最新刊期
卷 ， 期 12 ， 2011
- 摘要：A novel of amphiphilic diblock copolymer (P(IBA-co-DMAEMA)-b-PHPA),which composed of poly(isobutyl acrylate-co-2-(N,N-dimethylamino)ethyl methacrylate) random copolymer block and poly(2-hydroxypropyl acrylate),was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization,and its structure and composition were confirmed by gel permeation chromatography (GPC),1H nuclear magnetic resonance (1H-NMR) spectroscopy and FTIR spectroscopy.This copolymer could self-assemble into stable polymeric micelles.The critical micelle concentration values of the self-assembled micelles were about 2.1 mg/L in distilled water relying on fluorescent probe technique.The results measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that the self-assembled P(IBA-co-DMAEMA)-b-PHPA micelles exhibited spherical core-shell structure with mean hydrodynamic diameter around 110~136 nm and uniform and narrow size distribution in aqueous media.The model drug folic acid (FA) was loaded into the micelles as drug carrier material and the in vitro drug release behavior was investigated at physiological conditions.We found that the FA-loaded content and the entrapment efficiency reached up to 38% and 76%,respectively.In phosphate buffer solution(PBS)at ionic strength I=0.15 kg/mol,temperatures T=37℃,and different pH=2.0, 7.4and 9.2,in vitro release rates of folic acid (FA) from polymeric micelles were all relatively faster within 40 h,and increased with pH value increase.Followed by slow release,the largest accumulation release percentage was 36%,61% and 80%,respectively.Thus,the polymeric micelles are expected to be a novel type of carrier material with pH-responsive and high drug loading capacity for drug delivery.关键词：Amphiphilic block copolymer;Micelles;Preparation;High drug-loaded capacity;Control of folic acid release
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发布时间：2021-03-19 - 摘要：B10H14 was prepared from NaBH4 via oxidation of B11H14-1,and the Lewis base acetonitrile attacked the high electron density vertices on the B10H14 cage to form the complex,6,9-bis-(acetonitrile)-decaborane.1,2-Bis-( acetoxymethyl ) carborane (BAMC) was obtained by the reaction of 6,9-bis-(aceto-nitrile)decaborane and 1,4-diacetyl-2-butyne,which was then hydrolyzed to form 1,2-bis(hydroxymethyl)-carborane (BHMC).Hydroxy-terminated polyester containing carborane was prepared via the condensation polymerization of 1,2-bis-(hydroxymethyl)carborane and adipyl chloride by controlling the molar ratios of diol and dichloride.The structures and purity of the monomers and polyester were confirmed by FTIR,1H-NMR,11B-NMR and element analysis.It was found that the11B-NMR of BAMC and BHMC was similar,which demonstrated carborane had high chemical stability.Two kinds of solvent-free polyurethane adhesives(PUA and PUB) were prepared based on carborane-polyester,N100 and PAPI,and their shear strength and thermal properties were determined.The results showed PUA and PUB could be used in the range of -150~200℃,and they could provide higher stability of adhesive joints to elevated temperatures than the normal PU adhesives.DSC showed that the exothermic peak of PUA appeared at 250℃,while the one of PUB appeared at 300℃,which demonstrated PUB had better thermal stability than PUA.The difference in properties of PUA and PUB derives from the different structures of curing agents.Therefore,introduction of carborane into PU adhesives not only retains the excellent low temperature resistance of PU,but also improves their thermal resistance.关键词：Decarborane;Carborane-polyester;Polyurethane adhesive;Curing agent;Thermal stability
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发布时间：2021-03-19 - 摘要：Non-colavent modification of multiwall carbon nanotubes (MWCNTs) by arylamides compound -nucleating agent (-NA) through - interaction was found to improve the dispersion of MWCNTs in the polypropylene (PP) matrix,increase the crystallinity of PP,decrease the crystal size,and increase the electrical conductivity of their composites.The morphology,crystallization behavior and the electrical conductivity of the nanocomposites were investigated by field emission scanning electron microscopy (FESEM),wide-angle X-ray diffraction (WAXD) and properties test.The characterizaiton of -NA-MWCNTs showed that -NA was successfully adsorbed on the surfaces of MWCNTs.The incorporation of -NA-MWCNTs results in the formation of rich -form crystals for PP,higher crystallinity and smaller crystalline sizes.FESEM observation showed that homogeneous compact network structure of -NA-MWCNTs was obtained due to the smaller and more uniform crystalline region.Consequently,the PP/-NA-MWCNTs nanocomposites possess a high electrical conductivity and a low percolation threshold of 0.3 wt% -NA-MWCNTs,which is associated with the homogeneous compact network structure of -NA-MWCNTs.The electrical conductivity of PP/-NA-MWCNTs (5 wt%) was up to 4.010-3 S/cm,which was 3 and 11 orders higher than that of PP/MWCNTs and PP,respectively.The effect of the crystalline size on the electrical conductivity of the nanocomposites was studied by isothermal crystallization method.The electrical conductivity of PP/-NA-MWCNTs was increased at first and then decreased with increasing time of isothermal crystallization.And the more MWCNTs added,earlier the maximum conductivity of PP/-NA-MWCNTs appeared.At the same content of MWCNTs,the isothermal time for the maximum conductivity at 140℃ was longer than that at 130℃.The results imply that high electrical conductivity with optimal MWCNTs network structure can be obtained by controlling the crystallization conditions.
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发布时间：2021-03-19 - 摘要：5-Chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the reaction between HQ and chloromethylation reagent 1,4-bichloromethoxy-butane (BCMB).The Friedel-Crafts alkylation reaction was carried out between CHQ and polystyrene (PS),and HQ was bounded onto the side chains of PS,obtaining the modified polystyrene HQ-PS.And then,the coordination reaction between HQ-PS and 8-hydroxyquinoline aluminum complex Alq2 that have two HQ ligands was conducted,and the luminous material Alq3-PS,on which 8-hydroxyquinoline aluminum complex Alq3 is attached chemically,was achieved,namely,the polymeric Alq3 was prepared.In order to fully characterize the chemical structure and properties of Alq3-PS,several characterization means were employed such as FTIR,1H-NMR,UV-Vis absorption spectrum and thermogravimetric analysis (TGA),and its luminous performance was determined.In this work,the effects of the main factors on the Friedel-Crafts alkylation reaction were investigated,and the reaction conditions were optimized.The experimental results show that the Friedel-Crafts alkylation reaction between PS and CHQ can proceed successfully,and the suitable reaction conditions are as follows: a temperature of 70℃,with N,N-dimethylformamide (DMF) as solvent,and using SnCl4 as Lewis catalyst.The Alq3-containing polystyrene,Alq3-PS,possesses the fluorescence-emission spectrum of Alq3 and has higher thermostability than polystyrene.关键词：8-Hydroxyquinoline aluminum;Polystyrene;Friedel-Crafts alkylation reaction;Fluorescence-emission
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发布时间：2021-03-19 - 摘要：Considering the apparatus with enormous size,the heat-sealing techniques are improved so that reaction apparatus can be not only movable but also fixed.Break-seal ampoules used frequently are modified to make the experimental operation safe and easy.A convenient method to fix the apparatus is used to ensure the safety of experiments because the constriction section of sealed apparatus can be broken easily.A novel method that complicated apparatus can be constructed with glass blowing of separated units of the apparatus is presented by detail description of purification procedures.关键词：High vacuum technique;Glass-blowing techniques;Modification of operation
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发布时间：2021-03-19 - 摘要：ABS particles with core-shell structure and nano-CaCO3 particles were employed to modify hard PVC simultaneously.The phase morphology and fracture behavior of the composites were investigated by means of transmission electron microscope (TEM),scanning electron microscope (SEM) and mechanical tests.Based on reasonable assumptions and material parameters obtained by the true stress-strain curve,finite element simulation employing the two-dimensional representative volume element model was carried out to explore the effects of ABS and CaCO3 particles on the fracture behavior of the composites.Results showed that ABS and CaCO3 particles have a synergistic toughening effect at nano-CaCO3 contents lower than 12 phr.The TEM observation revealed that the ABS particles deformed mainly by cavitation rather than interfacial debonding.The finite element analysis(FEA) results indicated that the blend yields when local yielding areas in the matrix begin to interconnect throughout the interstitial matrix between the particles.The predicted yield stresses for the PVC/ABS binary blend and the PVC/ABS/nano-CaCO3 ternary composite are consistent with experimental values.Moreover,the FEA results implied that both ABS and CaCO3 particles could toughen the PVC matrix,and the well-dispersed CaCO3 particles had a better toughening effect.If the CaCO3 particles are agglomerated,however,the large crevices between CaCO3 agglomerates and PVC matrix would initiate cracks at the interface and lead to decrease of mechanical properties.关键词：PVC;Nanocomposites;Fracture behavior;Finite element analysis
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发布时间：2021-03-19 - 摘要：A novel series of anionic fluorine-containing amphiphilic graft copolymers P(HFMA-co-NaSS)-g-PEG were synthesized by graft copolymerization of poly(ethylene glycol) methyl ether methacrylate (MPEGMA) macromonomer,2,2,3,4,4,4-hexafluorobutyl methacrylate (HFMA) and sodium 4-vinylbenzenesulfonate (NaSS).The molecular structures of the amphiphilic graft copolymer were characterized by FTIR,1H-NMR and 19F-NMR.The critical micelle concentration (CMC) of P(HFMA-co-NaSS)-g-PEG was measured by surface tension technique,indicating that the CMC increased gradually with increasing PEG branched chains and anionic contents in the copolymer.The average hydrodynamic diameter and size distribution of micelles were measured by dynamic light scattering (DLS).The measurement showed that the hydrodynamic diameter increased gradually with increasing the concentration of P(HFMA-co-NaSS)-g-PEG aqueous solution and the content of PEG branched chains in P(HFMA-co-NaSS)-g-PEG.The fluorescence spectrum showed that there was a significant interaction between P(HFMA-co-NaSS)-g-PEG micelles and bovine serum albumin (BSA).The fluorescence intensity of BSA decreased gradually in P(HFMA-co-NaSS)-g-PEG/BSA aqueous solution with increasing the concentration of P(HFMA-NaSS)-g-PEG aqueous solution,HFMA segments and NaSS contents.Transmission electron microscopy (TEM) was used to investigate P(HFMA-co-NaSS)-g-PEG micelles and the aggregates of P(HFMA-co-NaSS)-g-PEG/BSA,the results showed that P(HFMA-co-NaSS)-g-PEG copolymers could self-assemble into core-shell structure micelles.Besides,with the decrease of HFMA contents in the copolymer,the morphology of P(HFMA-co-NaSS)-g-PEG micelles changed from a leaf-like structure to a spherical one.In particular,when BSA was added,the micelles changed from a tight core-shell structure into a loose vesicle-like structure,and the micelle size and size distribution also increased.TEM micrographs of P(HFMA-co-NaSS)-g-PEG/BSA displayed a visible adsorption phenomenon between P(HFMA-co-NaSS)-g-PEG micelles and BSA,and suggested that P(HFMA-co-NaSS)-g-PEG may have potential applications in loading proteins and other bioactive drugs.关键词：Anionic;Amphiphilic graft copolymer;Micellization;Fluoropolymer;Fluorescence spectroscopy;Bovine serum albumin
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发布时间：2021-03-19 - 摘要：Four aminosilane compounds as external electron donors were synthesized and employed for 1-butene polymerization with MgCl2 supported Ziegler-Natta catalyst.The four aminosilane compounds are di(piperidinyl)dimethoxysilane (DPPDMS),di(piperidinyl)diethoxysilane (DPPDES),di(pyrrolidinyl)-dimethoxysilane (DPRDMS) and di(pyrrolidinyl)diethoxysilane (DPRDES).The effects of the structure of different external donors on the catalytic efficiency,isotacticity,melting temperature and molecular weight distribution of resulted poly(1-butene) were investigated in detail.Poly(1-butene)s have been characterized by using gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) analysis.The results indicated that the aminosilane compounds possessing dimethoxy groups showed higher catalytic efficiency and isospecificity of polymers than those of compounds having diethoxy groups,whereas the aminosilane compounds containing diethoxy groups were benefit for obtaining broader molecular weight distribution polymers than those of compounds possessing dimethoxy groups.Furthermore,compared with DPPDMS or TEOS as external donor,DPPDMS/TEOS compound as complex external donor at a proper molar ratio not only increased the catalytic efficiency and isotacticity of polymers obtained,but also broadened the molecular weight distribution of the polymer.Moreover,the effects of different amount of hydrogen and concentration of external donor and cocatalyst on catalytic efficiency and isotacticity of polymers obtained were also studied.关键词：Ziegler-Natta catalyst;External donors;Aminosilane compounds;Poly(1-butene)
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发布时间：2021-03-19 - 摘要：In order to solve the problem of the dispersion of bamboo fiber,the preparation of the surface treated bamboo fiber and polypropylene composite was carried out in reference to the way of papermaking.The fracture surface of the composite was characterized by the scanning electron microscope.The result showed: the processes of papermaking method solved the problem of the dispersion of bamboo fiber in the composite,and obtained the uniform bamboo fiber distribution of the bamboo fiber/PP composite materials. The composites which contained 25 wt% bamboo fiber were autoclave-foamed in a batch process in supercritical CO2 according to the heterogeneous nucleation mechanism using supercritical CO2 as physical blowing agents, and the influences of the foam process conditions (such as saturated pressure, saturated time and saturated temperature) on the bubble pore parameters were discussed. Using a scanning microscope,the cell structures of the foaming samples were also investigated,the result indicated: the bamboo fiber had a great positive impact on improving the cell morphology and the cell density.There would be uniform cell size and distribution in the bamboo fiber/PP composite foams.When a minimum bubble diameter was 5.24 m,the cell density reached a maximum,1.92 109 cells/cm3关键词：Supercritical CO2;PP;Bamboo fiber;Foam;Papermaking
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发布时间：2021-03-19 - 摘要：Poly(trimethylene terephthalate) (PTT)/poly(butylene terephthalate) (PBT) blend and its ternary systems reinforced by carbon nanotubes (CNTs) were prepared by melt-mixing.The effect of CNTs on the transesterification between PTT and PBT was then studied through nuclear magnetic resonance spectroscopy (NMR).The possible mechanisms were then discussed preliminarily according to the observations by transmission electron microscopy (TEM) scanning electron microscopy (TEM) and sedimentation experiments, as well as the results from other measurements such as rheology and dynamical thermal mechanical analysis (DTMA).The as-obtained PTT/PBT is a typical thermodynamical miscible blend system and,small amounts of tetrabutyl orthotitanate (Ti(OBu)4) can promote ester inter-change reactions between PTT and PBT components effectively.The addition of CNTs during melt mixing can further facilitate transesterification in the systems,resulting in evident decrease of the number-average length (LB and LT) of PTT-PBT copolymers and increase of the degree of randomness (B) of systems.This indicates that the CNTs can catalyze or even participate in the ester inter-chain reactions in the ternary systems.Such an effect,however,shows high dependence on the CNT loadings.With increasing CNTs loadings,the transesterification degree (Y) of ternary systems reduces gradually.关键词：Poly(trimethylene terephthalate);Poly(butylene terephthalate);Blends;Carbon nanotubes;Transesterification
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发布时间：2021-03-19 -
REDUCTIVE DEGRADATION OF LIGNIN IN SUPERCRITICAL SOLVENT AND APPLICATION IN PHENOLIC RESIN SYNTHESIS
摘要：The lignin was readily decomposed into phenol compounds via reductive liquefaction in supercritical ethanol media (formic acid decomposed into hydrogen at reaction temperatures),opening a promising opportunity to lignin-derived value-added aromatic compounds for highly possible application in phenol-formaldehyde resin production.The supercritical ethanol was the ideal reaction medium for lignin degradation,and the in situ generated hydrogen exactly promoted the decomposition reactions to smaller molecules via encapping the lignin radicals to terminate the further coupling and condensation.The liquefaction mechanism was radical thermal degradation.Some transition metal salts could catalyze the above lignin thermal decomposition,including nickel nitrate,cobalt nitrate and chloroplatinum acid.The yield of the lignin-degraded liquid increased with the increase of formic acid used in the ethanol solvent,while slightly deceased when the reaction temperature increased.The molecular weight of the lignin-derived liquid highly decreased with increase of the reaction temperature,e.g. at 350℃ the number average molecular weight was 143 while for the original lignin feedstock it was 588.The optimum reaction conditions are found to be ethanol-formic acid weight ratio at 1∶1; lignin load at 10 wt%; reaction temperature at 350℃for 4h.The lignin-derived phenols were characterized by GC-MS technique,and the liquefied product was mainly phenol derivatives with simple structures.Compared with the lignin,the bio-phenols possessed highly improved solubility and reactivity in phenol-formaldehyde synthesis.As the ideal replacement of industrial phenol,lignin-degraded bio-phenol was utilized readily in resol type phenolic resin production with a replacement higher than 50wt%.The thermal stability was slightly decreased with the increased amount of lignin-derived biophenol in the phenolic resin formula.The results showed the effective reductive degradation of lignin in supercritical ethanol would have a promising outlook in value-added phenol compounds and biomass-based renewable phenol-formaldehyde resins.关键词：Lignin;Decomposition;Reductive;Phenols;Phenolic resin- 43
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发布时间：2021-03-19 - 摘要：A group of novel mesogen jacketed mesomorphic polyacetylene containing terphenyl pendent groups with varying spacer lengths ({HC C[(CH2)mOOC-terpheyl-(OC6H13)2]}n,where m=5,PHA5TP-(OC6)2; m=9,PHA9TP(OC6)2) are synthesized by polymerization using [Rh(nbd)Cl]2 catalyst, and the structures and properties of the polymers are characterized and evaluated by IR,NMR,GPC,TGA,POM,DSC,XRD,UV and PL analyses. The effects of structural variations on the thermal,mesomorphic and luminescent properties were investigated by tuning the spacer length.The results show that the terphenyl mesogens endow the monomers and their polymers with good liquid crystalline behavior,and the monomers exhibit enantiotropic smectic C phases,while the polymers possess enantiotropic smectic A phases in the heating and cooling processes.The jacket effect from terphenyl mesogenic pendants at the waist position linked to the main chain contributes to the two polymers with high thermal decomposition temperature and excellent photoluminescence,which can lose almost no weight when they were heated above 370℃ and emit strong blue light at 410 nm when they were excited by the photons of 325 nm wavelength.In comparison with PHA5TP(OC6)2,the polymer with longer flexible spacer,PHA9TP(OC6)2,exhibits better liquid crystalline behavior,stronger UV light absorption and higher photoluminescence.关键词：Polyacetylenes;Liquid crystals;Photoluminescence
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发布时间：2021-03-19 - 摘要：Oxidative polymerizations of 2-(N,N-diethylamino)ethyl methacrylate (DEAEMA) as an intrinsically reducing inimer catalyzed by high-oxidation state transition metals (CuX2/ligand,FeX3/ligand,X=Cl or Br,ligand=2,2'-bipyridine,tetramethylethylenediamine,pentamethyldiethylenetriamine,CuSO4) were systematically investigated using gas chromatography,gel-peameation chromatography and multi-angle laser light scattering (MALLS) to monitor the monomer conversion,molecular weight (MW) and its distribution (MWD) of the PDEAEMA,respectively.The results showed that the high-oxidation state transition metals can steadily catalyze the free radical polymerization of DEAEMA with the reaction temperature ranging from 30℃ to 60℃ even in the absence of any chemical initiators,the MW of the PDEAMEA increased gradually with the conversion,while it maintained a rather broad MWD even from low conversions.The MALLS results showed that the absolute MW of the PDEAEMA showed an unusual multi-modal distribution.By comparing the CuSO4-catalyzed redox-initiation ability of lower-MW tertiary amines,it can be concluced that DEAEMA functions as an intrinsically reducing inimer under the catalysis of high-oxidation state transition metals,which oxidize the alpha CH (C-H) of the amine group of DEAEMA into the C radicals,initiating the conventional radical polymerization of DEAEMA and giving rise to linear PDEAEMA primary chains.Subsequently,the linear PDEAEMA chains serve as macro-initiators with high-oxidation state transition metals and initiate the graft polymerization of DEAEMA,leading to branched PDEAEMA with a certain number of side chains.It was inferred that self-initiated free radical polymerization of intrinsically reducing inimers under catalysis of high-oxidation state transition metals can produce long-chain-branched polymer via such a one-pot approach.关键词：2-(N,N-diethylamino)ethyl methacrylate;Intrinsically reducing inimer;Catalytic oxidative polymerization;Redox initiation
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发布时间：2021-03-19 - 摘要：A series of fluorinated acrylate copolymers were synthesized via free radical copolymerization by using monomers of 2-(perflurooctyl)ethyl methacrylate (FOEMA) and n-alkyl acrylates (RAs) (n=4, 8, 12, 16, 18) with various lengths of side chains. The crystalline behavior of the copolymers was characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). It is found that the crystallization of acrylate copolymers is in close connection with the side-chain length of acrylates. The copolymers crystallized at room temperature when the side-chain length number n was 16 or 18, however, no crystallization was observed for the copolymers with n less than 16 under the same condition. The crystallization enthalpy changes of RA-co-FOEMA copolymers were determined from the DSC thermograms. The copolymer with n=16 has the minimum entropy change at constant pressure compared with other three crystallized copolymers through thermodynamic calculation, which indicated this copolymer was the most ordered one. The F/C atomic ratios and composition of functional groups on the surfaces of RA/FOEMA copolymer films were determined by multifunctional photoelectron spectroscopy (XPS), and the static contact angles of n-hexadecane and water on films were measured. The F/C ratios increased from 0.39 to 0.71 with increase in the side-chain length of RA/FOEMA copolymers. When n was 16 or 18, the copolymers demonstrated much more composition of non-polar groups (CF3 and CF2) and fewer polar groups (C=O and COC=O) on the film surfaces, leading to the rapid increase in the n-hexadecane static contact angles on the films of copolymers. It may suggest that crystallization of hydrocarbon side-chain of copolymers can promote fluorinated component to migrate to the polymer-air interface during the process of film forming and hence improve the hydrophobicity and oleophobicity of the films.关键词：Fluorinated acrylate copolymers;Crystallization;Surface wetting properties;Hydrophobicity and oleophobicity
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发布时间：2021-03-19 - 摘要：Self-assembly of chitosan (CS) particles and poly(L-glutamic acid)-b-poly(propylene oxide)-b-poly(L-glutamic acid) (GPG) triblock copolymer micelles was investigated.The CS particles are cationic hydrogels,while the GPG micelles have anionic poly(L-glutamic acid) shells.Therefore,the two kinds of polyelectrolyte particles can electrostatic self-assemble into microscopic CS/GPG conjugates.The CS/GPG ratio range for the CS particles and GPG micelles to electrostatic self-assemble into a sustained CS/GPG conjugates solution was established.The CS/GPG conjugates were prepared by dropping CS particle solution into GPG micelle solution under stirring,with the CS/GPG ratio of 0.25/10,0.5/10,0.75/10,1.0/10,1.25/10,1.5/10,1.75/10 and 2/10.The CS/GPG conjugates are stable in water when the CS/GPG ratio is equal or less than 1.5/10.The particle size distribution of GPG micelles,CS particles,and CS/GPG conjugates were determined by the dynamic light scattering.GPG micelles show a narrow distribution with the average Rh of 59 nm,while the CS particles and CS/GPG conjugates show much broaden distributions with the Rh of 177 nm and 364 nm respectively.Zeta potential tests show that the GPG micelles exhibit surface negative charge of -52 mV and the CS particles exhibit surface positive charge of 22 mV.The surface charge of CS/GPG conjugates are negative and the average absolute value of the surface charge decreases with increasing CS amount.In vitro drug release behaviors of the Aspirin (Asp)-loaded CS particles,Doxorubicin (DOX)-loaded GPG micelles,and the Asp-CS/DOX-GPG conjugates (CS/GPG=1.5/10) were studied as a function of pH value.Both Asp and DOX show pH sensitive release behaviors in all the three drug-loaded systems.Moreover,the release rate of Asp shows a dramatic decrease in the Asp-CS/DOX-GPG system,as compared with the Asp-CS nanoparticles.关键词：Chitosan;Micelles;Electrostatic self-assembly;Multi-step self-assembly;Dual-drug delivery
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发布时间：2021-03-19 - 摘要：A novel surface molecularly imprinted polymer was synthesized using poly(vinyl alcohol) modified multi-walled carbon nanotubes (MWCNTs) as supporting matrix,ursolic acid (UA) as the template molecule,methacrylic acid (MAA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent.Effect of different molar ratios of the functional monomer to the template on the performance of the synthesized MWCNTs-MIPs was discussed and the results showed that the optimum ratio was 4∶1.The multi-walled carbon nanotubes-molecularly imprinted polymers (MWCNTs-MIPs) were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The results showed that a stable imprinted layer was grafted on the MWCNTs surface successfully.The adsorption properties were demonstrated by static adsorption and adsorption kinetic experiments.The results demonstrated that the MWCNTs-MIPs had specific selectivity for UA,yielding a maximum adsorption capacity of 53.1 mol/g and the equilibrium time took about 60 min.Solid phase extraction condition was optimized,and the optimal condition was washing with 100% methanol and eluting with 10% acetic acid methanol solution. The solid-phase extraction column packed with MWCNTs-MIPs could be applied to separate ursolic acid (UA) from similar structure oleanolic acid (OA).关键词：Surface molecular imprinting;Carbon nanotubes;Solid-phase extraction;Ursolic acid
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发布时间：2021-03-19
Research Article
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