industry poses concerns for the health of the planet and the health of the environment. The waste produced by the steel industry is an untapped resource that is not used nearly as much as it should be. The potential of using basic oxygen steelmaking slag (BOS) as a fertilizer was tested on cereal wheat plants' growth, with samples that are both hydrophobic and hydrophilic through functionalization. Parameters tested included: mass gain, height grown (cm), germination rate (GR), mean germination time (MGT) and a composite visual score (CVS). The results found that the BOS slag improved the growth of the samples due to the high amount of Ca and Fe provided to the sample. It was proposed that the improved performance of hydrophobically functionalized slag over those with hydrophilic functionalization was due to the water reservoir created around the seed. Lanolin functionalized samples are the optimum fertilizer in this study, providing the optimum conditions for nutrient transfer to the seed samples.

Encapsulation of Hydrophobic Porphyrins into Biocompatible Nanoparticles: An Easy Way to Benefit of Their Two-Photon Phototherapeutic Effect without Hydrophilic Functionalization.

Simple SummaryEfficient photosensitizers for photodyanmic therapy (PDT) need to be soluble in physiologic media. This requirement often complicates significantly the chemical access to such compounds, resulting in lower availability and higher production costs for the best representatives. Given that their screening and selection is often initially conducted in organic media from series of hydrophobic model compounds, the possibility to use directly such hydrophobic photosensitizers in real PDT studies was highly desirable to speed up their definitive identification but also to alleviate their cost. In this respect, PMLABe polymeric nanoparticles (NPs) were presently probed as nanocarriers to water-solubilize hydophobic star-shaped porphyrin-based which turned out to be promising oxygen photosensitizers for theranostic approaches. We show here that PDT conducted using such NPs loaded with these compounds is as efficient than when functional hydrosoluble analogues of these photosensitiers are tested alone and that tracking of the photosensitizer by fluorescence imaging is even easier.Star-shaped hydrophobic porphyrins, acting as powerful fluorescent two-photon photosensitizers for oxygen in organic solvents, can easily be loaded into PMLABe polymeric nanoparticles at various concentrations. In this contribution, the performance of these porphyrin-containing nanoparticles in terms of photodynamic therapy (PDT) is compared to those of the corresponding water-soluble porphyrin analogues when irradiated in MCF-7 cancer cells. While quite promising results are obtained for performing PDT with these nanoparticles, validating this approach as a mean for using more easily accessible and less expensive photosensitizers, from a synthetic perspective, we also show that their luminescence can still be used for bioimaging purposes in spite of their confinement in the nanoparticles, validating also the use of these nano-objects for theranostic purposes.

Robust Zn anode enabled by a hydrophilic adhesive coating for long-life zinc-ion hybrid supercapacitors

Artificial polymer coating on Zn metal anode is an available strategy to address a series of notorious parasitic side reactions at Zn anode/aqueous electrolyte in aqueous Zn-based electrochemical devices. However, most hydrophilic polymer layers suffer from risks of being dissolved in aqueous electrolyte during long-term cycle process. The traditional coatings with strong adhesion to metal are often hydrophobic which intensely increase the interfacial resistance at Zn electrode/aqueous electrolyte and further restrain the interfacial ion transportation/migration. In this study, a hydrophilic adhesive coating (HAC) with proportionally distributed amides and acrylates is designed to circumvent this hydrophilicity/adhesion trade-off. The layer shows great ion-regulating capability in Zn2+ plating/stripping, thanks to the evenly distributed abundant carbonyl adsorption sites at the molecular level. Benefiting from the hydrophilic nature and long-lasting adhesion of the coating to the electrode, the HAC-modified Zn-Zn symmetric cell is able to deliver a long cycle life of 880 h at 5 mA cm−2/5 mAh cm−2, compared to 20 h for Bare Zn. The Zn-Ti asymmetric cell also exhibits excellent reversibility with an average coulombic efficiency of 97.6% after 200 cycles at 5 mA cm−2. The HAC-modified Zn-AC ion hybrid supercapacitor retains 100% of the initial capacity for a long life of 14,000 cycles. This hydrophilic functionalization of hydrophobic coating provides new design strategies and prospects for Zn anode artificial interface towards practically useful zinc-ion energy storage devices.

Functionalized Graphene Platforms for Anticancer Drug Delivery.

Two-dimensional nanomaterials are emerging as promising candidates for a wide range of biomedical applications including tissue engineering, biosensing, pathogen incapacitation, wound healing, and gene and drug delivery. Graphene, due to its high surface area, photothermal property, high loading capacity, and efficient cellular uptake, is at the forefront of these materials and plays a key role in this multidisciplinary research field. Poor water dispersibility and low functionality of graphene, however, hamper its hybridization into new nanostructures for future nanomedicine. Functionalization of graphene, either by covalent or non-covalent methods, is the most useful strategy to improve its dispersion in water and functionality as well as processability into new materials and devices. In this review, recent advances in functionalization of graphene derivatives by different (macro)molecules for future biomedical applications are reported and explained. In particular, hydrophilic functionalization of graphene and graphene oxide (GO) to improve their water dispersibility and physicochemical properties is discussed. We have focused on the anticancer drug delivery of polyfunctional graphene sheets.

Hydrophilic Surface Functionalization of Electrospun Nanofibrous Scaffolds in Tissue Engineering.

Electrospun polymer nanofibers have received much attention in tissue engineering due to their valuable properties such as biocompatibility, biodegradation ability, appropriate mechanical properties, and, most importantly, fibrous structure, which resembles the morphology of extracellular matrix (ECM) proteins. However, they are usually hydrophobic and suffer from a lack of bioactive molecules, which provide good cell adhesion to the scaffold surface. Post-electrospinning surface functionalization allows overcoming these limitations through polar groups covalent incorporation to the fibers surface, with subsequent functionalization with biologically active molecules or direct deposition of the biomolecule solution. Hydrophilic surface functionalization methods are classified into chemical approaches, including wet chemical functionalization and covalent grafting, a physiochemical approach with the use of a plasma treatment, and a physical approach that might be divided into physical adsorption and layer-by-layer assembly. This review discusses the state-of-the-art of hydrophilic surface functionalization strategies of electrospun nanofibers for tissue engineering applications. We highlighted the major advantages and drawbacks of each method, at the same time, pointing out future perspectives and solutions in the hydrophilic functionalization strategies.

Comparison study on chelated and non-chelated titanate functionalized graphene nanosheets for enhancement of waterborne alkyd anticorrosion coating

Hydrophilic functionalization of reduced graphene (RGOs) is able to improve its dispersibility in aqueous polymer. However, the influence of hydrophilic segments on the chemical resistance of RGOs/polymer nanocomposites keeps indistinct. Here, we prepared RGOs functionalized with hydrophilic chelated titanate (TA) and non-chelated titanate (T), named as TARGOs and TRGOs, respectively. The intercalation reaction mechanism between titanate and GO was elucidated. The presence of hydrophilic triethanolamine in titanate had little impact on the structural disorder of RGOs, but can effectively improve the exfoliation degree and the dispersibility of functionalized RGOs in waterborne alkyd resin (WAAR). The water resistance and thermal stability of TARGOs/WAAR were inferior to that of TRGOs/WAAR. The initial impedance modulus and coating resistance of TARGOs/WAAR were higher than TRGOs/WAAR at the same RGOs content when the RGOs content is 0.5% owing to the more homogeneous distribution of TARGOs in WAAR. However, the corrosion resistance of TARGOs/WAAR significantly decreased when the TARGOs content increased to 0.7%, which can be attributed to the presence of hydrophilic regions. In contrast, TRGOs/WAAR displayed the optimum long-term corrosion resistance when the TRGOs content was 0.7%, even though the dispersion of TRGOs in WAAR cannot be comparable to TARGOs in WAAR.

Surface hydrophilization of highly porous poly(ether imide) microparticles by covalent attachment of poly(vinyl pyrrolidone)

The realization of a permanent surface hydrophilization for highly porous microparticles designed for removing uremic toxins from the blood of renal failure patients, without altering their complex pore structure, represents a challenging task.Here we report on the hydrophilic surface functionalization of porous poly (ether imide) (PEI) microparticles, having a mean diameter of 226 ± 14 μm, a porosity of around 84 ± 2% with a mean pore diameter of 230 ± 40 nm, by covalent attachment of amino-terminated poly (vinyl pyrrolidone) (PVP–NH2) with a number average molecular weight of Mn = 5400 g mol−1. X-ray photoelectron spectroscopy confirmed a successful surface modification by a change in the surface chemistry, in particular the N/C ratio. The PEI-PVP particles exhibited an advancing water contact angle of θadv = 75° ± 5° as determined in environmental scanning electron microscopy microwetting experiments. The obtained results from mercury intrusion porosimetry and nitrogen adsorption experiments documented the preservation of the porous structure of the particles in the cause of the modification, which could be visualized by electron microscopy. The presented approach enables a covalent hydrophilization of porous particles while preserving their nanoporous morphology.

An Optimized Strategy for Self-Assembly of Carbon Nanotubes Arrays: From the Perspective of Molecular Dynamics Simulation and Experiments

Hydrophilic/hydrophobic self-assembly has been recognized as one of the effective strategies for assembling carbon nanotubes (CNTs) arrays, but it takes a long time to accomplish this task. So since the emergence of this method, scientists have been exploring how to shorten the assembly process. Meanwhile, up to now, little progress has been made on the mechanism of patterned self-assembly of CNTs. In this paper, in view of the proposal that the assembly of CNTs is able to be accomplished only by hydrophilic functionalization of the substrate, the feasibility of this scheme is verified by molecular dynamics simulation and experiments. Specifically speaking, single-walled carbon nanotubes (SWNTs) with better properties are taken as the research object, and the morphology of surfactant molecule on the surface of SWNTs after non-covalent modification, the optimal model of hydrophilic functionalized substrates (H-substrates) and the morphological changes after the interaction between modified SWNTs (M-SWNTs) and H-substrates are studied by molecular dynamics simulation. At the same time, experiments corresponding to the simulation steps are carried out. The results show that only hydrophilic functionalization of the substrate can also complete the assembly of CNTs, in which the electrostatic attraction between surfactant molecules and H-substrates is the driving force for self-assembly of SWNTs onto hydrophilic surface, and intervention of H2O molecules between M-SWNTs and bare SiO2 substrates is the main reason why SWNTs cannot be assembled onto bare SiO2 surface. The results provide an optimization strategy for the fabrication of CNTs arrays based on self-assembly method.

Hydrophilic and antibacterial surface functionalization of polyamide fabric by coating with polylysine biomolecule

Polyamide (PA) fiber is the second largest synthetic fiber, and extensively applied in underwear, outerwear, sports/leisure wear and decorative fabrics. However, PA textiles have poor wearing comfort resulting from their inherent hydrophobicity, and do not possess antibacterial function which is vital for preventing bacterial infections. To address these issues, this study employed polylysine (PLL) biomolecule to fabricate the hydrophilic and antibacterial surface on PA fabric by a dip coating technique. The Schiff base reaction between the aldehyde groups of glutaraldehyde and the amino groups of PLL and PA fiber was utilized to increase washing resistance. The effects of the dip coating conditions of PLL on the hydrophilicity of PA fabric were studied by the wetting time of water droplet. The hydrophilicity imparted to PA fabric by PLL coating was further confirmed by water contact angle, moisture adsorption and capillary effect tests. The PLL coated fabric exhibited excellent hydrophilic and antibacterial properties with good washing durability. The functional surface of the PLL coated fabric was proved by scanning electron microscope, X-ray photoelectron spectroscopy, and charge effect. The present research suggests that PLL biomolecule can be used as a surface coating agent for simultaneously imparting hydrophilic and antibacterial functions to PA fiber.

In-Situ Surface Modification of Terpinen-4-ol Plasma Polymers for Increased Antibacterial Activity.

Surface modification of thin films is often performed to enhance their properties. In this work, in situ modification of Terpinen-4-ol (T4) plasma polymer is carried out via simultaneous surface functionalization and nanoparticle immobilization. Terpinen-4-ol plasma polymers surface were decorated with a layer of ZnO nanoparticles in an oxygen plasma environment immediately after polymer deposition. A combination of hydrophilic modification and ZnO nanoparticle functionalization of the T4 polymer surface led to an enhancement in antibacterial properties by factor of 3 (from 0.75 to 0.25 CFU.mm−2). In addition, ZnO nanoparticle-modified coatings demonstrated improved UV absorbing characteristics in the region of 300–400 nm by 60% relative to unmodified coatings. The ZnO modified coatings were transparent in the visible region of 400–700 nm. The finding points towards the potential use of ZnO nanoparticle-modified T4 plasma polymers as optically transparent UV absorbing coatings.

Constructing zwitterionic polymer brush layer to enhance gravity-driven membrane performance by governing biofilm formation

In this study, zwitterionic polymer brushes with controlled architecture were grafted on the surface of gravity-driven membrane (GDM) via surface-initiated reaction to impart antifouling property. A variety of membrane characterization techniques were conducted to demonstrate the successful functionalization of zwitterionic polymers on PVDF hollow fiber membrane. The membrane underwent 90 min of reaction time possessing strong hydrophilicity and high permeability was determined as the optimal modified membrane. Long-term GDM dynamic fouling experiments operated for 30 days using sewage wastewater as feed solution indicated zwitterionic polymer modified membrane exhibit excellent membrane fouling resistance thus enhanced stable flux. Confocal laser scanning microscopy (CLSM) imaging implied that zwitterionic polymer modification significantly inhibit the adsorption of extracellular polymeric substances (EPS) which dominates fouling propensity, resulting in the formation of a thin biofilm with high porosity under synthetic functions of foulants deposition and microbial activities. Interfacial free energy prediction affirmed the presence of zwitterionic functional layer on membrane surface could substantially decrease the interactions (e.g., electrostatic attractions and hydrophobic effects) between membrane and foulants, thereby reduced flux decline and high stable flux. Our study suggests surface hydrophilic functionalization shows promising potential for improving the performance of ultra-low pressure filtration.