Precipitation Polymerization Method Research Articles

Synthesis of reactive polyamide porous materials and introduction of crosslinking

ABSTRACT Porous crosslinked aromatic polyamides were prepared in a single-step process by reacting a triacid chloride monomer with a diamine monomer having COOH groups via a precipitation polymerization method. The resulting materials were agglomerates of polyamide particles having COCl and COOH groups with average diameters of 30–70 nm and average pore diameters in the range of ca. 20–40 nm. The concentration of COCl groups and the porous structure were significantly affected by the monomer ratio, the total monomer concentration and the reaction solvent. These COCl groups were subsequently modified by reaction with 1,8-diaminooctane in three different solvents, and the extent of modification depended strongly on the solvent. This modification produced aromatic polyamides having two types of crosslinking, based on of the 1,8-diaminooctane and the aromatic polyamide product, which were cleaved in different temperature ranges. The COCl groups introduced were found to have high reactivity and react with NH2 groups even in water, prior to hydrolysis.

Preparation and optimization of dummy molecularly imprinted polymer-based solid-phase extraction system for selective enrichment of p-toluene sulfonate esters genotoxic impurities

Sulfonate esters, one class of genotoxic impurities (GTIs), have gained significant attention in recent years due to their potential to cause genetic mutations and cancer. In the current study, we employed the dummy template molecular imprinting technology with a dummy template molecule replacing the target molecule to establish a pretreatment method for samples containing p-toluene sulfonate esters. Through computer simulation and ultraviolet–visible spectroscopy analysis, the optimal functional monomer acrylamide and polymerization solvent chloroform were selected. Subsequently, a dummy template molecularly imprinted polymer (DMIP) was prepared by the precipitation polymerization method, and the polymer was characterized in morphology, particle size, and composition. The results of the adsorption and enrichment study demonstrated that the DMIP has high adsorption capability (Q = 7.88 mg/g) and favorable imprinting effects (IF = 1.37); Further, it could simultaneously adsorb three p-toluene sulfonate esters. The optimal adsorption conditions were obtained by conditional optimization of solid-phase extraction (SPE). A pH 7 solution was selected as the loading condition, the methanol/1% phosphoric acid solution (20:80, v/v) was selected as the washing solution, and acetonitrile containing 10% acetic acid in 6 mL was selected as the elution solvent. Finally, we determined methyl p-toluene sulfonate alkyl esters, ethyl p-toluene sulfonate alkyl esters, and isopropyl p-toluene sulfonate alkyl esters in tosufloxacin toluene sulfonate and capecitabine at the 10ppm level (relative to 1 mg/mL active pharmaceutical ingredient (API) samples) by using DMIP-based SPE coupled with HPLC. This approach facilitated the selective enrichment of p-toluene sulfonate esters GTIs from complex API samples.

An ultra-selective and non-enzymatic colorimetric sensor based on imprinted polymer for ephedrine assay in urine samples

A novel non-enzymatic, rapid, and portable molecularly imprinted polymer (MIP)-based colorimetric sensor was developed for ephedrine (EPD) assay in urine samples. The EPD-imprinted polymer was provided via the precipitation polymerization method and applied to fabricate an EPD colorimetric sensor utilizing the carbon disulfide and Cu2+ reagents. The calibration curve for different concentrations of EPD was obtained using the captured images on a cell smartphone and associated RGB data. Some effective parameters including pH of the EPD extraction, time of data collection after adding the reagents, and reagents sequence were investigated and optimized. The selectivity of the sensor was studied using different similar structural compounds, which proved the favorable capability of this method for the selective determination of EPD. This sensor platform with a relatively wide linear calibration range (1-100μM), and the detection limit of 0.6μM represents the efficient, reliable, and easy approach for EPD assay in urine samples.

Silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) microgels: Extraction of palladium (II) ions and in situ formation of palladium nanoparticles for pollutant reduction

Most of the transition metal ions and organic dyes are toxic in nature. Therefore, their removal from water is imperative for human health. For this purpose, various types of systems have been developed to tackle either transition metal ions or organic dyes individually. A core-shell microgel system is introduced which is capable of effectively removing both types (toxic organic dyes and transition metal ions) of pollutants. A long-rod-shaped silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) S@P(CS-NIPAM-MAA) S@P(CNM) core-shell microgel system was developed by free radical precipitation polymerization method (FRPPM). S@P(CNM) was utilized as an adsorbent for extracting palladium (II) (Pd (II)) ions from water under different concentrations of S@P(CNM), several agitation times, palladium (II) ion content, and pH levels. The adsorption data of Pd (II) ions on S@P(CNM) was evaluated by various adsorption isotherms. The kinetic study was investigated by employing pseudo-2nd order (Ps2O), Elovich model (ElM), intra-particle diffusion (IPDM), and pseudo-1st order (Ps1O). Additionally, palladium nanoparticles (Pd NPs) were generated via in-situ reduction of adsorbed Pd (II) ions within the P(CNM) shell region of S@P(CNM). The resulting Pd NPs loaded S@P(CNM) exhibited the capability to reduce organic pollutants like methyl orange (MeO), 4-nitrophenol (4NiP), methylene blue (MeB), and Rhodamine B (RhB) from aqueous medium. 0.766 min−1, 0.433 min−1, 0.682 min−1, and 1.140 min−1 were the values of pseudo 1st order rate constant (kobs) for catalytic reduction of MeB, 4NiP, MeO, and RhB respectively. The S@Pd-P(CNM) system exhibits significant catalytic potential for various organic transformations.

Preparation of molecularly imprinted polymer for the specific adsorption and selective extraction of alkylresorcinols from whole wheat flour

Alkylresorcinols are important biomarkers for evaluating whole wheat foods. However, their structures encompass a broad spectrum of homologs, making isolating and analyzing individual alkylresorcinols notably challenging. Herein, we synthesized highly selective molecularly imprinted polymers (MIPs) utilizing a facile and cost-effective precipitation polymerization method and 5-heneicosylresorcinol (ARC21:0) as the template molecule. Various crucial preparation parameters were systematically optimized, such as different porogens, functional monomers, imprinting ratios, and polymerization time. The polymers were characterized through scanning electron microscopy and Fourier transform infrared spectroscopy, and their adsorption performances were thoroughly evaluated. MIPs exhibited a notably enhanced adsorption capacity compared with that of non-imprinted polymers, reaching an optimal adsorption amount of 71.75 mg·mL−1 and imprinting factor of 2.02. Altogether, the synthesized MIPs showed superior affinity and selectivity for ARC21:0, as confirmed by their selective extraction, suggesting their potential applications in the analysis, separation, and monitoring of ARC21:0 in whole wheat foods.

A sensitive enzyme-free electrochemical sensor based on ZnWO4/γ-Fe2O3 magnetic molecularly imprinted polymer for specific recognition and determination of Chloramphenicol

A chloramphenicol (CAP) electrochemical sensor based on zinc tungstate and magnetic hematite (ZnWO4/γ-Fe2O3) magnetic molecularly imprinted polymer (ZnWO4/γ-Fe2O3/MIP) is proposed. First, ZnWO4, γ-Fe2O3 nanomaterials were synthesized by one-step hydrothermal method, and then ZnWO4, magnetic nanoparticles were combined with molecularly imprinted polymers, that is, ZnWO4/γ-Fe2O3 was coated with a molecularly imprinted (MIP) shells by precipitation polymerization method to prepare magnetic molecularly imprinted nanomaterials, and then modified on glassy carbon electrodes to construct an electrochemical sensor for the determining of CAP. The results show that under the optimal conditions, the ZnWO4/γ-Fe2O3/MIP (MMIP) modified electrode has a stronger CAP detection reduction peak current than the one-component electrode, and exhibits better electrocatalytic activity, which is an excellent electrochemically modified electrode. Compared to magnetic non-molecular imprint sensors (MNIP), MMIP sensors have higher detection efficiency. The linear range of ZnWO4/γ-Fe2O3/MIP/GCE for the detection of CAP was 0.12 ∼ 1224 μM, and the detection limit was 0.034 μM, showing excellent stability and reproducibility, and good selectivity in the presence of different interferences. ZnWO4/γ-Fe2O3/MIP/GCE was applied to the detection of CAP in milk samples with satisfactory results.

Facile construction of a stable core-shell spherically magnetic polyimide covalent organic framework for efficient extraction of phenylurea herbicides

Efficient enrichment is crucial for the highly sensitive monitoring of phenylurea herbicides (PUHs) in various environmental waters. In this work, a stable core-shell spherically magnetic polyimide covalent organic framework (COF) was synthesized via a simple template-mediated precipitation polymerization method under mild conditions using tri(4-aminophenyl)amine (TAPA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) as the building units (denoted as Fe3O4@TAPA-BPDA). The Fe3O4@TAPA-BPDA exhibits remarkable adsorption performance for PUHs with an optimized adsorption time of only 10 min. The adsorption of PUHs by Fe3O4@TAPA-BPDA followed the pseudo-second-order kinetic model and the Langmuir model. Furthermore, hydrogen bonding, halogen bonding, hydrophobic interaction, electro donor-acceptor interaction and π-π interactions are identified as the dominant mechanisms contributing to excellent adsorption performance. It was demonstrated that halogen bonds play an important role in the adsorption of substances containing chlorine atoms. The Fe3O4@TAPA-BPDA is easy to operate and highly regenerable. A simple magnetic solid-phase extraction (MSPE) method based on the Fe3O4@TAPA-BPDA was then developed for the rapid extraction of five PUHs in real samples, coupled with high-performance liquid chromatography (HPLC) determination. The analytical method developed has a linear range of 0.5–50 ng/mL, and the limit of detection (LOD) ranges from 0.06 to 0.10 ng/mL. The method exhibits good accuracy with recoveries ranged from 74.5 % to 111.4 %. The analytical method was successfully applied to the highly sensitive detection of PUHs in environmental water samples, which highlighting the potential application of the Fe3O4@TAPA-BPDA in the sample pretreatment.

Monolayer of microgel particles based on poly(acrylic acid) modified with dopamine for electrochemical pH sensing

A novel electroactive and pH-responsive microgel was successfully synthesized. The obtained microgel was based on acrylic acid, dopamine methacrylamide and N,N′-bis(acryloyl)cystamine as the crosslinker. Using the distillation precipitation polymerization method, spherical, smooth-surface microgel particles of ca. 400 nm in diameter were obtained. The presence of dopamine groups in the polymer network was confirmed with cyclic voltammetry and NMR spectroscopy. The dependence of microgel hydrodynamic diameter on pH was investigated using the DLS technique. The presence of -S–S- groups in the microgel particle was used to modify the Au electrode surface by chemisorption. The attachment was monitored with the QCM-D technique. The obtained microgel was successfully anchored to the Au regular- and microelectrode surfaces. The electrochemical properties of the modified electrodes were promising. It was found that modified electrodes exhibited potentially useful pH-sensing properties. Modification of Au microelectrode surface with the environmentally sensitive and electroactive microgel monolayer is a novel, innovative approach.

Temperature/pH/reduction-sensitive multiple stimulus-responsive nanogels synthesized by one-pot method for design as curcumin carriers

Curcumin (Cur) is of interest due to its widely reported pharmacology, which is limited by its low water solubility and low bioavailability of clinical use. Here, we report the characterization and application of a multiple stimulus-responsive nanogel loaded with Cur. Sensitive P(AM-co-NIPAM) nanogels for pH, temperature, and reduction stimuli were prepared by reflux precipitation polymerization method using AM and NIPAM as raw materials. DLS and SEM analyses showed that the fabricated nanogels had a uniform size distribution with spherical and nucleated-shell structures. By adjusting the feeding amounts of reactive monomers, cross-linkers, and initiators, a series of monodisperse nanogels with different particle sizes could be obtained. The representative nanogels have different Cur-loaded behaviors at different temperatures, times, and initial concentrations of the drug, as well as a sensitive release to changes in pH, temperature, or reducing conditions. Cur-P(AM-co-NIPAM) nanogels showed superior antioxidant activity over the free Cur in vitro. Meanwhile, it inhibited LPS and H2O2-induced oxidative stress, which could effectively inhibit the cellular production of excessive reactive oxygen species and had a protective effect against LPS-induced cellular damage. This nanogel controlled release system significantly improved the safety limit of Cur without hemolytic behavior and had good cytocompatibility. The successful development of such Cur nanogels will lead to advanced materials that can be functionalized and optimized for the controlled delivery of small molecules or biomolecules for targeted therapeutic and biomedical applications.

Determination of atropine and scopolamine in honey using a miniaturized polymer-based solid-phase extraction protocol prior to the analysis by HPLC-MS/MS

Two homopolymers have been prepared employing methacrylic acid and 4-vynylpiridine as functional monomers (p-MAA, p-4-VP) through an easy and quick precipitation polymerization method for application as sorbents in solid-phase extraction (SPE) to determine atropine and scopolamine in honey. The optimized SPE conditions were as follows: 25 mg of p-MAA, 4 mL of sample loading volume (diluted honey 1:10 with water), 4 mL of elution solvent (methanol/water with 1 % formic acid, 80/20, v/v). The extracts were analyzed by HPLC-MS/MS. The cartridges were reusable for forty cycles demonstrating an environmentally friendly approach. The methodology was validated in terms of linearity, accuracy, precision, selectivity, matrix effect and sensibility, highlighting the absence of matrix effect. The miniaturized polymer-based SPE was successfully applied to fifteen honeys, showing concentrations up to 7.23 ng/g in the most contaminated honey. All quantified honey samples (5 in total) were of multifloral type.

Development of an Optical Sensor Using a Molecularly Imprinted Polymer as a Selective Extracting Agent for the Direct Quantification of Tartrazine in Real Water Samples.

This study presents a new optical sensor for tartrazine (TAR) quantification developed using a molecularly imprinted polymer (MIP) as the recognition element, with optical fiber serving as the supporting substrate. The fiber surface was functionalized with 3-(trimethoxysilyl)propyl methacrylate (MPS), and the fiber was coated with MIP using the precipitation polymerization method. The analysis of MIP immobilization on the functionalized optical fiber (FF) was conducted through the use of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Experimental parameters, such as contact time and fiber length, were adjusted in order to obtain the highest sensitive response signal for the functionalized optical fiber (FF-MIP). The fiber sensor, FF-MIP, exhibited a relatively higher response signal for tartrazine compared to other interfering dyes. The rapid and total desorption of the analyte from FF-MIP allowed the immediate reemployment of FF-MIP, which also presented an acceptable repeatability for the reflectance signal. The imprinting factors for the studied dyes were between 0.112 and 0.936 in front of TAR, 1.405, and selectivity factors were between 1.501 and 12.545, confirming the sensor selectivity. The FF-MIP sensor was successfully applied for tartrazine quantification in real water samples, where it yielded satisfactory results comparable to those of the HPLC reference method.

Improvement of the selectivity of a molecularly imprinted polymer-based potentiometric sensor by using a specific functional monomer

Potentiometric sensors based on the molecularly imprinted polymers (MIPs) as the receptors have been successfully developed for determination of various organic and biological species. However, these MIP receptors may suffer from problems of low selectivity. Especially, it would be difficult to distinguish the target analyte from its structurally similar interferents. In this work, we propose a novel strategy that using specific functional monomer to fabricate MIP with high selectivity towards the target molecule. The density functional theory calculations are used to investigate the interactions between the template and the functional monomer. The binding energy between the template and functional monomer can be used as the criterion for identifying the optimal monomer. As a proof-of-concept experiment, bisphenol A (BPA) is chosen as the template and the MIP is synthesized by the precipitation polymerization method using the specific allyl-β-cyclodextrin (allyl-β-CD) with high affinity towards BPA as the functional monomer. The high-affinity MIP is employed as the receptor for the construction of the potentiometric sensor. The proposed potentiometric sensor based on the MIP using allyl-β-CD as the functional monomer shows an improved response performance in terms of selectivity and sensitivity compared to the conventional potentiometric sensor based on the MIP with the common monomer (i.e., methacrylic acid). This allyl-β-CD MIP-based potentiometric sensor shows a detection limit of 0.29 μM for BPA, which is about one order of magnitude lower than that obtained by the conventional MIP-based potentiometric sensor. We believe that utilizing a functional monomer with specific recognition ability towards target in the fabrication of MIP could provide an appealing way to construct highly selective MIP-based electrochemical and optical sensors.

Facile and fast fabrication of magnetic molecularly imprinted polymer for extraction of carbamazepine from environmental samples and fish tissues followed by UHPLC-MS/MS detection

A rapid synthesis of carbamazepine (CBZ) magnetic molecularly imprinted polymer (MMIP) was proposed based on reflux precipitation polymerization method. The synthesis time for the formation of MIP coating on MMIP was shortened to less than 4 h. The characterization of MMIP demonstrates the successful synthesis of the imprinted layer. The adsorption selectivity of MMIP was systematically evaluated and showed fast selective recognition for CBZ. The MMIP based magnetic solid-phase extraction (MSPE) combined with UHPLC-MS/MS was developed, and its feasibility was validated in four complex matrices of environmental water, sediment, fish muscle and liver. It was successfully applied for the analysis of environmental water, sediment, and different fish tissues. Four environmental water samples from different sampling sites were found to contain CBZ at concentrations < LOD or LOQ, while the sediment samples collected at the same location did not contain CBZ. Two out of three wild snakeheads were found to contain CBZ, and the liver showed the highest residue. The study of drug exposed snakeheads indicate CBZ tends to accumulate in liver, followed by brain, heart and kidneys, and finally muscle and gills. The proposed method displays high potential for analyzing CBZ in complex environmental and biological samples.

Computational simulation-assisted design and experimental verification of molecularly imprinted polymers for selective extraction of chlorogenic acid

Chlorogenic acid (CGA) is an active ingredient in honeysuckle with a broad-spectrum of antibacterial activity, suppressing tumor growth and other pharmacological effects. However, it is susceptible to damage during traditional extraction and separation processes. Therefore, developing selective and efficient extraction methods of CGA is essential. Based on computational molecular simulations, a reliable and efficient molecularly imprinted polymers (MIPs) were successfully developed for selective extraction of CGA. MIPs and non-molecularly imprinted polymers (NIPs) were synthesized using a precipitation polymerization method, employing three different functional monomers: [methacrylic acid (MAA), 4-vinylpyridine (4-VP), and methyl methacrylate (MMA)], with CGA serving as the template molecule. To simulate the polymers and predict the optimal ratio between the template and functional monomer, the computational studies and adsorption performance experiments were carried out. The adsorption characteristics and thermal stability of polymers were evaluated by isothermal adsorption, adsorption kinetics, selective adsorption and thermogravimetric analysis, aiming to obtain the MIPs with specific recognition and selectivity for CGA. When the molar ratio of template CGA to functional monomer 4-VP was 1:8, the prepared MIPs was found to have the maximum adsorption capacity (14.85 mg g−1) and the highest imprinting factor (1.74) at the CGA concentration of 100 mg L−1. These results were consistent with those obtained by computational molecular simulation. This study not only provides good guidance for developing separation materials for extracting CGA from natural plants but also inspires the application of computer simulation and molecular docking techniques in the preparation of specific MIPs materials.

Synthesis and Evaluation of Molecularly Imprinted Nanoparticles for Detection and Quantification of Zolpidem In Human Plasma

AbstractIn response to the alarming rates of zolpidem abuse, this study presents a pioneering approach utilizing molecularly imprinted nanoparticles (MIPs) in conjunction with high‐performance liquid chromatography (HPLC) for the selective detection of zolpidem. The rational choice of zolpidem as the target analyte stems from its widespread misuse and clinical significance. The MIPs were prepared using the precipitation polymerization method, resulting in monodispersed nanoparticles with a size of approximately 258.8 nm. Fourier Transform Infrared (FTIR) analysis confirmed the successful incorporation of zolpidem into the MIPs, designed with tailored cavities for zolpidem recognition. Moreover, incorporating the bathochromic shift phenomenon reaffirms the successful imprinting procedure. The rebinding studies showed that MIPs were highly efficient in adsorbing zolpidem from the solvent, with more than 95 % of the drug recovered after multiple cycles. The selectivity study demonstrated the MIPs′ preference for zolpidem over another drug, diazepam. The MIPs′ successful separation of zolpidem from spiked human plasma samples further validates their potential for practical applications, such as clinical toxicology. This research showcases the potential of MIPs coupled with HPLC as a powerful tool for accurate zolpidem quantification, holding great promise for combating drug abuse and advancing analytical methodologies for pharmaceutical analysis.

Copper (II) ions extraction by poly(N-vinylcaprolactam-mathacrylic acid) microgels for in situ reduction formation of copper nanoparticles to reduce pollutants

It is very important to eliminate organic dyes and most of the toxic transition metal ions from water because they are hazardous substances for livings. Many systems are reported to eliminate organic pollutants or transition metal ions solely from water. A new systematic way has been developed for effectively removal of both metal ions and organic pollutants (nitroarenes and toxic dyes). For this purpose, a spherical poly(N-vinylcaprolactam-co-methacrylic acid) P(NVC-MAAc) microgel system was developed by free radical precipitation polymerization (FRPP) method. The XRD, FTIR, SEM, DLS, and TEM techniques were used for characterization of P(NVC-MAAc) system and then used that system as an adsorbent for removal of copper (II) ions from water under a variety of conditions, including different P(NVC-MAAc) concentrations, pH, copper (II) ions contents, and agitation times. Various adsorption isotherms were applied to evaluate the best fitted adsorption isotherms for extraction of copper (II) ions with P(NVC-MAAc) microgel system. Furthermore, the kinetics of copper (II) ion adsorption on P(NVC-MAAc) were investigated using the pseudo-1st order (P1O), intra-particle diffusion model (InPDM), pseudo-2nd order (P2O), and Elovich model (EM). The loaded copper (II) ions in P(NVC-MAAc) microgel were then in-situ reduced to generate copper nanoparticles (NPs). The resulted [Cu-P(NVC-AAc)] hybrid microgels were used as catalyst to reduce toxic pollutants from water such as 4-nitrophenol (4NiP), 4-nitroaniline (4NiA), chromium (VI) ions (ChVI), rhodamine-B (RhB), methyl orange (MeO), and eyosin-Y (EyY). The values of apparent rate constant (kapp) for 4NiP, 4NiA, ChVI, RhB, MeO and EyY were found 0.725 min−1, 0.587 min−1, 0.097 min−1, 0.821 min−1, 0.860 min−1, and 0.833 min−1 respectively. As a result, a broad range of new organic transformations can be efficiently catalyzed by the Cu-P(NVC-MAAc) system.

Synthesis of molecularly imprinted polymer for the removal of cyanazine from aqueous samples

BackgroundCyanazine (CYZ) is one of the triazine herbicides to prevent broadleaf grass and weeds in crops. Despite its affordability and productivity in increasing crop yield, the extensive usage of CYZ contributes to environmental pollution and poses risks to living organisms. Most research has focused on detecting CYZ in the environment and its toxicity to humans and the ecosystem. For these reasons, molecular imprinting technology (MIT) can be applied to produce an effective adsorbent material of high binding affinity and selectivity towards its target compound which is known as molecularly imprinted polymers (MIPs). In this study, MIP was prepared by precipitation polymerization using CYZ as a template molecule, methacrylic acid (MAA), acrylamide (AAm) and 4-vinylpyridine (4VP) as functional monomers, and ethylene glycol dimethacrylate (EGDMA) as cross-linker in the ratio of 1:6:12, respectively. The effects of contact time, initial concentration, pH, and polymer dosages on the adsorption efficiencies of MIPs were also investigated in this study.ResultsMIPs of CYZ were successfully synthesized by precipitation polymerization method with a non-covalent approach using different functional monomers such as methacrylic acid (MAA), acrylamide (AAm) and 4-vinylpyridine (4VP). For the comparison study, the non-imprinted polymer (NIP) was synthesized without the addition of CYZ, the template molecule. The FTIR analysis indicated the interactions among CYZ and functional monomers (MAA, AAm or 4VP) in the presence of EGDMA as a cross-linker. The FESEM analysis showed that only MIP (AAm) and NIP (AAm) had regular and spherical polymer particles while MIP (MAA), NIP (MAA), MIP (4VP) and NIP (4VP) were agglomerated and irregular in shape. The EDX analysis showed that the MIPs were mainly composed of carbon and oxygen. Meanwhile, the BET analysis of MIP (AAm) had higher surface area, total pore volume and average pore radius than that NIP (AAm). Based on the batch binding study, MIP (AAm) (83.30%) had the highest binding efficiency than the MIP (MAA) (76.96%) and MIP (2VP) (76.90%) at a contact time of 240 min. The optimum conditions for the highest binding efficiency of MIP (AAm) were obtained at an initial concentration of 6 ppm, pH 7 and polymer dosage of 0.1 g polymer beads. The adsorption efficiency of MIP (AAm) with CYZ at the optimum parameters resulted in 86.39%. The selectivity test showed that MIP (AAm) was more selective towards CYZ than AME, the competitive compound with relative selectivity coefficient of 2.36. The kinetic isotherm of MIP (AAm) was best explained according to the pseudo-second-order kinetic model while the adsorption isotherm of MIP (AAm) was based on the Langmuir adsorption isotherm model. The MIP (AAm) was tested in the distilled water (DIW), tap water and river water spiked with CYZ and a substantial amount of CYZ was removed with a recovery of 86.67%, 84.75% and 84.69%, respectively.ConclusionThe MIPs of CYZ were successfully synthesized by the precipitation polymerization method using different functional monomers. Among those MIPs, MIP (AAm) showed the highest rebinding efficiency and therefore this MIP was selected for further studies. The best combination of CYZ, AAm was the main factor that contributed to the morphological and chemical properties, as well as the efficiency and selective binding performance of MIP (AAm). Since MIP (AAm) showed a substantial removal efficiency of CYZ in the environment specifically water sources, it has the capability to act as an adsorbent material for various purposes such as solid-phase extraction techniques and a stationary phase in various chromatographic techniques.Graphical

A novel dynamic coating medium for single stranded DNA separation in capillary electrophoresis: Thermosensitive hydrogel nanoparticles

Nowadays, research on single-stranded DNA (ssDNA) requires a quick, effective and easy operation method to separate small ssDNA fragments from the organism and ssDNA production process to realize their application in gene therapy and drug diagnosis. Herein, a novel separation matrix of thermosensitive hydrogel nanoparticles (NPs) was proposed, which has been successfully applied to the isolation of biomacromolecules such as enzymes, peptides and proteins, based on the desirable properties of various monomers and advantages, such as high sieving capacity, tunability of hydrophilic and hydrophobic performance and non-toxicity. The flexible particles were prepared by precipitation polymerization method in aqueous solution while N-isopropylacrylamide (NIPAm), acrylic acid (AAc) and N-t-butyl acrylamide (TBAm) was performed as co-monomer, which were first used as the dynamic coating to separate small fragments of ssDNA in capillary electrophoresis (CE). The synthesized NPs were bound to the inner wall of the capillary through non-covalent interactions forming stable dynamic coating to affect the electroosmotic flow and improve the separation reproducibility of ssDNA fragments. Based on the formulation design of NPs and condition optimization of electrophoresis, the running buffer TG (25 mM Tris, 192 mM glycine, pH 8.3) was modified by 4 mg·mL−1 optimized NPs aqueous suspension addition while its molar feed ratio of NIPAm /AAc /TBAm /BIS was 83/5/10/2 and particle size was about 214 nm. Both the formulation design and temperature sensitivity of hydrogel nanoparticles contributed to the DNA separation efficiency. The designed NPs with low viscosity provide an approach to increase their capability as the separation medium for small fragment DNA with important physiological functions great potential and promise.

Pharmacokinetic study and the extraction efficiency of bulk and precipitated ibuprofen-imprinted polymer sorbents for gas chromatography and gas chromatography-mass spectrometry ibuprofen bio-analysis.

Bulk and precipitation polymerization methods were used to prepare ibuprofen-molecularly imprinted polymers. Molecularly imprinted polymer-bulk and -precipitation were synthesized in acetonitrile, likewise molecularly imprinted polymer-bulk (mixture) and molecularly imprinted polymer-precipitation (mixture) in a mixture of acetonitrile/toluene (75:25 v/v). N2 adsorption-desorption analysis data revealed that molecularly imprinted polymer-precipitation (mixture) has the highest specific surface area (200.74 m2 g-1 ). The surface chemistry and morphology of the synthesized sorbents were investigated by Fourier-transform infrared analysis and scanning electron microscope micrographs respectively. The prepared sorbents in the mixture of solvents were used in a dispersive solid-phase extraction process for selective extraction and pre-concentration of ibuprofen from urine and human plasma samples. The detection limits were 62.91 and 7.89 ng mL-1 using molecularly imprinted polymer-bulk (mixture) and molecularly imprinted polymer-precipitation (mixture) respectively. Also, the sorbents showed selective behavior to extract ibuprofen in the presence of naproxen, fenoprofen, and ketoprofen. Overall, the results showed that the precipitation method in the mixture of acetonitrile/toluene resulted in the preparation of a sorbent with the highest extraction efficiency. Furthermore, a pharmacokinetic study was done. The maximum plasma concentration, the time required for maximum plasma concentration, and plasma half-life were 28.95 μg mL-1 , 2 h, and 2.39 h respectively. This article is protected by copyright. All rights reserved.

Waste to Treasure: Preparation of Functional Polymeric Particles from Waste Olefins in Carbolic Oil by Self-Stabilized Precipitation Polymerization

Carbolic oil is a fraction of coal tar with an enormous reserve, 40% of which are aromatic olefins such as indene, coumarone, styrene, etc. However, it is an underutilized r esource due to the lack of deep processing technology. In this study, we copolymerized olefins in the carbolic oil with maleic anhydride (MAh) by self-stabilized precipitation polymerization (2SP) method, to obtain uniform carbolic oil–maleic anhydride copolymer (CMA) particles with high yield (≥90%). Uniform CMA particles with a number-average molecular weight (Mn) in the range of 4400–24,100 g·mol–1 and particle sizes in the range of 150–2800 nm could be conveniently obtained by tuning the reaction factors. CMA exhibited good solubility in common organic solvents and possessed good thermal stability. After chemical modification of anhydride groups, CMA could be further converted into water-soluble carbolic oil–maleamic acid copolymers (CMAA), and heat-resistant and hydrophobic carbolic oil–maleimide copolymers (CMI). Overall, this research had provided a facile and green strategy for the effective utilization of waste olefins in carbolic oil, and the obtained copolymers had broad application prospects.