Amphiphilic Modification Research Articles

Amphiphilic Post‐Modification of Red Algae‐Derived Carrageenan Coatings for Balanced Marine Antifouling Applications

AbstractPolysaccharide coatings are of interest for marine antifouling applications because of their good marine antifouling properties and environmentally benign characteristics. However, the hydrophilic nature of polysaccharide coatings can lead to the adsorption of marine sediment, which can negatively impact their antifouling properties. Amphiphilic modification of polysaccharide coatings has been demonstrated to address these issues. In this study, we report a simple method for post‐modification of a sulfated polysaccharide carrageenan (CAR) coating to make it amphiphilic. A hydrophilic CAR coating is first formed on solid substrates, followed by grafting hydrophobic molecules onto the CAR‐coated surfaces through metal‐ion‐mediated coordinate bond formation. The resulting amphiphilic CAR coating effectively reduces both marine sediment (silt) adsorption and marine diatom adhesion, achieving a balanced marine antifouling performance.

Incorporating amphiphilic modifier into PVDF membrane through in-situ electrostatic crosslinking for efficient oil-water separation

Constructing stable amphiphilic membrane surfaces in a facile and controlled way is highly desired for fabrication of antifouling water purification membranes. Herein, inspired by adhesives of sandcastle worms, we proposed an in-situ electrostatic crosslinking method to incorporate amphiphilic modifiers into poly (vinylidene fluoride) membranes. Pluronic F127 grafted with positively charged quaternary ammonium groups are added into the casting solution, while perfluorosulfonic acid bearing negatively charged sulfonic acid groups and perfluorocarbon chains are dissolved in the coagulation bath. During non-solvent induced phase separation process, electrostatic crosslinking between quaternary ammonium and sulfonic acid led to the in-situ formation of amphiphilic modifiers on membrane surfaces and pore walls. The resulting membrane exhibits high water permeance up to 625 Lm−2h−1 bar−1 and superior antifouling performance with total flux decline ratio of 2 % and flux recovery ratio of 99.3 % for oil-water separation. Besides, the membrane displays excellent structural stability and self-cleaning properties against highly viscous crude oils.

High-performance arabinoglucuronoxylan-based biosurfactants for oily sludge separation

Arabinoglucuronoxylan (AGX), an important carbohydrate polymer in lignocellulosic biomass, contains many functional groups. It has excellent amphiphilic modification properties and has potential application in the separation of oily sludge. In this study, a simple strategy for producing high-performance AGX-based biosurfactants was studied and the raw AGX was extracted from bamboo by hydrothermal treatment. AGX-based biosurfactants with amphiphilic structure were produced by AGX and dodecanal succinic anhydride (DDSA) using rapid homogeneous esterification reactions in deep eutectic solvents (DES). This resulted in a significant reduction in the surface tension of the water from 72.32 to 29.76 mN·m−1. These parameters are similar to those achieved using sodium dodecyl sulfate (SDS), a widely employed synthetic surfactant. Other physicochemical properties, including foamability, emulsification activity, stability, solubilization, and detergency were significantly improved compared to the unmodified AGX, demonstrate that AGX-based biosurfactants are promising detergents for oily sludge remediation and oil recovery. The results provide a new pathway for high value utilization of arabinoglucuronoxylan.

Removal effect and mechanism of amphiphilic chitosan modified microbubbles on microcystis aeruginosa

Algal blooms in lake and reservoir water lead to water quality problems, including water odors, algal toxins, and disinfection byproducts. A novel dissolved air flotation process that incorporates positively charged bubbles (PosiDAF) can effectively remove algae in lakes and reservoirs. Chitosan, as a modified bubble agent in the PosiDAF process, has attracted extensive attention due to its natural nontoxicity and good flocculation properties. In this paper, three types of amphiphilic chitosan with different lengths of carbon chains were prepared via amphiphilic modification and were used as bubble modifiers to remove microcystis aeruginosa in the PosiDAF process. The effects of algae removal under different dosage of modifiers were compared, and the role of algal organic matter was investigated. Results showed that the water solubility of chitosan was markedly enhanced after amphiphilic modification, while thermal stability were decreased. When using butyl-N-2 hydroxypropyl trimethyl chitosan ammonium chloride (C4-HTCC), the effect of modified air flotation was the best, and the removal ratio of algae was 93.47% when the C4-HTCC dosage was 1.0 mg/L. The presence of AOM enhanced the overall effect of algae removal, and electrostatic attraction was the primary adhesion mechanism of the microbubble-amphiphilic chitosan-algal organic matter-algal cell system. In addition, adsorption bridging and net trapping also have positive effects on algae removal.

Enhancing Antigen Presentation and Inducing Antigen-Specific Immune Tolerance with Amphiphilic Peptides.

Ag-specific immunotherapy to restore immune tolerance to self-antigens, without global immune suppression, is a long-standing goal in the treatment of autoimmune disorders such as type 1 diabetes (T1D). However, vaccination with autoantigens such as insulin or glutamic acid decarboxylase have largely failed in human T1D trials. Induction and maintenance of peripheral tolerance by vaccination requires efficient autoantigen presentation by APCs. In this study, we show that a lipophilic modification at the N-terminal end of CD4+ epitopes (lipo-peptides) dramatically improves peptide Ag presentation. We designed amphiphilic lipo-peptides to efficiently target APCs in the lymph nodes by binding and trafficking with endogenous albumin. Additionally, we show that lipophilic modification anchors the peptide into the membranes of APCs, enabling a bivalent cell-surface Ag presentation. The s.c. injected lipo-peptide accumulates in the APCs in the lymph node, enhances the potency and duration of peptide Ag presentation by APCs, and induces Ag-specific immune tolerance that controls both T cell- and B cell-mediated immunity. Immunization with an amphiphilic insulin B chain 9-23 peptide, an immunodominant CD4+ T cell epitope in NOD mice, significantly suppresses the activation of T cells, increases inhibitory cytokine production, induces regulatory T cells, and delays the onset and lowers the incidence of T1D. Importantly, treatment with a lipophilic β-cell peptide mixture delays progression to end-stage diabetes in acutely diabetic NOD mice, whereas the same doses of standard soluble peptides were not effective. Amphiphilic modification effectively enhances Ag presentation for peptide-based immune regulation of autoimmune diseases.

Amphiphilic core–shell magnetic adsorbents for efficient removal and detection of phthalate esters

A new class of amphiphilic magnetic adsorbents (denoted as Fe3O4-GPS-A) is fabricated by functionalization of the Fe3O4 surface with six different amphiphilic silanizing agents that are specifically tailor-made to the chemical structure of PAEs. The resulting Fe3O4-GPS-A exhibit different contact angles due to the significant changes in functional groups, as revealed by 1H NMR and FTIR spectroscopy. Among six Fe3O4-GPS-A, Fe3O4-DOA and Fe3O4-OAN exhibit a fast adsorption process (within 60 min) and high adsorption capacity for dibutyl phthalate (DBP) and dioctyl phthalate (DOP), two commonly used phthalate esters (173.7 mg g−1 for DOP and 104.4 mg g−1 for DBP), in conjunction with fast magnetic responsiveness and good thermal stability. The adsorption performance of Fe3O4-DOA and Fe3O4-OAN were well-maintained even after ten cycles. Besides, the adsorption mechanism was investigated through adsorption fitting models and theoretical calculations, which inferred that the interactions between adsorbent and adsorbate are mainly based on hydrophobic interactions along with secondary non-covalent contacts. Finally, the adsorbents combined with GC–MS analyses were applied to monitor DBP and DOP in the lake water samples. This work not only opens up a strategy for amphiphilic modification of magnetic adsorbents, but also provides a new avenue in their application for phthalate esters detection.

Toward a Two-Dimensional Supramolecular Organic Framework with High Degree of Internal Order via Amphiphilic Modification

Solution-phase self-assembly of two-dimensional (2D) networks with a high degree of internal order and long-range periodicity is a great challenge. Herein, we report a rational design to improve 2D...

Synergistic Effect of Fluorinated Passivator and Hole Transport Dopant Enables Stable Perovskite Solar Cells with an Efficiency Near 24%

Long-term durability is critically important for the commercialization of perovskite solar cells (PSCs). The ionic character of the perovskite and the hydrophilicity of commonly used additives for the hole-transporting layer (HTL), such as lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) and tert-butylpyridine (tBP), render PSCs prone to moisture attack, compromising their long-term stability. Here we introduce a trifluoromethylation strategy to overcome this drawback and to boost the PSC's solar to electric power conversion efficiency (PCE). We employ 4-(trifluoromethyl)benzylammonium iodide (TFMBAI) as an amphiphilic modifier for interfacial defect mitigation and 4-(trifluoromethyl)pyridine (TFP) as an additive to enhance the HTL's hydrophobicity. Surface treatment of the triple-cation perovskite with TFMBAI largely suppressed the nonradiative charge carrier recombination, boosting the PCE from 20.9% to 23.9% and suppressing hysteresis, while adding TFP to the HTL enhanced the PCS's resistance to moisture while maintaining its high PCE. Taking advantage of the synergistic effects resulting from the combination of both fluoromethylated modifiers, we realize TFMBAI/TFP-based highly efficient PSCs with excellent operational stability and resistance to moisture, retaining over 96% of their initial efficiency after 500 h maximum power point tracking (MPPT) under simulated 1 sun irradiation and 97% of their initial efficiency after 1100 h of exposure under ambient conditions to a relative humidity of 60-70%.

In situ amphiphilic modification of thin film composite membrane for application in aqueous and organic solvents

Conventional support (uncrosslinked) based polyamide (PA) thin film composite (TFC) membranes are indispensable for desalination and purification of water. In addition to water purification, an emerging application of TFC membrane is the nanofiltration of organic solvents if the support layer is solvent resistant. However, solvent resistant PA TFC membranes show good permeate flux of polar solvents but low flux of non-polar solvents. We report that amphiphilic PA barrier layer is required to obtain good permeate flux of polar and nonpolar solvents. Herein, a facile approach for the in situ amphiphilic modification of PA layer of TFC membrane for application in aqueous and organic (polar and non-polar) medium is reported. Amphiphilic PA layers have been fabricated on conventional polysulfone (PSf) and solvent resistant polyimide (PI) supports. Interfacial polymerization (IP) between mixture of m-phenylenediamine (MPD) and MPD-capped polyethylene glycol (MPD-PEG-MPD) and mixture of trimesoyl chloride (TMC) and TMC-capped polydimethylsiloxane (TMC-PDMS-TMC) produces amphiphilic TFC membranes. Hydrophobic TFC membranes have been prepared by the IP between MPD and mixture of TMC and TMC-PDMS-TMC. The TFC membranes exhibit tunable water wetting behavior (water contact angle = 61-110o) depending on the composition of the organic phase. Amphiphilic TFC membranes show surface rearrangement/reconstruction behavior in contact with water and non-polar solvent. The amphiphilic membranes show good antifouling property with reduction of flux to about 14% and recovery in the flux to about 97% during desalination of water containing bovine serum albumin. The hydrophobic and amphiphilic TFC membranes (solvent resistant) showed significant improvement in the permeate flux of toluene and hexane. Particularly, amphiphilic solvent resistant membranes are suitable for application in water and nanofiltration of polar and non-polar solvents.

Nanocomposite of Graphene Oxide Encapsulated in Polymethylmethacrylate (PMMA): Pre-Modification, Synthesis, and Latex Stability

The compatibility of graphene oxide with its dispersion medium (polymer) plays a critical role in the formation of nanocomposite materials with significant property improvements. Environmentally friendly miniemulsion polymerization, which allows a formation of nanoencapsulation in an aqueous phase and high molecular weight polymer/composite production is one promising method. In this study, we screened a series of amphiphilic modifiers and found that the quaternary ammonium (ar-vinyl benzyl) trimethyl ammonium chloride (VBTAC) pending carbon double bonds could effectively modify the graphene oxide (GO) to be compatible with the organophilic monomer. After that, free radical miniemulsion polymerization successfully synthesized stable latex of exfoliated poly (methyl methacrylate) (PMMA)/ GO nanocomposite. The final latex had an extended storage life and a relatively uniform particle size distribution. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) analysis of this latex and its films indicated successful encapsulation of exfoliated nano-dimensional graphene oxide inside a polymer matrix.

Preparation and Characterization of Monodisperse Mesoporous SiO<sub>2</sub> Microspheres Modified by Octaphenylpolyoxyethyiene

Monodisperse mesoporous SiO2 microsphere is a potential fine candidate carrier of dry powder inhalation, but large numbers of active surface hydrophilic hydroxyls enhance surface energy, hydrogen bonding and electrostatic force, environmental water adsorption and particle agglomeration. Conventional hydrophobic modification of surface hydroxyls, which is conducive to solve the above-mentioned disadvantages, will limit the loading of water-soluble drugs and the drug dissolution in water simultaneously. In this study, monodisperse mesoporous SiO2 microspheres were prepared as carrier and modified innovatively by amphiphilic modifier octaphenylpolyoxyethyiene and 3-aminopropyltriethoxysilane, particle diameter about 60 nm, mean pore size 21.4 nm, specific pore volume 0.95 cm3/g, and specific surface area 130 m2/g. Model drug pentoxyverine citrate was loaded by pressure infiltration and spray drying process, drug loading 8.24%, repose angle 34°, mass median aerodynamic diameter 1.03 μm, and more than 90% of drug could dissolve within 30 min both in water and organic solvents.

Recent Advances in the Design of Self‐Delivery Amphiphilic Drugs and Vaccines

AbstractAmphiphilic drugs are molecular drugs or drug conjugates possessing both hydrophilic and lipophilic properties. Representative amphiphilic drugs are composed of a pharmaceutical payload, a linker, and an appropriate amphiphilic modification. The physicochemical properties of amphiphilic drugs can be tailored by structure‐based engineering, which ultimately determine the drug molecules’ self‐assemble ability, bioavailability, protein binding, membrane anchoring, organ and intracellular distributions, side effects, and biological efficacy. Unlike the traditional carrier‐assistant drug delivery system, many of the amphiphilic drugs are carrier‐free and can self‐deliver to target sites/cells and access intracellular organelles without an external delivery carrier. This is achieved by molecular designs that control the delivery pathways of amphiphilic drugs at organ/tissue, cellular, and intracellular levels. In this review the recent advances in self‐delivery amphiphilic drugs and vaccines are highlighted, with emphasis on the underlying design principles and emerging applications.

Hydrogen production from bio-derived biphasic photoreforming over a raspberry-like amphiphilic Ag2O-TiO2/SiO2 catalyst

Photoreforming of bio-derived liquids is anattractive approach toward sustainable H2 production. Although a large number of bio-liquids are thermodynamically feasible for photocatalytic hydrogen production, few of them have been involved in this process due to their water insoluble nature. To achieve and promote the efficiency of photoreforming hydrogen production in bio-derived biphasic system, the Pickering interfacial catalysis was established over an amphiphilic Ag2O-TiO2/SiO2 catalyst. In this case, the Ag2O-TiO2/SiO2 sample was synthesized by means of an electrostatic self-assembly method by surface charge regulation of SiO2 and the surface hydrophobic modification of Ag2O-TiO2/SiO2 particles using a Pickering emulsion method. As shown in the results, the amphiphilic Ag2O-TiO2/SiO2 particles were observed to successfully stabilize the bio-octanol/water emulsion. Even the complex structure and surface modification slightly reduce the light absorption efficiency and specific surface area of the catalyst, the hydrogen yield was greatly promoted over Ag2O-TiO2/SiO2 compared to that of bare TiO2, Ag2O-TiO2 and TiO2/SiO2. It was also discovered that the cyclic hydrogen production performance can be improved by simple re-emulsification. The effect of bio-octanol concentration for photoreforming was studied by a Langmuir-Hinshelwood-type kinetic model, and the reaction rate constant and bio-octanol adsorption constant were obtained. This study shows that photocatalyst after effective surface amphiphilic modification could provide a prospective approach for the hydrogen production from a bio-derived oil/water biphasic system under solar light.

Hydrophilic and anti-fouling PVDF blend ultrafiltration membranes using polyacryloylmorpholine-based triblock copolymers as amphiphilic modifiers

To fabricate hydrophilic and anti-fouling PVDF ultrafiltration membrane, a kind of tailor-made symmetrical amphiphilic triblock copolymer, polyacryloylmorpholine-b-poly (methyl methacrylate)-b-polyacryloylmorpholine (PACMO-b-PMMA-b-PACMO, termed as PAMA), was prepared via RAFT polymerization and employed as an in situ surface segregation modifier. FTIR, 1H NMR, and GPC were used to verify the well-defined chemical structure of PAMA. The hydrophilic PACMO segments of PAMA were enriched on the surface of membrane skin and interior pores as confirmed by ATR-FTIR, XPS, EDX, and water contact angle tests, endowing the blend membranes with outstanding hydrophilicity. The different cross-sectional and surface morphologies of the PVDF/PAMA blend membranes indicated that the introduction of PAMA modifiers could manipulate membrane structure due to their strong pore-forming ability. Compared with the pure PVDF membrane, PVDF/PAMA blend membranes showed higher permeability for water (28.1 times higher), excellent rejection for bovine serum albumin (up to 98.3%), and enhanced fouling resistance with a higher flux recovery ratio (up to 98.1%). Therefore, the approach of in situ surface segregation employed the RAFT mediated well-defined amphiphilic PAMA triblock copolymer modifiers for the preparation of anti-fouling PVDF membranes showed a great potential in water purification.

Long-Circulating Amphiphilic Doxorubicin for Tumor Mitochondria-Specific Targeting

The mitochondria have emerged as a novel target for cancer chemotherapy primarily due to their central roles in energy metabolism and apoptosis regulation. Here, we report a new molecular approach to achieve high levels of tumor- and mitochondria-selective deliveries of the anticancer drug doxorubicin. This is achieved by molecular engineering, which functionalizes doxorubicin with a hydrophobic lipid tail conjugated by a solubility-promoting poly(ethylene glycol) polymer (amphiphilic doxorubicin or amph-DOX). In vivo, the amphiphile conjugated to doxorubicin exhibits a dual function: (i) it binds avidly to serum albumin and hijacks albumin's circulating and transporting pathways, resulting in prolonged circulation in blood, increased accumulation in tumor, and reduced exposure to the heart; (ii) it also redirects doxorubicin to mitochondria by altering the drug molecule's intracellular sorting and transportation routes. Efficient mitochondrial targeting with amph-DOX causes a significant increase of reactive oxygen species levels in tumor cells, resulting in markedly improved antitumor efficacy than the unmodified doxorubicin. Amphiphilic modification provides a simple strategy to simultaneously increase the efficacy and safety of doxorubicin in cancer chemotherapy.

A directional entrapment modification on the polyethylene surface by the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether

A novel entrapment modification method involving directional implantation of the amphiphilic modifier of stearyl-alcohol poly(ethylene oxide) ether (AEO) into the high-density polyethylene (HDPE) surface is proposed. This modification technique allows the AEO modifier to be able to spontaneously attain and subsequently penetrate into the swollen HDPE surface with its hydrophobic stearyl segment, while its hydrophilic poly(ethylene oxide) (PEO) segment spontaneously points to water. The AEO modifier with a HLB number below 8.7 was proved appropriate for the directional entrapment, Nevertheless, AEOs with larger HLB numbers were also effective modifiers in the presence of salt additives. In addition, a larger and hydrophobic micelle, induced respectively by the AEO concentration above 1.3 × 10−2 mol/L and the entrapping temperature above the cloud point of AEO, could lead to a sharp contact angle decline of the modified surface. Finally, a hydrophilic HDPE surface with the modifier coverage of 38.9% was reached by the directional entrapment method, which is far larger than that of 19.2% by the traditional entrapment method.

Immunostimulatory Properties of Lipid Modified CpG Oligonucleotides

Innate immune responses recognizing pathogen associated molecular patterns play important roles in adaptive immunity. As such, ligands which mimic the conserved products of microbial and activate innate immunity are widely used as adjuvants for vaccines. Synthetic single strand oligodeoxynucleotides (ODNs) containing unmethylated cytosine-guanine (CpG) motifs which bind Toll-like receptor 9 (TLR9) are powerful molecular adjuvants, potentiating both humoral and cellular responses. However, CpG ODN's in vitro potency has not been translated to in vivo settings primarily due to issues associated with delivery and toxicity. A major challenge in clinical application of CpG ODN is the efficient delivery to lymph nodes, the anatomic sites where all the immune responses are initiated. Targeting CpG to the key antigen presenting cells (APC) is essential for its application as a vaccine adjuvant, as it not only enhances CpG's efficacy, but also greatly reduces the systemic toxicity. We recently discovered an "albumin-hitchhiking" approach by which CpG ODNs were conjugated to a lipophilic lipid tail and follow subcutaneous injection, accumulated in lymph nodes by binding and transporting with endogenous albumin. This molecular approach targets CpG to antigen presenting cells in the draining lymph nodes via an endogenous albumin-mediated mechanism and simultaneously improves both the efficacy and safety of CpG as a vaccine adjuvant. Since CpG ODNs can be divided into structurally distinct classes, and each class of CpG ODN activates different types of immune cells and triggers different types of immunostimulatory activities, it is important to thoroughly evaluate the efficacy of this "albumin-hitchhiking" strategy in each class of CpG. Here we compare the immunostimulatory activities of three classes of lipid conjugated CpG ODNs in vitro and in vivo. Three representative sequences of lipid modified CpG ODNs were synthesized and their stimulatory effects as a vaccine adjuvant were evaluated. Our results showed that in vitro, lipid modified class A CpG exhibited enhanced stimulatory activities toward TLR transfected reporter cells or bone-marrow derived dendritic cells, whereas lipid-modification of class B or C CpG reduces the activation of TLR9 by 2-3 fold, as compared with unmodified class B and class C CpG, respectively. However, in vivo coadministration of ovalbumin (OVA) protein antigen mixed with lipid-conjugated class B or C CpG ODNs, but not class A CpGs induced dramatically increased OVA-specific humoral and cytotoxic CD8+ T cells responses compared with OVA mixed with unmodified CpGs. Further, lipid-modification greatly reduces the toxicity associated with CpG by minimizing the systemic dissemination. Taken together, these results demonstrated that amphiphilic modification of three classes of CpG motifs differentially affected and modulated the immunostimulatory activities in vitro and in vivo. Our study highlights the importance of in vivo lymph node targeting of CpG ODNs in fulfilling their use as vaccine adjuvants, providing implications for the rational design of molecular adjuvant for subunit vaccines.

Tailoring the supramolecular structure of amphiphilic glycopolypeptide analogue toward liver targeted drug delivery systems

Amphiphilic glycopolypeptide analogues have harboured great importance in the development of targeted drug delivery systems. In this study, lactosylated pullulan-graft-arginine dendrons (LP-g-G3P) was synthesized using Huisgen azide-alkyne 1,3-dipolar cycloaddition between lactosylated pullulan and generation 3 arginine dendrons bearing Pbf and Boc groups on the periphery. Hydrophilic lactosylated pullulan was selected for amphiphilic modification, aiming at specific lectin recognition. Macromolecular structure of LP-g-G3P combined alkyl, aromatic, and peptide dendritic hydrophobic moieties and was able to self-assemble spontaneously into core-shell nanoarchitectures with small particle sizes and low polydispersity in the aqueous media, which was confirmed by CAC, DLS and TEM. Furthermore, the polyaromatic anticancer drug (doxorubicin, DOX) was selectively encapsulated in the hydrophobic core through multiple interactions with the dendrons, including π-π interactions, hydrogen bonding and hydrophobic interactions. Such multiple interactions had the merits of enhanced drug loading capacity (16.89±2.41%), good stability against dilution, and excellent sustained release property. The cell viability assay presented that LP-g-G3P nanoparticles had an excellent biocompatibility both in the normal and tumor cells. Moreover, LP-g-G3P/DOX nanoparticles could be effectively internalized into the hepatoma carcinoma cells and dramatically inhibited cell proliferation. Thus, this approach paves the way to develop amphiphilic and biofunctional glycopolypeptide-based drug delivery systems.

Novel ‘Pickering’ modified TiO2 photocatalysts with high De-NOx efficiency

Modified TiO2 nanoparticles were prepared by a Pickering emulsions route with the use of hydrophobic (oleylamine) and hydrophilic (polyethylene glycol) organic surfactants and their combination, as well. The attachment of modifiers to the TiO2 nanoparticles was proved via FT-IR and thermal analysis. Thicker modifier layer was formed on the TiO2 surface but lower average particle size was attained when amphiphilic modification was applied that was revealed by TEM analysis and dynamic light scattering, correspondingly. The amphiphilic modification permitted control of the hydrophobic properties of the TiO2 nanoparticles so that their incorporation in cement matrix led to preparation photocatalytic cement materials with superior De-NOx efficiency.

Amphiphilic poly(ether sulfone) membranes for oil/water separation: Effect of sequence structure of the modifier

Oil‐contaminated wastewater threatens our environment and health thus novel membrane materials with low or nonfouling properties are an immediate need for oily wastewater treatment in a cost‐effective and environmentally friendly manner. In this study, three types of amphiphilic random, gradient, and block copolymers with similar molecular weights and chemical compositions, based on poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3,3,4,4,5,5,6,6,7,7,8,8,8‐tridecafluorooctyl acrylate (TFOA), were synthesized by the reversible addition‐fragmentation chain transfer (RAFT) method. The amphiphilic Poly(ether sulfone) membranes were then fabricated by blending with these copolymers via a facile coupled process of nonsolvent induced phase separation and surface segregation. Accompanying the phase inversion process of polymer matrix, the hydrophilic and hydrophobic segments in the amphiphilic modifiers would migrate and immobilize onto the membrane surfaces. This surface segregation process leaded to a chemical heterogeneous membrane surface comprising both hydrophilic PEGMA and low surface energy PTFOA brushes, which was confirmed by X‐ray photoelectron spectroscopy (XPS) and surface wettability analyses. Oil‐in‐water emulsion filtration test of the membranes displayed a lower permeate flux decline and a higher flux recovery (as high as 99.8%), establishing their considerably elevated antifouling properties. Additionally, cyclic oil/water separation and long‐term underwater immersion tests demonstrated that the as‐prepared membranes modified by these amphiphilic additives possessed excellent antifouling stabilities. © 2016 American Institute of Chemical Engineers AIChE J, 63: 739–750, 2017