Effect Of Hydrophilicity Research Articles

Influence of Substrate Hydrophilicity on Structural Properties of Supported Lipid Systems on Graphene, Graphene Oxides, and Silica.

Pristine graphene, a range of graphene oxides, and silica substrates were used to investigate the effect of surface hydrophilicity on supported lipid bilayers by means of all-atom molecular dynamics simulations. Supported 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid bilayers were found in close-contact conformations with hydrophilic substrates with as low as 5% oxidation level, while self-assembled monolayers occur on pure hydrophobic graphene only. Lipids and water at the surface undergo large redistribution to maintain the stability of the supported bilayers. Deposition of bicelles on increasingly hydrophilic substrates shows the continuous process of reshaping of the supported system and makes intermediate stages between self-assembled monolayers and supported bilayers. The bilayer thickness changes with hydrophilicity in a complex manner, while the number of water molecules per lipid in the hydration layer increases together with hydrophilicity.

Surface Wettability Tuning of Acrylic Resin Photoresist and Its Aging Performance.

Photoresist is the key material in the fabrication of micropatterns or microstructures. Tuning the surface wettability of photoresist film is a critical consideration in its application of microfluidics. In this work, the surface wettability tuning of acrylic resin photoresist by oxygen plasma or ultra-violet/ozone, and its aging performance in different atmospheres, were systematically studied. The chemical and physical characterizations of the surfaces before and after modification show a dramatic decrease in the C–C group and increase in surface roughness for oxygen plasma treatment, while a decrease of the C–C group was found for the UV/ozone treatment. The above difference in the surface tuning mechanism may explain the stronger hydrophilic modification effect of oxygen plasma. In addition, we found an obvious fading of the wettability tuning effect with an environment-related aging speed, which can also be featured by the decrease of the C–C group. This study demonstrates the dominated chemical and physical changes during surface wettability tuning and its aging process, and provides basis for surface tuning and the applications in microfluidics.

Hydrophilic and Hydrophobic Effects on the Structure and Themodynamic Properties of Confined Water: Water in Solutions

NMR spectroscopy is used in the temperature range 180–350 K to study the local order and transport properties of pure liquid water (bulk and confined) and its solutions with glycerol and methanol at different molar fractions. We focused our interest on the hydrophobic effects (HE), i.e., the competition between hydrophilic and hydrophobic interactions. Nowadays, compared to hydrophilicity, little is known about hydrophobicity. Therefore, the main purpose of this study is to gain new information about hydrophobicity. As the liquid water properties are dominated by polymorphism (two coexisting liquid phases of high and low density) due to hydrogen bond interactions (HB), creating (especially in the supercooled regime) the tetrahedral networking, we focused our interest to the HE of these structures. We measured the relaxation times ( and ) and the self-diffusion (D). From these times, we took advantage of the NMR property to follow the behaviors of each molecular component (the hydrophilic and hydrophobic groups) separately. In contrast, D is studied in terms of the Adam–Gibbs model by obtaining the configurational entropy (S) and the specific heat contributions (C). We find that, for the HE, all of the studied quantities behave differently. For water–glycerol, the HB interaction is dominant for all conditions; water–methanol, two different T-regions above and below 265 K are observable, dominated by hydrophobicity and hydrophilicity, respectively. Below this temperature, where the LDL phase and the HB network develops and grows, with the times and C change behaviors leading to maxima and minima. Above it, the HB becomes weak and less stable, the HDL dominates, and hydrophobicity determines the solution.

α-Cellulose-based films: effect of sodium lignosulfonate (SLS) incorporation on physicochemical and antibacterial performance

A homogeneous α-cellulose film was prepared by a regeneration method from ZnCl2/CaCl2/cellulose mixed system and was further combined with sodium lignosulfonate (SLS) via crosslinking through intermolecular hydrogen bonds and “bridge linkages”. The physicochemical and antibacterial performance of prepared films were investigated and results showed that the modified film exhibited stronger tensile strength, higher thermal stability, lower hydrophilic effect, better UV shielding as compared with the original one, and especially, better antibacterial ability derived from the presence of phenolic hydroxyl and sulfonate groups in SLS. This study proposed a simple and sustainable method for fabricating a multifunctional and environmentally friendly composite film using two main lignocellulose resources as raw materials.

The Development of an In Vitro Horizontal Diffusion Cell to Monitor Nasal Powder Penetration Inline.

The development of in vitro investigation models could be important using sensitive and fast methods during formulation. Intranasal applied drugs (meloxicam, lamotrigine, and levodopa) avoid the gastrointestinal tract and can achieve higher bioavailability, therefore a penetration extent is a key property. In this study, the in vitro adaptability of a modified horizontal diffusion cell was tested by using these model active pharmaceutical ingredients (APIs). The special factors consisted of the volume of the chambers, the arrangement of the stirrers, the design of probe input for real-time analysis and decreased membrane area. Membranes were impregnated by isopropyl myristate and by using phosphate buffer to evaluate the effect of API hydrophilicity on the diffusion properties. The lipophilicity of the API was proportional to the penetration extent through isopropyl myristate-impregnated membranes compared with buffer-soaked membranes. After evaluating the arithmetic mean of standard relative deviations and the penetrated extent of APIs at 15 min, Metricel® could be suggested for levodopa and meloxicam, and Whatman™ for lamotrigine. The modified model is suitable for inline, real-time detection, at nasal conditions, using small volumes of phases, impregnated membrane, to monitor the diffusion of the drug and to determine its concentration in the acceptor and donor phases.

Bowl-like mesoporous polydopamine with size exclusion for highly selective recognition of endogenous glycopeptides

It has been confirmed that endogenous glycopeptide plays an important role in a variety of pathological and physiological processes. However, direct analysis of endogenous glycopeptide is still a great challenge owing to the low abundance of endogenous glycopeptides and the presence of a large number of interfering substances such as large-sized proteins and heteropeptides in complex biological sample. Herein, we reported a novel bowl-like mesoporous polydopamine nanoparticle modified by carrageenan (denoted as MPDA@PEI@CA) with strong hydrophilicity and size-exclusion effect for high specificity enrichment of endogenous glycopeptides. Thanks to the suitable pore channel structure as well as strong hydrophilic surface, the as-prepared MPDA@PEI@CA nanoparticles exhibited prominent performance in enrichment of N-linked glycopeptide with ultrahigh selectivity (1:5000 M ratio of horseradish peroxidase (HRP) digests/bovine serum albumin (BSA) digests), low detection limit (5 fmol μL−1), outstanding size-exclusion ability (1:1000 mass of HRP/BSA), and unique reusability (five times). 125 N-glycosylation sites of 134 glycopeptides from 65 glycoproteins were identified from 2 μL sample of human serum treated with the MPDA@PEI@CA nanoparticles, which manifested the ability to enrich endogenous N-linked glycopeptides from complex biological samples. These results indicated that the bowl-like MPDA@PEI@CA nanoparticles with novel structure prepared in this work had great potential for glycopeptidome analysis.

Recent Advances of Triazine-Based Materials for Adsorbent Based Extraction Techniques.

This review mainly focused on the synthesis and properties of triazine-based materials as well as the state-of-the-art development of these materials in adsorption-based extraction techniques in the past 5 years, such as solid-phase extraction, magnetic solid-phase extraction, solid-phase microextraction and stir bar sorptive extraction, and the detection of various pollutants, including metal ions, drugs, estrogens, nitroaromatics, pesticides, phenols, polycyclic aromatic hydrocarbons and parabens. In the triazine-functionalized composites, triazine-based polymers and covalent triazine frameworks have been developed as the adsorbents with potential for environmental pollutants, mainly relying on the large surface area and the affinity of triazinyl groups with the targets. Triazine-based adsorbents have satisfactory sensitivity and selectivity towards different types of analytes, attributed from various mechanisms including π-π, electrostatics, hydrogen bonds, and hydrophobic and hydrophilic effects. The prospects of the materials for adsorption-based extraction were also presented, which can offer an outlook for the further development and applications.

Effect of Polymer Hydrophilicity and Molar Mass on the Properties of the Protein in Protein-Polymer Conjugates: The Case of PPEylated Myoglobin.

Polyphosphoesters (PPEs), a versatile class of biodegradable and biocompatible polymers, have been proposed as alternatives to poly(ethylene glycol) (PEG), which is suspected to be responsible for anaphylactic reactions in some patients after the administration of PEGylated compounds, e.g., in the current Covid-19 vaccines. We present the synthesis and characterization of a novel set of protein–polymer conjugates using the model protein myoglobin and a set of PPEs with different hydrophilicity and molar mass. We report an extensive evaluation of the (bio)physical properties of the protein within the conjugates, studying its conformation, residual activity, and thermal stability by complementary techniques (UV–vis spectroscopy, nano-differential scanning calorimetry, and fluorometry). The data underline the systematic influence of polymer hydrophilicity on protein properties. The more hydrophobic polymers destabilize the protein, the more hydrophilic PPEs protect against thermally induced aggregation and proteolytic degradation. This basic study aims at guiding the design of future PPEylated drugs and protein conjugates.

Impact of Surface Hydrophilicity on Electrochemical Water Splitting.

The activity of electrocatalysts can be improved by modifying their electronic structures and surface morphologies. In electrochemical reactions with gas evolution, the performance of an electrocatalyst is also affected by how easily gas bubbles depart from an electrocatalyst surface. However, it is difficult to quantitatively estimate the improvement in the performance that can be achieved by promoting the departure of gas bubbles from the electrocatalyst surface. This study investigated the effect of surface hydrophilicity on the hydrogen evolution reaction (HER). The water contact angles of the nickel phosphorous (NiP) films were controlled from 40.3 to 77.2° with imperceptible differences in their intrinsic electronic structures and surface areas. Electrochemical analyses and in situ visualization of the gas evolution on the NiP films indicated that an increase in the hydrophilicity of the electrocatalysts reduced the size of gas bubbles formed on the NiP films and shortened the duration of the bubbles' stay on the NiP surface. A faster gas departure enabled continuous participation of the electrocatalyst surface in hydrogen evolution, leading to a stable electrochemical behavior of the electrocatalyst and a decrease in the overpotential at a given current density. A full-cell test revealed that the enhancement of hydrogen bubble departure on a hydrophilic NiP surface with a contact angle of 40.3° reduced the overpotential by 134 mV at a current density of 100 mA/cm2 compared to a more hydrophobic film with a contact angle of 77.2°.

Investigating the effect of water‐mixing nitrogen atmospheric pressure plasma jet on polyether‐ether‐ketone and time stability under different conditions

AbstractPossessing excellent properties including good biocompatibility, high strength, and stiffness, polyether‐ether‐ketone (PEEK) has significant application values in medical and industrial fields. However, the relatively poor wettability and low adhesion limit its further applications. Atmospheric pressure plasma jet (APPJ) has been utilized for adjusting PEEK properties, but better hydrophilization effect and time stability after treatment are still urgently needed. In this paper, we employ a water‐mixing nitrogen (N2H2O) APPJ to process PEEK, and surface wettability can be effectively improved (contact angle ~18° within 2 min, distance between sample and nozzle outlet: 10 mm) without inducing obvious microstructure damages. Additionally, after storing for 40 days, the sample treated by N2H2O APPJ also possessed better wettability (~54°) compared with that treated by N2 APPJ (~65°). On the basis of this low‐damage and high‐efficient modification method, we perform aging experiments under different conditions (different temperatures 25, −10°C; and low vacuum condition: 50 kPa) to determine a relatively optimum storing condition for this method. The experiment results indicate that low temperature and vacuum are conducive to retaining the plasma‐induced wettability (~34°). The treatment method and storing conditions for PEEK presented here may facilitate the application of PEEK in various fields.

Biomimetic biohybrid nanofibers containing bovine serum albumin as a bioactive moiety for wound dressing

For the first time, a biohybrid nanofibrous wound dressing is developed via green electrospinning of a blend solution of bovine serum albumin (BSA) (1 and 3 wt%) and polycaprolactone (PCL). In such a system, the components are miscible and interact through hydrogen bonding between the carbonyl group of PCL and the amine group of BSA, as verified by ATR-FTIR. As a result, the biohybrid nanofibers show a superior elastic modulus and elongation (300% and 58%, respectively) compared with the neat PCL nanofibers. The included protein induces a hydrophilicity effect to the PCL nanofibers, notably at the higher BSA content (3 wt%). In contrast to the neat nanofibers, the biohybrid ones are bioactive and encourage formation of biominerals (made of amorphous calcium carbonate) on the surface, after immersion in simulated body fluid (SBF). Based on the WST-8 cell viability tests, NIH3T3 fibroblast cells were seen to properly interact with the biohybrid mats and to proliferate in their proximity. SEM images show that the cells largely adhere onto such nanofibers even more than they do on the neat ones and adopt a flattened and stretched shape. In addition, the live/dead assay and phalloidin/DAPI staining assay confirm large cell viability and normal cell morphology on the biohybrid nanofiber mats after 4 days incubation. Taken together, BSA/PCL nanofibers are able to offer optimum mechanical properties (elasticity) as well as mineralization which can potentially stimulate the wound healing process, and can be considered a suitable candidate for wound dressing applications.

Molecular understanding of the LCST phase behaviour of P(MEO2MA-b-OEGMA) block copolymers

ABSTRACT The lower critical solution temperature (LCST) behaviour of block copolymer 2-(2-methoxyethoxy) ethyl methacrylate and oligo (ethylene glycol) methacrylate (P(MEO2MA-b-OEGMA)) was studied by molecular dynamics simulations. Our simulations show that the LCST of P(MEO2MA-b-OEGMA) is linear to its OEGMA block ratio, which is agreed with our previous experimental observations. Meanwhile, the mechanism of the LCST phase behaviour was also revealed by our simulations. The hydrophilic effect of copolymer and the entropy effect of water are the main factors of affecting the aggregate behaviours of copolymers and further affect their LCSTs. The hydrophilic effect is dominant and these water molecules are apt to gather around the copolymers and the copolymers exist in a coil state when the temperature is relatively lower. However, the entropy effect of water prevails and the copolymers tend to in a globule state when the temperature is higher. The coil-to-globule transition occurs when the temperature reaches a certain degree, namely LCST, at which the competition between the hydrophilic effect of copolymer and entropy effect of water reaches a balance.

Role and application of glycosaminoglycans in trichology and cosmetology

Glycosaminoglycans are structurally complex, linear polysaccharides. They show a hydrophilic effect and have the ability to bind water. In cosmetic preparations, they are obtained biotechnologically and appear in the form of hyaluronic acid, sodium hyaluronate and potassium hyaluronate. The aim of the study was to present the possibility of using glycosamidoglycans in cosmetology, trichology and aesthetic dermatology. These compounds are considered safe for topical application, they keep the skin in proper condition, support cell renewal, and increase the skin’s resistance to harmful external factors. They also bring satisfactory results in terms of application in trichology. A number of studies show that they stimulate hair growth, reduce excessive flaking of the scalp, seborrhea and support the treatment of androgenetic alopecia.

In vitro and in vivo evaluation of a nanofiber wound dressing loaded with melatonin

Wound healing is a complicated process that takes a long time to complete. The three-layer nanofiber wound dressing containing melatonin is highly expected to show remarkable wound repair by reducing the wound healing time. In this study, chitosan (Cs)-polycaprolactone (PCL)/ polyvinylalcohol (PVA)-melatonin (MEL)/ chitosan-polycaprolactone three-layer nanofiber wound dressing was prepared by electrospinning for melatonin sustained release. The characteristics of the wound dressing were further evaluated. The wound dressing had a high water uptake after 24 h (401%), and the water contact angle results showed that it had hydrophilicity effect that supported the cell attachment. The wound healing effect of wound dressing was examined using a full-thickness excisional model of rat skin by the local administration of MEL. The gene expressions of transforming growth factor-beta (TGF-β1), alpha-smooth muscle actin (α-SMA), collagen type I (COL1A1), and collagen type III (COL3A1) were further studied. The histopathological evaluation showed the complete regeneration of the epithelial layer, remodeling of wounds, collagen synthesis, and reduction in inflammatory cells. The NF + 20% MEL significantly increased TGF-β1, COL1A1, COL3A1, and α-SMA mRNA expressions. This wound dressing may have a considerable potential as a wound dressing to accelerate the wound healing.

Super-hydrophilic TiO2-based coating of anion exchange membranes with improved antifouling performance

The fabrication of reliable anion exchange membranes (AEMs) with superior antifouling abilities is critical in applications of electrodialysis (ED) technology. Surface modification with hydrophilic nanoparticles to improve antifouling of the membrane is an effective method. In this study, the effect of hydrophilicity of the AEMs surface on their antifouling properties was studied in detail. Commercial AEMs were modified with super-hydrophilic titanium dioxide (TiO2) coating assisted by polydopamine (PDA) and poly (sodium 4-styrene sulfonate) (PSS). Owing to the strong adhesion of PDA, a stable TiO2 layer was constructed on the membrane surfaces and endowed them super-hydrophilic properties. These modified AEMs exhibited slightly increased membrane area resistance compared to the pristine membrane, while after 100-min fouling experiments with sodium dodecyl benzene sulfonate (SDBS) the resistance of the 0.75 g/L-DA modified membrane increased only marginally relative to 48 % of the pristine membrane. The feasibility of rapid cleaning during ED separation operated with SDBS as the foulant without ultraviolet (UV) irradiation was also investigated. Ascribed to the super-hydrophilicity of the TiO2 modified surface, the modified AEMs showed good fouling reversibility through simply water rinsing.

Effects of functional groups of –NH2 and –NO2 on water adsorption ability of Zr-based MOFs (UiO-66)

Abstract The high surface areas and tunable properties of Zr-based MOFs make them as attractive materials for gas capture, storage, and separation. In this work, UiO-66, one kinds of Zr-based MOFs, functionalized by single or binary –NO2 and –NH2 groups are synthesized. Water adsorption ability and hydrophilicity of UiO-66 and functionalized UiO-66-X were investigated. It is found that surface area of UiO-66 is decreased after introducing functional groups, while hydrophilicity of UiO-66 increased after functionalized with –NO2 and –NH2. Therefore, after balance the effects of surface area and hydrophilicity, UiO-66-NH2 shows the best water adsorption propriety.

浸漬型膜分離活性汚泥法の膜ファウリングに及ぼすpolytetrafluoroethylene平膜の親水性の影響

浸漬型膜分離活性汚泥法の膜ファウリングに及ぼすpolytetrafluoroethylene平膜の親水性の影響

Open-air synthesis of oligo(ethylene glycol)-functionalized polypeptides from non-purified N-carboxyanhydrides.

With PEG-like properties, such as hydrophilicity and stealth effect against protein absorption, oligo(ethylene glycol) (OEG)-functionalized polypeptides have emerged as a new class of biomaterials alternative to PEG with polypeptide-like properties. Synthesis of this class of materials, however, has been demonstrated very challenging, as the synthesis and purification of OEG-functionalized N-carboxyanhydrides (OEG-NCAs) in high purity, which is critical for the success in polymerization, is tedious and often results in low yield. OEG-functionalized polypeptides are therefore only accessible to a few limited labs with expertise in this specialized NCA chemistry and materials. Here, we report the controlled synthesis of OEG-functionalized polypeptides in high yield directly from the OEG-functionalized amino acids via easy and reproducible polymerization of non-purified OEG-NCAs. The prepared amphiphilic block copolypeptides can self-assemble into narrowly dispersed nanoparticles in water, which show properties suitable for drug delivery applications.

Glutaraldehyde cross-linked CDA/HBP-NH2 nanofiber membrane for adsorption of heavy metal ions in wastewater.

A new type of nanofiber membrane was prepared by mixed electrospinning of cellulose diacetate and amino-terminated hyperbranched polymer (HBP-NH2), and glutaraldehyde (GA) crosslinking was used to improve its water resistance and shape retention. pH, adsorption time, and initial solution concentration on Cu(ii) and Cr(vi) ions were studied. Results showed that the prepared GA-CDA/HBP-NH2 nanofiber had good spinning uniformity, hydrophilicity, and adsorption effect on Cu(ii) and Cr(vi) ions compared with the pure CDA nanofiber. The maximum adsorption capacity of GA-CDA/HBP-NH2 for Cu(ii) and Cr(vi) was 50.2 and 176.6 mg g−1, respectively.

Biodegradable Composite Nanofiber Containing Fish-Scale Extracts.

A biodegradable composite nanofiber containing polyhydroxyalkanoate (PHA) or modified PHA (MPHA) and treated fish-scale powder (TFSP) was prepared and characterized. The powder (20-80 nm) was prepared by grinding after treating FSP with water, acid, and heat (450 °C) to yield the TFSP. Composite nanofibers (100-500 nm long) of TFSP/PHA and TFSP/MPHA were fabricated by electrospinning using a biaxial feed method. The TFSP, which had a high hydroxyapatite content, was suitable as a filler for composites. The Ca/P ratio of the TFSP was similar to that of the human bone. Particle size analysis and analysis of scanning electron microscopy images indicated that, compared with the PHA/TFSP composite, the MPHA/TFSP nanofibers were more uniform and bonded more strongly in the matrix. The tensile strength at failure of the MPHA/TFSP specimens was enhanced and increased with increasing TFSP content. The elongation at failure was lower and decreased with increasing TFSP concentration. The water contact angle decreased with increasing TFSP content in PHA/TFSP and MPHA/TFSP nanofiber membranes. The TFSP enhanced the hydrophilic effect of the PHA/TFSP and MPHA/TFSP nanofiber membranes and provided a more suitable environment for cell growth. This composite nanofiber has potential in many biomedical applications.