Double open mouse-like terpyridine parts based amphiphilic ionic molecules displaying strengthened chemical adsorption for anticorrosion of copper in sulfuric acid solution

In this study,the benign target double terpyridine parts based amphiphilic ionic molecules(AIMs 1,2)and the reference single terpyridine segment included AIMs(AIMs 3,4)were synthesized through a multi-step method,and the molecular structures were fully characterized.The excellent anticorrosion of the target AIMs for copper surface in H_(2)SO_(4) solution was demonstrated by the electrochemistry analysis,which was more superior over those of the reference AIMs.The standard adsorption free energy changes of the target AIMs calculated by the adsorption isotherms were lower than -40 kJ·mol^(-1),suggesting an intensified chemical adsorption on metal surface.The molecular modeling and molecular dynamic computation of the studied AIMs were performed,demonstrating that the target AIMs exhibited lower highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps and greater adsorption energies than the reference ones.The chemical adsorption of the AIMs on metal surface was revealed by various spectroscopic methods including scanning electron microscopy,atomic force microscopy,Fourier transform infrared spectroscopy,attenuated total reflection infrared spectroscopy,Raman and X-ray diffraction.

SYNTHESIS AND CHARACTERIZATION OF AMPHIPHILIC GRAFT COPOLYMER CONTAINING MICROPHASE SEPARATED AND LONG POLY(ETHYLENE OXIDE) SIDE CHAIN STRUCTURES

Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.

Amphiphilic sodium alginate-vinyl acetate microparticles for drug delivery

To overcome the fast or burst release of hydrophilic drugs from hydrophilic alginate-based carriers,hydrophobic molecule(vinyl acetate,VAc)was grafted on alginate(Alg),which was further used to prepare drug carriers.Amphiphilic Alg-g-PVAc hydrogel beads were firstly prepared by emulsification/internal gelation technique for the loading of bovine serum albumin(BSA).Then,chitosan was coated on the surface of beads to form novel amphiphilic Alg-g-PVAc/chitosan(Alg-g-PVAc/CS)microcapsules.The BSA-loading amphiphilic Alg-g-PVAc/chitosan(Alg-g-PVAc/CS)microcapsules display similar morphology and size to the hydrophilic alginate/chitosan(AC)microcapsules.However,the drug loading and loading efficiency of BSA in Alg-g-PVAc/CS microcapsules are higher,and the release rate of BSA from Alg-g-PVAc/CS microcapsules is slower.The results demonstrate that the introduction of hydrophobic PVAc on alginate can effectively help retard the release of BSA,and the higher degree of substitution is,the slower the release rate is.In addition,the complex membrane can also be adjusted to delay the release of BSA.As a whole,amphiphilic sodium alginate-vinyl acetate/CS microparticles could be developed for macromolecular drug delivery.

Synthesis and characterization of H-type amphiphilic liquid crystalline block copolymers by ATRP

H-type amphiphilic liquid crystalline block copolymers containing azobenzene were synthesized by atom transfer radical polymerization （ATRP）. Macroinitiators prepared by the esterification between poly（ethylene oxide） （PEG） and 2,2-dichloroacetyl chloride were utilized to initiate the polymerization of 6-[4-（4-ethoxyphenylazo）phenoxy]hexyl rnethacrylate （M6C）. The resulting macroinitiators and block copolymers were characterized by ^1H NMR, gel permeation chromatography （GPC）. Polarizing optical microscopy （POM） and differential scanning calorimetry （DSC） preliminarily revealed the liquid crystalline property of these block copolymers. This series of liquid crystalline block copolymers are promising in some areas, such as optical data storage, optical switch, and molecular devices.

NOVEL AMPHIPHILIC FLUORESCENT GRAFT COPOLYMER: SYNTHESIS, CHARACTERIZATION AND ENCAPSULATION OF A HYDROPHOBIC AGENT

Novel amphiphilic fluorescent graft copolymer （PVP-PyAHy） was successfully synthesized by the free radical copolymerization of hydrophobic monomer N-（1-pyrenebutyryl）-N＇-acryloyl hydrazide （PyAHy） with hydrophilic precursor polymers of vinyl-functionalized poly（N-vinylpyrrolidone） （PVP） in DMF. The copolymer is amphiphilic and has intrinsic fluorescence. FT-IR, ^1H-NMR, TEM, gel permeation chromatography-multi-angle laser light scattering, UV-Vis spectroscopy and fluorescence spectroscopy were used to characterize this copolymer. The TEM observation shows that the copolymer PVP-PyAHy forms micelles in aqueous solution. Results of fluorometric measurements illustrate that the critical micelle concentration （CMC） value of PVP-PyAHy in aqueous solution is about 0.90 mg/mL. To examine the encapsulation ability of the copolymer in aqueous media, methyl yellow was employed as a model hydrophobic agent. The loading level of the polymer to methyl yellow is 8.8 mg/g. The cytotoxicity assays for Madin Darby Canine Kidney （MDCK） cells shows good biocompatibility of PVP-PyAHy in vitro. These results suggest the potential of this copolymer PVP-PyAHy as drugs delivery carrier and fluorescent tracer.

SYNTHESIS OF AMPHIPHILIC COMB-SHAPED COPOLYMERS USED FOR SURFACE MODIFICATION OF PVDF MEMBRANES

The synthesis of a novel amphiphilic comb-shaped copolymer consisting of a main chain of styrene-(N-(4- hydroxyphenyl) maleimide)(SHMI) copolymer and poly(ethylene glycol) methyl ether methacrylate(PEGMA) side groups was achieved by atom transfer radical polymerization(ATRP).The amphiphilic copolymers were characterized by ~1H-NMR, Fourier transform infrared(FTIR) spectroscopy and gel permeation chromatography(GPC).From thermogravimetric analysis (TGA),the decomposition temperature of SHMI-g-PEGMA is lower ...

New modular platform based on multi-adjuvanted amphiphilic chitosan nanoparticles for efficient lipopeptide vaccine delivery against group A streptococcus

An effective vaccine against group A streptococcus(GAS)is highly desirable for definitive control of GAS infections.In the present study,two variants of amphiphilic chitosan nanoparticles-based GAS vaccines were developed.The vaccines were primarily composed of encapsulated KLH protein(a source of T helper cell epitopes)and lipidated M-protein derived B cell peptide epitope(lipoJ14)within the amphiphilic structure of nanoparticles.The only difference between themwas one of the nanoparticles vaccines received additional surface coating with poly(I:C).The formulated vaccines exhibited nanosized particles within the range of 220–240 nm.Cellular uptake study showed that nanoparticles vaccine without additional poly(I:C)coating has greater uptake by dendritic cells and macrophages compared to nanoparticles vaccine that was functionalized with poly(I:C).Both vaccines were found to be safe in mice and showed negligible cytotoxicity against HEK293 cells.Upon immunization in mice,both nanoparticle vaccines produced high antigen-specific antibodies titres that were regulated by a balanced Th1 and Th2 response compared to physical mixture.These antibodies elicited high opsonic activity against the tested GAS strains.Overall,our data demonstrated that amphiphilic chitosan nanoparticles platform induced a potent immune response even without additional inclusion of poly(I:C).

AMPHIPHILIC STAR-BLOCK COPOLYMERS BY IODIDE-MEDIATED RADICAL POLYMERIZATION

Amphiphilic star-block copolymers composed of polystyrene and poly（acrylic acid） were synthesized by iodide- mediated radical polymerization. Firstly, free radical polymerization of styrene was carried out with AIBN as initiator and 1,1,1-trimethyolpropane tri（2-iodoisobutyrate） as chain transfer agent, giving iodine atom ended star-shaped polystyrene with three arm chains, R（polystyrene）3. Secondly, tert-butyl acrylate was polymerization using polystyrene obtained as macro-chain transfer agent, and star-block copolymer, R（polystyrene-b-poly（tert-butyl acrylate））3 with controlled molecular weight was obtained. Finally, amphiphilic star-block copolymer, R（polystyrene-b-poly（acrylic acid））3 was obtained by hydrolysis of R（polystyrene-b-poly（tert-butyl acrylate））3 under acidic condition.

Structural Multiplicity of Monomers of an Amphiphilic Porphyrin at the Outer Surface of CTAB Micelle

A synthesized amphiphilic porphyrin, 5,10,15-tri(p-hydroxyphenyl)-20-(p-hexadecyloxyphenyl) porphyrin, can take a transfer process for the porphyrin moiety from the inner core to the outer surface laver of cetyltrimethylammonium bromide (CTAB) micelle. The increasing of FWHH of the Sorer band was attributed to the multiplicity of porphyrin monomers related with deprotonation degree, arrangement, orientation, and position of porphyrin moiety at the surface al ea rather than the aggregates associated with irregular orientation of neighboring porphyrins.

STUDIES ON SELF-ASSOCIATIVE BEHAVIOR OF A NOVEL CATION AMPHIPHILIC POLYMER

A novel associating polymer P(AEBA) was synthesized by radical polymerization of the cationic amphiphilic monomer,4-(2-(acryloyloxy)ethoxy)benzyl tri-ethyl ammonium bromide(AEBA),in aqueous solutions.P(AEBA) displays a strong tendency for self-association in aqueous solutions and is sensitive to the external stimulation such as added salt.The associative properties and morphologies of P(AEBA) were studied by fluorescnece probe technique,viscometry and TEM.In dilute salt-free solutions P(AEBA) behaves as pol...

Amphiphilic Poly (3-Hydroxy Alkanoate)s: Potential Candidates for Medical Applications

Poly (3-hydroxy alkanoate)s, PHAs, have been very attractive as biomaterials due to their biodegradability and biocompatibility. These hydrophobic natural polyesters, PHAs, need to have hydrophilic character particularly for drug delivery systems. In this manner, poly (ethylene glycol) (PEG) and hydrophilic functional groups such as amine, hydroxyl, carboxyl and sulfonic acid have been introduced into the PHAs in order to obtain amphiphilic polymers. This review involves in the synthesis and characterization of the amphiphilic PHAs.

CONTROLLED SYNTHESIS OF AMPHIPHILIC BLOCK POLYMERS HAVING GLUCOSE RESIDUES AND THEIR STRUCTURE FORMATION

Vinyl ether (VE)-based amphiphilic block copolymers with D-glucose residues as hydrophilicpendants were synthesized by CH_3 CH(OiBu)Cl/ZnI_2-initiated sequential living cationic copolymerization of3-O-(vinyloxy)ethyl-1, 2:5, 6-di-O-isopropylidene-D-glucofuranose (IGVE) and isobutyl VE (IBVE ) andsubsequent deprotection. The precursor block copolymers had a narrow molecular weight distribution(M_w/M_n～1.1) and a controlled segmental composition. The solubility characteristics of the amphiphiliccopolymer depended strongly on composition. Their solvent-cast thin films were examined, under atransmission electron microscope, and could be seen to exhibit various microphase-separated surfacemorphologies such as spheres, cylinders, and lamellae, depending on composition. The amphiphiliccopolymers with the appropriate segmental composition were found to form a stable monolayer at the air-water interface, which was successfully transferred onto a substrate by the Langmuir-Blodgett (LB)technique. The layered strucfure of the built-up LB films was controlled by blending the homopolymer.

SYNTHESIS， SURFACE POTENTIAL AND NONLINEAR OPTICAL PROPERTIES OF NEW AMPHIPHILIC PORPHYRINS

A new kind of amphiphilic porphyrin containing only one carboxyl on the β point of porphyrin ring was synthesized. The surface potential and SHG (Second Harmonic Generation) efficiency of monolayer were measured and the relationship between the surface potential,SHG and the structure of molecule was discussed.

Preparation of Nano-porous Materials(Ⅱ) by Cross-linking of Amphiphilic Self-assemblies

Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.

Amphiphilic Polyphosphazene with Poly(ethylene oxide) Side Chains Prepared through the Decker-Forster Reaction

Poly （4- methylphenoxyphosphnzene ） -graft-poly （ ethylene oxide ） （ PPZ-g- PEO ）, a novel amphiphilie grafting polymer was prepared via the Decker-Forster reaction. It is found that the graft efficiency increased with extension of reaction time. Low molecular weight of poly （ ethylene oxide ） favored the grafting reaction. The grafted polymer has two different glass transition temperatures（ Tg） with those of pure poly（ 4-methyl- phenoxy-phopsphazene ） and PEO. The emulsifying ability of grafted polymer was studied with benzene-water mixtare. The emulsifying volumes increased with the decreasing of PEO＇ s molecular weight. The contact angle of film forming from grafted polymer decreased after introduction of PEO grafting chain.

SYNTHESIS OF AN AMPHIPHILIC PPESK-g-P(PEGMA)GRAFT COPOLYMER VIA ATRP AND ITS USE IN BLEND MODIFICATION OF PPESK MEMBRANES

Preparation of an amphiphilic graft copolymer having poly(phthalazinone ether sulfone ketone)(PPESK) as main chains was carried out by atom transfer radical polymerization(ATRP).The precursor,chloromethylated PPESK (CMPPESK),was prepared by using chioromethylether as chloromethylation agent.Then,poly(ethylene glycol) methyl ether methacrylate(PEGMA) was used as monomer to synthesize PPESK-g-P(PEGMA) by ATRP method under the catalysis of a cuprous chloride/2,2'-bipyridyl system.PPESK/PPESK-g-P(PEGMA) blend m...

Study of the reinforced mechanism of fly ash on amphiphilic polymer gel

Amphiphilic polymer gels are widely used in heterogeneous reservoirs for conformance control technology.However,in high temperature and high salinity of calcium and magnesium reservoirs,amphiphilic polymer gels cannot maintain effective performance.In this work,a novel reinforced amphiphilic polymer gel(F-PADC gel)was prepared by physically mixing polymer solution and fly ash(FA),which is an extremely low cost material.The viscoelasticity and stability of the F-PADC gel were studied by rheometry and micro-rheometry.The reinforced mechanism of FA on amphiphilic polymer gels was revealed.The results show that the addition of FA can make the gel more robust with a denser network structure.On the fifth day,the elastic modulus(G’)increases from 5.2 to 7.0 Pa and the viscosity modulus(G")increases from 0.4 to 0.6 Pa at the frequency of 1 Hz,which improves the viscoelasticity of the gel system.More importantly,the F-PADC gel does not degrade after aging at 85℃for 180 d.And its viscoelasticity increases obviously,G′and G"increase to 110.0 Pa and 3.5 Pa,respectively,showing excellent anti-aging stability.Moreover,FA amphiphilic polymer gels have a good injectivity and a perfect plugging rate of 98.86%,which is better than that of sole amphiphilic polymer gels.This novel mixed FA amphiphilic polymer gels can prove to be a better alternative to conventional polymer gels to enhance oil recovery in high temperature and high salinity reservoirs.

Synthesis and aggregation properties of amphiphilic mono and bisadducts of fullerene in aqueous solution

New amphiphilic[60]fullerene monoadduct TPF and bisadducts BTPF were synthesized and well-characterized. Their aggregation properties in aqueous solution was investigated by UV-vis and TEM methods. In aqueous solution, monoadduct TPF forms irregularly shaped and some rod-like aggregates, whereas bisadducts BTPF gives sphadcal aggregates with diameters of 50-150 rim. It indicated that the aggregation properties of amphiphilic fullerene derivatives depend on the number of hydrophilic

Molecular dynamics simulations of membrane deformation induced by amphiphilic helices of Epsin,Sar1p,and Arf1

The N-terminal amphiphilic helices of proteins Epsin, Sarlp, and Arfl play a critical role in initiating membrane deformation. The interactions of these amphiphilic helices with the lipid membranes are investigated in this study by combining the all-atom and coarse-grained simulations. In the all-atom simulations, the amphiphilic helices of Epsin and Sarlp are found to have a shallower insertion depth into the membrane than the amphiphilic helix of Arfl, but remarkably, the amphiphilic helices of Epsin and Sat lp induce higher asymmetry in the lipid packing between the two monolayers of the membrane. The insertion depth of amphiphilic helix into the membrane is determined not only by the overall hydrophobicity but also by the specific distributions of polar and non-polar residues along the helix. To directly compare their ability to deform the membrane, the coarse-grained simulations are performed to investigate the membrane deformation under the insertion of multiple helices.

Synthesis and characterization of a novel amphiphilic biodegradable β-cyclodextrin/poly(γ-benzyl L-glutamate) copolymer

β-Cyclodextrin/poly（γ-benzyl L-glutamate） （β-CD-PBLG） copolymers were synthesized by ring-opening polymerization of N- carboxy-γ-benzyl L-glutamate anhydride （BLG-NCA） in N,N-dimethylformamide （DMF） initiated by mono-amino-β-cyclodextrin（H2N-β-CD）. The structures of the copolymers were confirmed by IR, ^1H NMR and GPC. The fluorescence technique was used to determine the critical micelle concentrations （CMC） of copolymer micell solution, the diameter and the distribution of micelles were characterized by DLS. The results showed that BLG-NCA could be initiated by H2N-β-CD to produce copolymer. The nanomicells were formed by these copolymers in water.