Synthesis and characterization of molecularly imprinted polymer membrane for the removal of 2,4-dinitrophenol.

Molecularly imprinted polymers (MIPs) were prepared by bulk polymerization in acetonitrile using 2,4-dinitrophenol, acrylamide, ethylene glycol dimethacrylate, and benzoyl peroxide, as the template, functional monomer, cross-linker, and initiator, respectively. The MIP membrane was prepared by hybridization of MIP particles with cellulose acetate (CA) and polystyrene (PS) after being ground and sieved. The prepared MIP membrane was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters studied for the removal of 2,4-dinitrophenol included the effect of pH, sorption kinetics, and the selectivity of the MIP membrane. Maximum sorption of 2,4-nitrophenol by the fabricated CA membrane with MIP (CA-MIP) and the PS membrane with MIP (PS-MIP) was observed at pH 7.0 and pH 5.0, respectively. The sorption of 2,4-dinitrophenol by CA-MIP and PS-MIP followed a pseudo-second-order kinetic model. For a selectivity study, 2,4-dichlorophenol, 3-chlorophenol, and phenol were selected as potential interferences. The sorption capability of CA-MIP and PS-MIP towards 2,4-dinitrophenol was observed to be higher than that of 2,4-dichlorophenol, 3-chlorophenol, or phenol

Synthesis and characterization of a molecularly imprinted polymer for 2,4-Dinitrophenol uptake using 4-Vinylbenzoic acid as the complexing monomer.

A new technique for analysis of 2,4-dinitrophenol in water at low concentration is proposed based on a molecular imprinted polymer. Molecular imprinted polymer (MIP) is cross linked polymeric materials that exhibit high binding capacity and selectivity towards target molecules (template) purposely present during the synthesis process. The molecular imprinted polymer was prepared in bulk, radical polymerization method using 2,4-dinitrophenol, 4-vinylbenzoic acid, ethylene glycol dimethacrylate and benzoyl peroxide as template, functional monomer, cross-linker and initiator, respectively. Adsorption process for removal of nitrophenol by molecular imprinted polymer was evaluated under various conditions to determine the effect of pH, adsorption kinetics, the isotherm and its selectivity. The maximum adsorption of 2,4- dinitrophenol was 2.50 mg/g. The adsorption of 2,4-dinitrophenol by 4-vinylbenzoic acid was found most effective at pH 5.0. Kinetics study showed that 2,4-dinitrophenol adsorption was modeled by second order kinetic. Adsorption isotherm data could be interpreted using the Langmuir equation

Synthesis and characterization of molecularly imprinted polymer for removal of 2,4-dinitrophenol

In this work, molecular imprinted polymers (MIPs) were prepared by bulk polymerization method in acetonitrile using 2,4-dinitrophenol, acrylamide,ethylene glycol dimethacrylate, and benzoyl peroxide as template, functional monomer, cross-linker and initiator, respectively. The functional monomer and the cross linker (molar ratio of functional monomer to cross linker 1:3) and 1.6 mmol of the initiator BPO were used. Then, the polymer were crushed, ground and sieved to obtain regularly sized particles between 80-100 μm. The polymer obtained is then washed to remove the template using methanol/ acetic acid in 2:1 (v/v) ratio for 3 times. Membrane MIP was prepared by hybridization of MIP particle with cellulose acetate (CA) and polystyrene (PS), respectively. Sorption process for the removal of 2,4-dinitrophenol using the fabricated MIP was evaluated under various pH and time conditions. Parameters studied for the removal of 2,4-dinitrophenol include sorption kinetics, sorption isotherm, selectivity and reusability of the MIP and membrane MIP. The concentration of 2,4-dinitrophenol was analyzed using UV-Vis Spectrophotometer. The prepared MIP was characterized using Fourier transformed infrared (FTIR) spectroscopy,scanning electrode microscopy (SEM), thermo gravimetric analysis (TGA),particle size analyzer (PSA) and brunauer, emmett teller (BET) adsorption isotherm analysis. The FTIR spectra showed a broadening at 3400 cm-1 indicating that a hydrogen bond interaction takes place between the phenolic hydroxyl group and the carbonyl from the amide group. From the surface morphology of SEM image, MIP could be seen to exhibit a more porous and rough structure than MIP before extraction and NIP. The surface area of the MIP is 103.65 m2/g and the NIP is 8.99 m2/g. The results showed a type IV adsorptiondesorption isotherm, which is typically characteristic of mesoporous materials. The size of the MIP particles was in the range of 130.00 nm and the particles size of non imprinted polymer (NIP) was in the range 400.00 nm. The maximum sorption of 2,4-dinitrophenol by MIP was found to be 2.88 mg/g under acidic conditions at pH 6.0. The maximum sorption of 2,4-nitrophenol by the fabricated cellulose acetate membrane with molecular imprinted polymer (CA-MIP) and polystyrene membrane with molecular imprinted polymer (PS-MIP) were found at pH 7.0 and pH 5.0, respectively. Sorption data for MIP, CA-MIP and PS-MIP were described well at the Langmuir isotherm model equilibrium. The sorption of MIP, CA-MIP and PS-MIP towards 2,4-DNP reaches equilibrium in 1 h and 2 h , respectively. The sorption of the 2,4-DNP by the MIP, CA-MIP and PS-MIP were found a better model at pseudo-second-order kinetic equation compared to first-order equation. For selectivity study, 2,4-dichlorphenol (2,4-DCP), 3-chlorophenol (3-CP) and phenol were selected as potential interferences. The sorption abilities of MIP, CA-MIP and PS-MIP for 2,4-DNP were far stronger than that of 2,4-DCP, 3-CP and phenol. The MIP could be reused after extraction with methanol: acetic acid in 2:1 (v/v) ratio and was stable for up to five sorption cycles without obvious decrease in the sorption capacity for 2,4- DNP

Synthesis and Evaluation of a Molecularly Imprinted Polymer for 2,4-Dinitrophenol

Molecular imprinted polymers (MIP) are considered one of the most promising selective and novel separation methods for removal phenolic compound in wastewater treatment. MIP are crosslinked polymeric materials that exhibit high binding capacity and selectivity towards a target molecule (template), purposely present during the synthesis process. In this work MIP were prepared in a bulk polymerization method in acetonitrile using 2,4-dinitrophenol, acrylamide, ethylene glycol dimethacrylate, and benzoyl peroxide as template, functional monomer, cross-linker and initiator, respectively. An adsorption process for removal of nitrophenol using the fabricated MIP was evaluated under various pH and time conditions. The parameters studied for 2,4-dinitrophenol includes adsorption kinetics, adsorption isotherm, and selectivity. The maximum adsorption of nitrophenol by the fabricated MIP was 3.50 mg/g. The adsorption of 2,4-dinitrophenol by the fabricated MIP was found effective at pH 6.0. A kinetics study showed that nitrophenol adsorption follows a second order adsorption rate and the adsorption isotherm data is explained well by the Langmuir model