Preparation and Evaluation of Water-Compatible Surface Molecularly Imprinted Polymers for Selective Adsorption of Bisphenol A from Aqueous Solution

J of Applied Polymer Sci

et al. 2015

Self Cite

Thermoresponsive hollow magnetic microspheres consisting of a hollow magnetic core, a carbon shell, and a smart polymer layer are presented in this article. A carbon nanomaterial was used as a steric stabilizer for Fe 3 O 4 nanoparticles and a supporter for polymer. The thermoresponsive monomer, N-isopropyl acrylamide, was grafted on the carbon-encapsulate hollows by surface radical polymerization. The experimental results indicate that the composites had a phase-transition temperature around 438C and a saturation magnetization of 56.9 emu/g; this showed apparent thermosensitivity and magnetism. The performances in hyperthermia evaluated by an inductive magnetic field showed that the hybrid microspheres had a specific absorption rate of 240 W/g. The model drug, 5-fluorouracil, was loaded in and released from the microspheres with different release rates at 35 and 508C. This demonstrated that the as-synthesized microspheres had a thermotriggered release ability and would be a good drug carrier in the biomedical field.

Section: Resultssupporting

confidence: 73%

Thermoresponsive hollow magnetic microspheres with hyperthermia and controlled release properties

Chen

J of Applied Polymer Sci

et al. 2015

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“…To further study the mechanism of the recognition process of TMMIPs for 5‐FU, pseudo‐first‐order equation and pseudo‐second‐order equation were applied to analyze the adsorption data …”

Section: Resultsmentioning

confidence: 99%

“…The pseudo‐first‐order equation is described as:

\ln (Q_{e} - Q_{t}) = \ln Q_{e} - k_{1} t

where Q e and Q t are the adsorbed 5‐FU amounts on TMMIPs at equilibrium and at times t (mg/g), respectively, and k 1 is the rate constant of the pseudo‐first‐order equation adsorption (1/min), which can be obtained from the linear plot of ln( Q e − Q t ) versus t .…”

Section: Resultsmentioning

confidence: 99%

“…The pseudo‐second‐order equation comprises all the steps of adsorption including external diffusion, adsorption, and internal particle diffusion, which is described as:

t / Q_{t} = 1 / k_{2} Q_{e}^{2} + t / Q_{e}

where Q e and Q t are defined the same as in the pseudo‐first‐order equation and k 2 [g/(mg min)] is the rate constant of the pseudo‐second order equation, which can be obtained from the linear plot of t / Q t versus t .…”

Section: Resultsmentioning

confidence: 99%

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Recognition of 5‐fluorouracil by thermosensitive magnetic surface molecularly imprinted microspheres designed using a computational approach

Chen

J of Applied Polymer Sci

et al. 2017

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Thermosensitive magnetic surface molecularly imprinted polymer microspheres based on thermosensitive monomer n‐isopropylacrylamide (NIPAM) are applied for the recognition of 5‐fluorouracil (5‐FU). A computational analysis is used to predict the interaction sites between 5‐FU and NIPAM, the stoichiometry of the synthesis procedure, and the affinity of imprinted cavities toward 5‐FU. Due to hydrogen bond interactions, a stable complex configuration of 5‐FU and NIPAM shows a binding energy of −46.50 kJ/mol confirming the suitability of imprinting 5‐FU into thermosensitive polymer network. After optimization, the appropriate stoichiometry of 5‐FU to NIPAM is set to 1:4 during the preparation process. The simulated imprinted cavities show affinity toward 5‐FU, with a binding energy of −112.24 kJ/mol. A preliminary experimental evaluation for the drug recognition of thermosensitive magnetic surface molecularly imprinted polymer microspheres is made, obtaining an adsorption capacity of 21.72 mg/g at 25 °C. Pseudo‐second‐order kinetics well describes the adsorption process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45468.

“…The standard Gibbs free‐energy change Δ G ° (kJ/mol), the standard enthalpy change Δ H °(kJ/mol), and the standard entropy change Δ S ° (J/mol·K) can be calculated from the adsorption isotherms to provide in‐depth information about internal energy changes about adsorption. The Δ G °, Δ H °, and Δ S ° are calculated from the following equations :

Δ G^{0} = - R T l n K^{0}

l n K^{0} = \frac{Δ S^{0}}{R} - \frac{Δ H^{0}}{R T}

K_{d} = \frac{C_{0} - C_{normale}}{C_{e}} * \frac{V}{m}

where K ° is the adsorption equilibrium constant, which can be calculated by plotting ln K d versus C e and the value of the intercept is that of ln K °, K d is the adsorption distribution coefficient, C 0 is the initial concentration (μg/mL), C e is the equilibration concentration of E1 in solution (μg/mL), V is the volume of the solution (mL), and m is the mass of the EMIPs or ENIPs (mg), R is the universal gas constant (8.314 J/K·mol) and T is the temperature in absolute temperature.…”

Section: Resultsmentioning

confidence: 99%

Facile preparation of polydopamine‐coated imprinted polymers on the surface of SiO₂ for estrone capture in milk samples

Zheng

J of Separation Science

Luo

et al. 2016

Estrone molecularly imprinted polymers were synthesized through the self-polymerization of dopamine on the surface of silica gels, which had the characteristics of mild polymerization conditions, simple reaction procedure and good specific recognition ability for estrone. The estrone molecularly imprinted polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and nitrogen adsorption-desorption tests. The characterization confirmed that the imprinted polymers were successfully grafted on the surface of silica gels. Through investigating the adsorption performance, the prepared estrone molecularly imprinted polymers exhibited high adsorption capacity, fast mass transfer, as well as excellent selectivity toward estrone. The estrone molecularly imprinted polymers as the solid-phase extraction adsorbent coupled with high-performance liquid chromatography was developed to determine estrone from the milk samples. The developed estrone molecularly imprinted polymer solid-phase extraction with high-performance liquid chromatography method exhibited satisfactory specificity, precision, accuracy and good linearity relationship in the range of 0.2-20 μg/mL. The developed method is simple, fast, effective and high specificity method and it provides a new method to detect the residues of estrone in animal foods.