Macroporous poly(EGDMA-co-HEMA) networks: Morphological characterization from their behaviour in the swelling process

Gómez, Cesar Gerardo; Pastrana, Gustavo; Serrano, Daniel; Zuzek, E.; Villar, Marcelo A.; Strumia, Miriam Cristina

doi:10.1016/j.polymer.2012.04.040

Cited by 21 publications

(33 citation statements)

References 35 publications

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“…Variations in porosity from 84 % for networks with 33 % EGDMA to 66 % for those with 6 % EGDMA have been reported. 42 After significant water evaporation the profiles resemble the initial ones of the nonswollen samples, in which the water content is evenly distributed. As will be shown below, this event corresponds to the deswelling of the polymer matrix.…”

Section: Spatially Resolved Water Content During Dryingmentioning

confidence: 88%

“…6a). 42 A precise determination of the dimensions of the different pores and the relation with the amount of water retained on the surface is a complex problem that is subject to further studies.…”

Section: Spatially Resolved Water Content During Dryingmentioning

confidence: 99%

“…will dominate the relaxation measurement. For this reason, in this work we correlate information obtained in a relaxometer with a homogeneous magnetic field with that attained from profiles acquired with the surface scanner.The study was performed using polymer beads with hierarchical pore structure corresponding to copolymers of ethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate [poly(EGDMAco-HEMA)] synthesized as previously reported 42. For the suspension polymerization reaction cyclohexane was used as a porogenic agent, PVP as a suspension stabilizer and BPO was used as a radical initiator.…”

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confidence: 99%

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Spatially Resolved Monitoring of Drying of Hierarchical Porous Organic Networks

et al. 2016

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Evaporation kinetics of water confined in hierarchal polymeric porous media is studied by low field nuclear magnetic resonance (NMR). Systems synthesized with various degrees of cross-linker density render networks with similar pore sizes but different response when soaked with water. Polymeric networks with low percentage of cross-linker can undergo swelling, which affects the porosity as well as the drying kinetics. The drying process is monitored macroscopically by single-sided NMR, with spatial resolution of 100 μm, while microscopic information is obtained by measurements of spin-spin relaxation times (T2). Transition from a funicular to a pendular regime, where hydraulic connectivity is lost and the capillary flow cannot compensate for the surface evaporation, can be observed from inspection of the water content in different sample layers. Relaxation measurements indicate that even when the larger pore structures are depleted of water, capillary flow occurs through smaller voids.

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Section: Spatially Resolved Water Content During Dryingmentioning

confidence: 88%

Section: Spatially Resolved Water Content During Dryingmentioning

confidence: 99%

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confidence: 99%

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Spatially Resolved Monitoring of Drying of Hierarchical Porous Organic Networks

et al. 2016

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“…Porous polymeric scaffolds have a wide range of applications and can be prepared with a controlled hierarchy of micro-, meso-, and macroporous spatial domains. 9,10,11,12 Because of the hydrophilic characteristic of these materials, water not only diffuses into pore structures, but also swells the network developing a layer of gel inside the material. A gel phase usually exhibits a better performance in terms of accessibility to specific active sites on the surface, 13 however its mechanical properties hinder the span of possible applications.…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, when the porous media is saturated with a fluid which is able to swell the polymer, changes in the porosity can be expected. 10 Nuclear magnetic resonance (NMR) is a suitable technique for the study of molecular dynamics of different liquids confined in porous matrices. Several methods based on monitoring the restricted diffusion of liquid molecules confined in a porous matrix, and their relaxation properties render information of void size, pore interconnectivity and liquid-surface interactions.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Surface Interaction of Water Confined in Hierarchical Porous Polymers Induced by Hydrogen Bonding

et al. 2016

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Hierarchical porous polymer systems are increasingly applied to catalysis, bioengineering, or separation technology because of the versatility provided by the connection of mesopores with percolating macroporous structures. Nuclear magnetic resonance (NMR) is a suitable technique for the study of such systems as it can detect signals stemming from the confined liquid and translate this information into pore size, molecular mobility, and liquid-surface interactions. We focus on the properties of water confined in macroporous polymers of ethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate [poly(EGDMA-co-HEMA)] with different amounts of cross-linkers, in which a substantial variation of hydroxyl groups is achieved. As soft polymer scaffolds may swell upon saturation with determined liquids, the use of NMR is particularly important as it measures the system in its operational state. This study combines different NMR techniques to obtain information on surface interactions of water with hydrophilic polymer chains. A transition from a surface-induced relaxation in which relaxivity depends on the pore size to a regime where the organic pore surface strongly restricts water diffusion is observed. Surface affinities are defined through the molecular residence times near the network surface.

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Preparation and characterizations of superparamagnetic iron oxide‐embedded poly(2‐hydroxyethyl methacrylate) nanocarriers

Gupta

Bajpai

2014

J of Applied Polymer Sci

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The present study aims at formulating a novel multifunctional biocompatible superparamagnetic nanoparticles carrier system with homogeneously dispersed magnetic material in solid polymer matrix of poly(2‐hydroxyethyl methacrylate) (PHEMA). The nanocomposites were designed by modified suspension polymerization of 2‐hydroxyethyl methacrylate followed by in situ coprecipitation of iron oxide inside the nanoparticle matrix yielding magnetic PHEMA (mPHEMA) nanocomposites. The so prepared nanocomposites were characterized by Fourier transform Infrared spectroscopy, X‐ray diffraction technique, Raman spectroscopy, electron diffraction, and energy‐dispersive X‐ray spectroscopy confirming the presence of Fe3O4 inside the PHEMA nanoparticles. The magnetization studies of nanocomposites conducted at room temperature using vibrating sample magnetometer suggested for their superparamagnetic nature having saturation magnetization (Ms) of 20 emu/g at applied magnetic field of 5 kOe. Transmission electron microscopy, field‐emission scanning electron microscopy, and dynamic light scattering/zeta potential measurements were also performed which revealed that size of mPHEMA nanocomposites was lying in the range of 60–300 nm having zeta potential of −93 mV. The nanocomposites showed no toxicity as revealed by cytotoxicity test performed on L‐929 fibroblast by extract method. The results indicated that the prepared superparamagnetic mPHEMA nanocomposites have enormous potential to provide a possible option for magnetically assisted targeted delivery of anticancer drugs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40791.

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Macroporous poly(EGDMA-co-HEMA) networks: Morphological characterization from their behaviour in the swelling process

Cited by 21 publications

References 35 publications

Spatially Resolved Monitoring of Drying of Hierarchical Porous Organic Networks

Spatially Resolved Monitoring of Drying of Hierarchical Porous Organic Networks

Enhanced Surface Interaction of Water Confined in Hierarchical Porous Polymers Induced by Hydrogen Bonding

Preparation and characterizations of superparamagnetic iron oxide‐embedded poly(2‐hydroxyethyl methacrylate) nanocarriers

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