EDC/NHS activation mechanism of polymethacrylic acid: anhydride versus NHS-ester

Yan, Qin; Zheng, Hongning; Jiang, Chen; Li, Kun; Xiao, Shou‐Jun

doi:10.1039/c5ra13844b

Cited by 78 publications

(69 citation statements)

References 34 publications

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“…They can also be prepared or easily available in the market as end‐functionalized macromolecules. Then, for example, amino‐terminated PEOPPO can be coupled to carboxylate groups of a polymer backbone by the addition of carbodiimides, to obtain graft copolymers . Literature has extensively shown the use of polysaccharides as the backbone, such as carboxymethylcellulose, sodium alginate, pullulan, dextran, and even carboxymethyl tamarind and carboxymethyl guar .…”

Section: Introductionmentioning

confidence: 99%

HPAM‐g‐PEOPPO: Rheological modifiers in aqueous media of high temperature and high ionic strength

Lima

Marques

Villetti

et al. 2019

J of Applied Polymer Sci

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Partially hydrolyzed polyacrylamide (HPAM) is widely used as thickener in enhanced oil recovery (EOR), but the high temperature and salinity of oil reservoirs can reduce the viscosity and lead to polymer precipitation. To improve the performance of HPAM in high‐salinity and high‐temperature environments, the responsive amino‐terminated poly(ethylene oxide‐co‐propylene oxide) (PEOPPO) (EO/PO = 19/03) was grafted onto a HPAM backbone. The copolymers were prepared in water using 1‐ethyl‐3‐[3‐(dimethylamino)‐propyl]carbodiimide hydrochloride/N‐hydroxysuccinimide (EDC/NHS) as activators. Structural characterization was performed by 1H NMR and Fourier transform infrared (FTIR) and the responsive behavior was investigated by UV–Vis and rheology. Spectroscopic analyses confirmed that copolymers were successfully synthesized. UV–Vis showed that copolymers have combined salt and thermoresponsive character. Rheology in saline medium (ionic strength = 3.75 mol.L−1) revealed that, contrary to unmodified HPAM, HPAM‐g‐PEOPPO have thermothickening behavior and also higher viscosity than HPAM at 70 °C, suggesting the utilization of these copolymers as rheological modifiers under harsh conditions of temperature and salinity, such as the ones found in EOR applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47453.

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Section: Introductionmentioning

confidence: 99%

HPAM‐g‐PEOPPO: Rheological modifiers in aqueous media of high temperature and high ionic strength

Lima

Marques

Villetti

et al. 2019

J of Applied Polymer Sci

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“…It has been suggested before that the formation of an ester leads to the appearance of troughs around 1818 cm -1 , 1784 cm -1 and 1743 cm -1 [21] [22], but given the natural frequency of the ATR tool crystal we used, it was impossible to detect anything on the bands ranging from 1800 cm -1 to 2600 cm -1 . As such, we only report a trough at 1745 cm -1 , which we expect is attributed to the formation of an ester group (as it does not appear before SAM activation).…”

Section: Ftirmentioning

confidence: 89%

Immobilization of DNA probes on a high frequency piezoelectric biosensor

Monsalve

González

Grajales

2020

DYNA

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In recent years, researchers have taken to biosensors as effective tools for detection due to their portability, low-cost, fast response, and practicality. Piezoelectricity gave way to quartz crystal microbalances (QCM), of which high-frequency QCMs (HFF-QCM 100MHz) are still being researched. In this paper, we use DNA immobilization on a HFF-QCM via self-assembled monolayers (SAM) technique. Immobilization was initially verified with ATR-FTIR. Then, DNA was immobilized in real time on the HFF-QCM crystals. A variation in the phase of the signal suggests fixation of DNA to the surface, in accordance with ATR-FTIR results. A density of 629 ng/cm2 was computed. Also, a positive correlation between immobilized DNA and DNA concentration, and the appearance of a saturation point between 1 and 5 μM were shown after analysis of different DNA concentrations.

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“…The activated films incubated in collagen solution (1 mg/ml, pH = 3.7) at 4 C for 8 hr and washed with distilled water to immobilize positive charge collagen on the PU films. [12,35] Then collagen immobilized films were dipped in PSS solution (1 mg/ml) for 30 min to generate a negative charge on the surface of the PU films and again washed with distilled water.…”

Section: Surface Modification Before Lbl Self-assemblymentioning

confidence: 99%

Layer‐by‐layer self‐assembly of collagen and chitosan biomolecules on polyurethane films

Bahrami

Khorasani

Mahdavi

et al. 2020

J of Applied Polymer Sci

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Polyurethane (PU) films used in wound dressing applications often have appropriate properties. Still, surface modification is necessary to increase the biocompatibility. In this research, the surface of the PU films was modified with collagen and chitosan biomolecules through layer by layer (LbL) self‐assembly process. The PU films were synthesized from castor oil and hexamethylene diisocyanate. Then, they were treated with low‐pressure nitrogen plasma to graft with poly(acrylic acid). Before performing the LbL process, the surfaces of the PU films were modified using three different reagents, including (A) NaOH solution, (B) EDC/NHS solution, or (C) hexamethylene diamine. Then, the collagen and chitosan deposited in three and five layers on the surface. The images of FESEM, confocal microscopy, and AFM showed that the best performance of the LbL deposition process was after the surface modification with hexamethylenediamine (HMDA). The MTT assay showed that the presence of these biomolecules had boosted the proliferation of fibroblast cells. Increasing the number of the deposited layer from three to five, decreased the cell viability and antibacterial activity of the films. The obtained results propose the modification with HMDA and the deposition of three layers of collagen and chitosan on the PU films to improve its biocompatibility.

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EDC/NHS activation mechanism of polymethacrylic acid: anhydride versus NHS-ester

Abstract: Both stable intermediates of anhydride and NHS-ester were observed after EDC/NHS activation of PMAA, where NHS-ester waxes, while anhydride wanes complementarily with increasing fragmentation degree of PMAA blocks in PMAA-associated polymer blends.

Cited by 78 publications

References 34 publications

HPAM‐g‐PEOPPO: Rheological modifiers in aqueous media of high temperature and high ionic strength

HPAM‐g‐PEOPPO: Rheological modifiers in aqueous media of high temperature and high ionic strength

Immobilization of DNA probes on a high frequency piezoelectric biosensor

Layer‐by‐layer self‐assembly of collagen and chitosan biomolecules on polyurethane films

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