首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The influence of molecularly imprinted polymer‐methacrylic acid functionalized β‐cyclodextrin (MIP(MAA‐β‐CD)) morphology on the adsorption behavior studies towards benzylparaben (BzP) was explored. The effects of time, concentration, and temperature towards BzP uptake were extensively evaluated. The adsorption performance of MIP(MAA‐β‐CD) was compared with that on the molecularly imprinted polymer‐methacrylic acid (MIP(MAA)) synthesized without β‐CD. The MIP(MAA‐β‐CD) was synthesized to obtain a spherical and spongy‐porous texture with a broad pore size distribution. The MIP(MAA‐β‐CD) showed fast kinetic and the intra‐particle diffusion model demonstrated a three step (surface and pore) adsorption process. The Koble‐Corrigan isotherm was the most suitable model for data fitting, which indicated that MIP(MAA‐β‐CD) had homogeneous and heterogeneous surfaces. This finding clearly demonstrated that the large uptake and strong affinity of MIP(MAA‐β‐CD) did not only probably result from the monomer‐template interactions, but also due to the morphological MIP(MAA‐β‐CD) structure. In contrary to MIP(MAA‐β‐CD), MIP(MAA) synthesized with uniform morphology and narrow pore size distribution had lower adsorption capacities and its kinetic data fitted the pseudo‐second order diffusion model, indicating a two‐step (surface only) adsorption process. The MIP(MAA) adsorption process followed the Langmuir isotherm model referred to solely homogeneous uptake. The calculated thermodynamic parameters showed that the BzP uptake was exothermic, spontaneous, and physisorption process onto MIPs, which supported the results of kinetics and isotherm adsorption data. This study clearly revealed that the presence of β‐CD improved the morphology of synthesized MIP, and automatically enhanced the adsorption behavior of MIP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42720.  相似文献   

2.
Water‐compatible molecularly imprinted polymers (MIPs) for caffeine were synthesized in aqueous medium with a new functional monomer, 1‐(α‐methyl acrylate)‐3‐methylimidazolium bromide (1‐MA‐3MI‐Br), which had π–π and hydrogen‐bonding interactions. Caffeine‐imprinted polymers were prepared in suspension polymerization with 1‐MA‐3MI‐Br and methacrylic acid (MAA), which only had hydrogen bonding, as a functional monomer. For the specific binding characteristics of the new functional monomer 1‐MA‐3MI‐Br, the adsorption capacity and relative separation factor (β) of MIPs for caffeine were significantly enhanced. The maximum adsorption capacities of 1‐MA‐3MI‐Br–MIP and MAA–MIP imprinted microspheres for caffeine were 53.80 and 28.90 μmol/g, respectively. Moreover, the relative separation factors were measured by comparison of the separation characteristics under competitive adsorption conditions. The results showed that the β of MAA–MIP for caffeine relative to theophylline was only 1.65; this showed a very poor recognition selectivity for caffeine, but β of 1‐MA‐3MI‐Br–MIP for caffeine with respect to theophylline was remarkably enhanced to 3.19; this showed an excellent recognition selectivity and binding affinity toward caffeine molecules in an aqueous environment. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

3.
Inspired from the highly bioadhesive performance of mussel protein, a simple, yet efficient synthetic method for efficiently imprinting of Artemisinin (Ars) was developed to prepare the bio‐inspired molecularly imprinted membranes (MIMs) via atom transfer radical polymerization (ATRP). In this work, attributed to the unique properties of polydopamine (pDA) modified layers and ATRP technology, the uniform recognition sites for efficiently selective extraction of the Ars with high stability could be obtained on the MIMs surfaces. In addition, the maximum adsorption capacity of the MIMs is 158.85 mg g?1 by the Langmuir isotherm model, which is remarkable higher than NIMs. Additionally, because of the formation of the uniform specific recognition cavities on membrane surfaces, the as‐prepared MIMs exhibited a rapid adsorption dynamics and well‐fitted for the pseudo‐second‐order rate equation, also, possessed an excellent per‐selectivity performance (βartemether/Ars values is 0.18) of template molecule, which clearly demonstrated the potential value of this method in the selective separation and purification of Ars. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43405.  相似文献   

4.
In this work, magnetic molecularly imprinted polymers (MMIPs) were used as novel adsorbents for selective adsorption of 3‐methylindole from model oil. The MMIPs were synthesized by precipitation polymerization and surface molecularly imprinted technique, using Fe3O4 nanoparticles as magnetically susceptible component, methylacrylic acid as dressing agent and functional monomer, ethylene glycol dimethacrylate as crosslinker, and 3‐methylindole as template molecule. The MMIPs were characterized by Fourier‐transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometer, and thermogravimetric analyzer, respectively. The adsorption performances of MMIPs were investigated by batch adsorption experiments in terms of kinetics, isotherms, and selective recognition adsorption, respectively. The results indicate that MMIPs have high recognition ability and fast binding kinetics for 3‐methylindole. Meanwhile, the adsorption equilibrium time was about 2 h and the equilibrium adsorption amount was ~38 mg g?1 at 298 K. The heterogeneous MMIPs were modeled with pseudo‐second‐order and Langmuir isotherm equation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2859–2866, 2013  相似文献   

5.
Novel, temperature‐responsive molecularly imprinted polymers (TMIPs) based on potassium hexatitanate whiskers for selectively adsorbing sulfadiazine (SDZ) from aqueous media were prepared with methacrylic acid (MAA) and 4‐vinylpyridine (4‐VP) as cofunctional monomers and N‐isopropyl acrylamide (NIPAM) as a temperature‐responsive monomer. The template–monomer interactions were studied by molecular simulation. In particular, the effects of different kinds of crosslinkers on the selective recognition ability of the TMIPs in water media were investigated. The temperature–responsive adsorption performance and phase behavior of the molecularly imprinted polymers were studied by batch‐mode binding experiments, swelling experiments, and contact angle testing. The results demonstrate that the combination of MAA, 4‐VP, and NIPAM was a favorable temperature‐responsive imprinted system for SDZ in water, and the cocrosslinking agent of ethylene glycol dimethacrylate (EGDMA) and N,N′‐methylene bisacrylamide (MBA) was more suitable compared with either pure EGDMA or MBA. The adsorption kinetics and adsorption isotherms were analyzed by the fitting of different adsorption models. Also, the effect of the temperature on the recovery was investigated by the determination of the spiked SDZ in real‐water samples with solid‐phase extraction and high‐performance liquid chromatography. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41769.  相似文献   

6.
An azobenzene‐containing molecularly imprinting polymer microsphere with photoresponsive binding properties toward 2,4‐dichlorophenoxyacetic acid (2,4‐D) was successful prepared via silica surface polymerization. The number‐average diameters of silica and imprinting polymer microsphere are 0.5 and 0.7 μm, respectively. The static adsorption, binding and selectivity experiments were performed to investigate the adsorption properties and recognition characteristics of the polymers for 2,4‐D. The equilibrium adsorptive experiments indicated that 2,4‐D‐SMIP(surface molecularly imprinted polymers) has significantly higher adsorption capacity for 2,4‐D than its nonimprinted polymers (SNIP).The binding constant Kd and apparent maximum number Qmax of the imprinted polymer were determined by Scatchard analysis as 0.054 mmol L?1 and 0.167 mmol g?1, respectively. The result of photoregulated release and uptake of 2,4‐D experiment demonstrated that azo‐containing SMIP can make use of light and change it into mechanical properties to release and take up the template molecules. It means that the SMIP can be controlled by light. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 869‐876, 2013  相似文献   

7.
The molecular imprinting technique is a new method for preparing molecularly imprinted polymers (MIPs) with specific molecular recognition sites for certain target molecules. In this study, a novel, facile preparation method was presented, called “seed precipitation polymerization,” for the synthesis of MIPs via surface imprinting and a support matrix. In the polymerization process, kaempferol was used as the template molecule, methacrylic acid as the functional monomer, nano‐TiO2 as the support, azodiisobutyronitrile as the initiator, and ethylene glycol dimethacrylate as the crosslinker in acetonitrile solvent. The synthesized T‐MIP and MIP were analyzed by infrared spectroscopy and scanning electron microscopy. In addition, the obtained polymers were evaluated by adsorption isotherms and dynamic curves for their selective recognition properties for kaempferol. The results show that T‐MIP shows regular spherical particles; the adsorption dynamic curves of T‐MIP show that the adsorption capacity increases with time and reaches a maximum value and then finally reaches equilibrium, and the T‐MIP exhibits a higher affinity for kaempferol than does the MIP. The adsorption follows pseudo‐second‐order kinetics, the Freundlich adsorption equation fits the experimental data well, and there is strong evidence for multiple‐layer adsorption. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44888.  相似文献   

8.
Bulk and microemulsion systems were studied in order to obtain molecularly imprinted copolymers selective for gallic acid. Both systems contained acrylic acid as the functional monomer and ethylene glycol dimethacrylate as crosslinker. Microemulsion formation was confirmed by refractive index measurements and by conductivity analyses. Simple uptake tests revealed higher affinities for the microemulsion polymers; a 3.55 imprinting factor and a 0.275 g gallic acid (g polymer)–1 adsorption capacity were recorded. Competitive uptake tests, from an oak bark extract, were in agreement with the simple uptake results and BET analyses. Microemulsion polymer particles selectively bind 4.58 times more gallic acid molecules relative to other competitor species.  相似文献   

9.
A surface imprinted core‐shell nanorod with water‐compatible property was first prepared, using a two‐step “living” polymerization technique, with magnetic attapulgite (MATP) as core, and it was applicable in the enhanced selective removal of sulfamethazine residue from pure water environments. MATP was synthesized by an impregnation and pyrolysis method, and polymerable group was subsequently attached onto the surface. The imprinted polymer nanoshell (13 nm) with the “living” fragments was formed via a reverse atom transfer radical precipitation polymerization, avoiding the tedious graft of initiator and providing the easy‐accessible imprinted sites. Ultrathin hydrophilic polymer brushes (2.0 nm) were surface‐grafted to improve their water‐compatibility. The nanoadsorbent exhibited good thermal stability, magnetism, and hydrophilicity through characterization. The nanoadsorbent showed large adsorption capacity toward sulfamethazine from water, which increased with the increase of contact temperature. Langmuir isotherm fitted the equilibrium data better, and the kinetic data (within 45 min) were well‐analyzed by the pseudo‐second‐order kinetic model. Also, the specific adsorption property of the nanoadsorbent was greatly improved through the surface‐grafting, which exhibited excellent selectivity to sulfamethazine compared with other reference antibiotics. Efficient magnetic separation and good reuse of the nanoadsorbent provided the potential possibility for selective recognition and fast removal of antibiotic pollutions from water environments. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40854.  相似文献   

10.
Herein, we report a magnetic molecularly imprinted polymers (m‐MIPs) using Fe3O4 as a magnetic component, carvedilol as a template molecule for the solid‐phase extraction (MISPE) as the sample clean‐up technique combined with high‐performance liquid chromatography (HPLC) and for the controlled release of carvedilol at different pH values of 1.0 (simulated gastric fluid), 6.8 (simulated intestinal fluid), and 7.4 (simulated biological fluid). The adsorption kinetics was modeled with the pseudo‐first‐order and pseudo‐second‐order kinetics, and the adsorption isotherms were fitted with Langmuir and Freundlich models. The performance of the m‐MIPs for the controlled release of carvedilol was assessed and results indicated that the magnetic MIPs also have potential applications in controlled drug release. Furthermore, the m‐MIPs were applied to the extraction of carvedilol from human blood plasma samples. Carvedilol can be quantified by this method in the 2–350 μg L?1 concentration range. The limit of detection and limit of quantification in plasma samples are 0.13 and 0.45 μg L?1. The results from HPLC showed good precision (3.5% for 50.0 μg L?1) and recoveries (between 85 and 93) using m‐MIP from human plasma samples. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41209.  相似文献   

11.
To enhance the affinity of 4‐vinyl pyridine to l ‐phenylalanine (l ‐Phe) and convert the imprinting process from the aqueous phase to the organic phase, an oil‐soluble amino acid ionic liquid was introduced as a template. In this study, 1‐butyl‐3‐methylimidazolium α‐aminohydrocinnamic acid salt was first applied to prepared surface molecularly imprinted polymers (MIPs) in acetonitrile for the selective recognition of l ‐Phe. Fluorescence quenching analysis of the functional monomer on the template was investigated under different conditions to study the imprinting mechanism. Several binding studies, such as the sorption kinetics, sorption thermodynamics, and solid‐phase extraction application, and the chiral resolution of racemic phenylalanine were investigated. The binding isotherms were fitted by nonlinear regression to the Freundlich model to investigate the recognition mechanism. The affinity distribution analysis revealed that polymers imprinted by ionic liquid showed higher homogeneous binding sites than those imprinted by l ‐Phe. The competition tests were conducted by a molecularly imprinting solid‐phase extraction procedure to estimate the selective separation properties of the MIPs for l ‐Phe. The target MIP was shown to be successfully for the separation of l ‐Phe from an amino acid mixture. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42485.  相似文献   

12.
On account of the high toxicity of nitrobenzene, 1,2‐dichloroethane was used as solvent. A novel water‐compatible hyper‐cross‐linked resin functionalized with amino‐group (denoted as GQ‐04) was synthesized to remove salicylic acid (SA) in aqueous solution. The maximum adsorption capacity of SA onto GQ‐04 was observed at pH of 1.88. The adsorption capacity increased with the increasing salt concentration. The adsorption kinetic data obeyed the pseudo‐second‐order rate equation and the adsorption isotherms can be characterized by Freundlich model. The intraparticle diffusion was the main rate‐controlling step. The saturated adsorption quantity of SA was up to 119.9 mg·mL‐1 according to the dynamic adsorption at 293 K. The resin could be regenerated by the 6 BV mixed solution of 80% ethanol and 0.5 mol/L NaOH. The size matching and hydrogen bonding between GQ‐04 and SA and the micropore structure resulted in the larger adsorption capacity in comparison with XAD‐4 and H103 resin. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

13.
The purpose of this study is to develop a stimuli‐responsive hybrid polymer gel system with an improved mechanical stability as a controlled drug delivery carrier that can undergo phase transition by the stimulation of ethanol–water mixture. For this aim, trimethoxysilane terminated poly(propylene glycol) by coupling of 3‐isocyanatopropyl‐triethoxysilane with the hydroxyl end groups of poly(propylene glycol) through urethane bonds was synthesized. Hybrid polymer gels prepared in the presence of tryptophan (Trp), as a model of drug, were characterized and gelation time of polymer network was obtained by monitoring the fluorescence emission of Trp in pre‐gel solution. Swelling, solvent uptake and release kinetic of polymer gels were evaluated depending on time. The diffusional exponents (n) and diffusion constants (k) of each gel were calculated by using the swelling kinetic data. The effect of precursors as a monomer on Trp release profile was analyzed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42913.  相似文献   

14.
A composite of reduced graphene oxide and pyrene‐imprinted polymer was synthesized and employed as a solid phase for extraction of five selected polycyclic aromatic hydrocarbons (PAHs) from water samples. Gas chromatography‐time of flight/mass spectrometry was employed in the analysis of the extracts. The composite was prepared by a free radical polymerization of methacrylic acid and 4‐vinylpyridine as monomers and ethylene glycol dimethacrylate as a crosslinker. The adsorption studies were carried out through batch binding studies. The binding capacity for the imprinted and non‐imprinted composite was 101.83 and 68.21 µg g?1, respectively. The adsorption followed the pseudo 2nd order and well fitted the Langmuir isotherm. Mean recoveries ranging from 73% to 105.4% for both spiked deionized water and environmental water samples were obtained when the imprinted composites were employed in solid phase extraction of the PAHs. The composites could be re‐used for five times without a significant loss in recoveries. The proposed method was employed for the analysis of spiked environmental water samples and did not show significant changes in the recoveries showing there were no matrix interferences. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45300.  相似文献   

15.
Molecularly imprinted polymers are being proposed for the development of novel biorecognition elements for active components. In this study, an imprinted chitosan coated silica nanoparticles (I‐CS@SiO2) polymer was prepared by a simple procedure, in which, naringin (NG) with antioxidant activity, acted as a template, silica as a matrix and CS as a functional polymer. The binding properties were discussed by the equilibrium binding experiment method. Experiments show that the adsorption characteristics of I‐CS@SiO2 are better than that of nonimprinted polymer. It exhibited high selectivity for NG when compared with the nonimprinted polymer, with an imprinting factor α of 1.74. Scatchard analysis of the I‐CS@SiO2 indicated that there was a class of binding sites during the I‐CS@SiO2 recognizing NG: The dissociation constant of KD is 0.016 mmol L?1, the maximum apparent binding capacity of Bmax is 6.56 μmol g?1. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40491.  相似文献   

16.
Magnetic nanoparticles were attached to yeast by co‐precipitation reaction of FeCl3·6H2O and FeCl2·4H2O. Then, based on magnetite yeast composites (M@Y), the magnetic molecularly imprinted polymers (MMIPs) were synthesized for the selective recognition of beta‐cypermethrin (PP321). MMIPs were characterized by scanning electron microscopy, X‐ray diffraction, vibrating sample magnetometer, Fourier transform infrared analysis, thermogravimetric analysis, and elemental analysis. MMIPs exhibited uniform morphology and magnetic property (Ms = 17.87 emu/g) and thermal stability. Batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics, and selective recognition. The Langmuir isotherm model was fitted to the equilibrium data slightly better than the Freundlich model, and the adsorption capacity of MMIPs was 39.64 mg/g at 298 K. The kinetic properties of MMIPs were well described by the pseudo‐second‐order equation. Hydrogen bonds between methacrylic acid and PP321 were mainly responsible for the adsorption mechanism. The MMIPs prepared were applied to the separation of PP321 from experimental samples successfully. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

17.
Perfluorooctanoic acid (PFOA) contamination in the environment is a global problem. The aqueous phase is the main medium for PFOA because of its moderate solubility. Adsorption is a feasible way to remove PFOA because of its chemical and biological stability. In this study, a new type of molecularly imprinted polymer (MIP) for the selective adsorption of PFOA in aqueous solutions was synthesized by the precipitation polymerization method with PFOA as the template molecule after optimization. The adsorption kinetics and isotherms of the MIP adsorbent toward PFOA were studied, and the effects of the pH and cations on the adsorption were investigated with batch experiments. The results show that acrylamide (AAM) was the best functional monomer, and the optimal molar ratio of PFOA to AAM to ethylene glycol dimethacrylate (crosslinker) was 1:6:25. The optimized MIP adsorbent had a high affinity for PFOA, and the uptake percentage by the MIP adsorbent was 1.3–2.5 times that of the nonimprinted polymer (NIP) when PFOA existed alone. A maximum PFOA sorption capacity of 5.45 mg/g based on the Langmuir isotherm model was achieved with the MIP adsorbent. The MIP adsorbent exhibited a high selectivity for PFOA over competitive compounds (other perfluorinated alkyl carboxylic and sulfonic acids), whereas the NIP did not. Approximately 90% of the PFOA in the mixture was removed by the MIP adsorbent; this was 18 times that of the NIP. Moreover, the regenerability of the MIP adsorbent was confirmed in five sequential adsorption–desorption cycles without a significant reduction in the PFOA uptake. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43192.  相似文献   

18.
A novel molecular imprinting method for the preparation of molecularly imprinted poly(methacrylic acid)/silica hybrid composite materials (MIP‐HCMs) for the selective recognition of lincomycin (LIN) in aqueous media by prepolymerization and free‐radical copolymerization was investigated. In this study, methacrylic acid was selected as the functional monomer, methacryloxypropyltrimethoxysilane was used as the crosslinker, and tetraethoxysilane was used as the inorganic precursor. MIP‐HCM was characterized by FTIR spectroscopy, the Brunauer–Emmett–Teller method, and TGA. The selectivity of the sorbent was investigated by a batch competitive binding experiment with an aqueous LIN and clindamycin (CLI) mixture. The selectivity coefficient for LIN in the presence of CLI was 6.27, whereas the relative selectivity coefficient between LIN and CLI was 5.83. The absorption capability of MIP‐HCM and the selectivity coefficient were much higher than those of the nonimprinted blank polymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012  相似文献   

19.
Herein we report the electrosynthesis of polypyrrole with L ‐tryptophan (L ‐Trp) as a template to prepare molecularly imprinted polymers (MIPs). Overoxidized polypyrrole films with cavities complementary to the template were used for the enantioselective detection of L ‐Trp and D ‐tryptophan (D ‐Trp). Important parameters, such as the electropolymerization potential, overoxidization potential and time, thickness of the polypyrrole films, and scanning rate of the stripping voltammetric experiments, were varied to achieve an optimum sensor response. We found that L ‐Trp was inserted about 2 times higher into the imprinted polymer film than D ‐Trp. Also, in this study, an electrochemical quartz crystal microbalance technique was used to investigate the performance of overoxidized polypyrrole films. The enantioselectivity of the MIPs was attributed to the cavities in the imprinted films, which were complementary to the target molecules, both in shape and in positioning of the functional groups. The results also suggest the feasibility of preparing MIPs by electropolymerization for the enantioselective recognition of other amino acid enantiomers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

20.
A novel molecularly imprinted polymer (MIP) designed by molecular dynamics (MD) simulations was successfully prepared with norfloxacin as a template molecule, methyl acrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a crosslinker. According to the theoretical prediction and experimental preparation methods, three kinds of molecular imprinting materials were designed and synthesized with MD simulations and molecular imprinting technology. The best ratio of the template to the functional monomer to the crosslinker was 1:8:40 in these studies. The experimental results illustrate that the MD simulations were credible in compounding the components of the MIPs. The structure of the prepared polymers were characterized with various methods. To analyze the adsorption performances, many kinds of static adsorption tests, including kinetic, isotherm, and selectivity tests, were used. The results indicate that the novel adsorbents conformed to the pseudo–second‐order kinetic equation and followed the Langmuir isotherm model. The adsorption amounts of MIP2 at a ratio of 1:8:40 were about 29.35 mg/g at 298 K. The selective adsorption and reusable performance of norfloxacin were excellent. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42817.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号