Observations on some copolymerisations involving N -isopropylacrylamide

Xue, Wei; Champ, Simon; Huglin, Malcolm B.

doi:10.1016/s0032-3861(00)00171-3

Cited by 69 publications

(61 citation statements)

References 25 publications

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“…15 In the design of dual smart materials, acidic pH responsive polymers have been well exploited, for example, by incorporating acrylic acid, methacrylic acid, undecanoic acid or maleic acid as monomers. [29][30][31][32]47,48 Despite their efficiency, these systems have limitations in terms of biocompatibility 49 or thermoresponsive control. In this work, we introduced a pH switch as a second stimulus for the thermoresponsive nanogels.…”

Section: Dual Ph-temperature Responsive Nanogelsmentioning

confidence: 99%

“…28 Where dual functionalities have been investigated, the approach has commonly involved the introduction of pH responsive monomers, such as acrylic acid (AAc), methacrylic acid or 4-vinylpyridine. [29][30][31][32] Despite significant advances, the relationship between the chemical composition of the polymerisation mixtures and the properties of the materials is yet to be fully understood. This significantly limits the development of further applications.…”

Section: Introductionmentioning

confidence: 99%

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An l-proline based thermoresponsive and pH-switchable nanogel as a drug delivery vehicle

Salinas

Resmini

2018

Polym. Chem.

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The synthesis and characterisation of a novel dual stimuli-responsive nanogel, based on thermoresponsive N-n-propylacrylamide and an L-proline based monomer acting as a pH-switcher, is reported here. The effect of the crosslinker/co-monomer ratios was studied to demonstrate the relationship between the chemical structure, degree of hydrophobicity and physico-chemical characteristics of the nanogels. Tailoring of the thermoresponsive properties was achieved by altering crosslinker N,N'-methylenebis (acrylamide) content between 10 and 50 mol%, in combination with three thermoresponsive monomers N-n-isopropylacrylamide, N-n-propylacrylamide and N-acryloylpyrrolidine. A library of 25 different combinations of monomers and crosslinkers was obtained and characterised by dynamic light scattering and UV-Vis spectroscopy. The nanogel based on N-n-propylacrylamide and 10 mol% crosslinker was then co-polymerised with an L-proline based monomer to introduce a pH-switch. This nanogel was obtained with <10 nm particle size and a VPTT ca. 43°C, and was used to demonstrate a drug delivery capability using Nile Blue A as a model drug. Detailed studies demonstrated maximum drug release at lower pH and 43°C, thus confirming the dual stimuli switch.

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Section: Dual Ph-temperature Responsive Nanogelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An l-proline based thermoresponsive and pH-switchable nanogel as a drug delivery vehicle

Salinas

Resmini

2018

Polym. Chem.

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“…The reactivity of comonomers determined the sequence of blocks. According to literatures, [35,36] the sequence of reactivity of comonomers was the following: NIPAM > AA > DEA. In other words, NIPAM had priority to be grafted from the surface of PS cores as competing with AA monomer and then polymerized with AA at the last stage of polymerization.…”

Section: Resultsmentioning

confidence: 99%

Fabrication and characterization of bifunctional spherical polyelectrolyte brushes

Cang

Zhang

Fang

et al. 2016

Designed Monomers and Polymers

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In this work, we prepared two kinds of dual-responsive spherical polyelectrolyte brushes (SPBs) with narrow distribution, of which cores were composed of polystyrene and grafting from copolymers of poly(N-isopropyl acrylamide-co-acrylic acid) (P(NIPAM-AA)) and poly(acrylic acid-co-N,N-diethyl acrylamide) (P(AA-DEA)), respectively. Both kinds of SPBs could response to pH and temperature stimulations by swelling/deswelling shell and electrophoretic mobility (EPM) changes. The low critical solution temperature of SPBs can be fine-tuned in the range of 28-45 ℃ at pH 3-9. Due to the different reactivity of comonomers (NIPAM and AA or DEA and AA), the acrylic acid (AA) unties were distributed at the inner shell of P(AA-DEA) and outer shell of P(NIPAM-AA), respectively, which led to different responses toward pH, temperature, and ionic strength, such as the abnormal 'salt effect' of P(AA-DEA) at low ionic strength and lower shell shrinkage ratio (SR) of P(NIPAM-AA). The dye adsorption in SPBs further confirmed the distribution of AA units.

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“…In case of NIPAM/MAA copolymerization, reactivity ratios of r NIPAM = 10.2 and r MAA = 0.01 are reported (Xue et al, 2000). Consequently, since in both cases r NIPAM >>1>> r DADMAC/MAA , the compositional homogeneity up to quite a high conversion of NIPAM for those copolymers is presumed.…”

Section: Flocculationmentioning

confidence: 87%

Flocculation of flotation tailings using thermosensitive polymers

Bogacz

Lemanowicz

Gierczycki

et al. 2017

Chemical and Process Engineering

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The key feature of thermosensitive polymers is the reversible transition between the hydrophilic and hydrophopic forms depending on the temperature. Although the main research efforts are focused on their application in different kinds of drug delivery systems, this phenomenon also allows one to precisely control the stability of solid-liquid dispersions. In this paper research on the application of poly(N-isopropylacrylamide) copolymers in processing of minerals is presented. In the experiments tailings from flotation plant of one of the coal mines of Jastrzębska Spółka Węglowa S.A. (Poland) were used. A laser particle sizer Fritsch Analysette 22 was used in order to determine the Particle Size Distribution (PSD). It was proved that there are some substantial issues associated with the application of thermosensitive polymers in industrial practice which may exclude them from the common application. High salinity of suspension altered the value of Lower Critical Solution Temperature (LCST). Moreover, the co-polymers used in research proved to be efficient flocculating agents without any temperature rise. Finally, the dosage needed to achieve steric stabilization of suspension was greatly beyond economic justification.

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Observations on some copolymerisations involving N -isopropylacrylamide

Cited by 69 publications

References 25 publications

An l-proline based thermoresponsive and pH-switchable nanogel as a drug delivery vehicle

An l-proline based thermoresponsive and pH-switchable nanogel as a drug delivery vehicle

Fabrication and characterization of bifunctional spherical polyelectrolyte brushes

Flocculation of flotation tailings using thermosensitive polymers

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