Highly pH and Temperature Responsive Microgels Functionalized with Vinylacetic Acid

Hoare, Todd; Pelton, Robert

doi:10.1021/ma035658m

Cited by 384 publications

(365 citation statements)

References 19 publications

Supporting

Mentioning

344

Contrasting

Unclassified

Order By: Relevance

“…The observed negative electrophoretic mobility and zeta potential for the microgel particles as shown in Figure 10 is due to the increasing surface charge density caused by the dissociation of carboxylic acid groups upon increasing the pH. 24 The electrophoretic mobility for the microgel particles also decreased above the LCST; as shown in Figure 9. This effect was caused by shrinkage of the hydrogel layer, which induces in enhances in the surface charge density.…”

Section: 폴리머 제37권 제6호 2013년mentioning

confidence: 96%

Preparation and Characterization of Novel Temperature and pH Sensitive (NIPAM-co-MAA) Polymer Microgels and Their Volume Phase Change with Various Salts

Khan¹,

Khan²,

Khan³

et al. 2013

Polymer Korea

View full text Add to dashboard Cite

Novel microgels of N-isopropylacrylamide (NIPAM)-co-methacrylic acid (MAA) (NIPAM-co-MAA) with different contents of N,N-methylene bis acrylamide (MBA) were prepared by emulsion polymerization technique and were studied by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and zeta potential measurement. Effect of pH, temperature and different salts concentration on the microgel particles was investigated. DLS results have shown that the hydrodynamic radius of the microgel increased upon increasing pH and decreased upon increasing temperature. The swelling/deswelling behaviors as determined by DLS showed the ionic repulsions of the carboxyl group of the methacrylic acid and hydrophobic interaction of NIPAM. The effect of various salts on volume phase transition temperature (VPTT) was also investigated. Upon increasing salt concentration, VPTT became broad and shifted to a lower temperature. Electrophoretic mobility measurements showed an increase with increasing pH and temperature at a constant ionic strength.

show abstract

Section: 폴리머 제37권 제6호 2013년mentioning

confidence: 96%

Preparation and Characterization of Novel Temperature and pH Sensitive (NIPAM-co-MAA) Polymer Microgels and Their Volume Phase Change with Various Salts

Khan¹,

Khan²,

Khan³

et al. 2013

Polymer Korea

View full text Add to dashboard Cite

show abstract

“…One type of commonly used co-monomers are organic acids such as vinylacetic, acrylic, methacrylic, allylacetic acid, etc. [1,[17][18][19][20], which leads not only to thermo-responsive microgels but also to pH responsive ones. There are some theoretical and experimental publications studying the influence of the co-monomer type and concentration on swelling/deswelling behaviour of charged microgel particles [17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Co-Monomer Content on the Swelling/Shrinking and Mechanical Behaviour of Individually Adsorbed PNIPAM Microgel Particles

et al. 2011

View full text Add to dashboard Cite

Abstract:The swelling/deswelling behaviour of microgel particles in the bulk and at the surface was studied and correlated to their mechanical properties. We focused on two kinds of particles: pure PNIPAM and PNIPAM-co-AAc particles. It was shown that the two step volume phase transition found for PNIPAM-co-AAc particles in the bulk disappears after the adsorption at the surface and only a one step transition was identified. The transition temperature increased strongly with increasing the co-monomer content. The dependence of the Young's modulus of the adsorbed microgel particles on the temperature and the co-monomer content was discussed. The investigations were performed via DLS and SFM.

show abstract

“…This effect can be desired and was already described earlier in the context of the influence of pH-sensitive groups on the VPTT of thermo-sensitive microgels (see chapter 3.3.2.1.1). 166 However, a differentiation between the individual responses to different stimuli can be achieved by the spatial separation of the specific functional groups responsible for the respective sensitivities. A sophisticated approach to realize this concept is the preparation of core/shell microgels consisting of different stimuli-responsive networkforming polymers in the core and the shell.…”

Section: Temperature-sensitive Microgelsmentioning

confidence: 99%

Light-Sensitive Polymeric Nanoparticles Based on Photo-Cleavable Chromophores

Klinger

2013

Springer Theses

View full text Add to dashboard Cite

This thesis focuses on the design, synthesis and characterization of novel photo-sensitive microgels and nanoparticles as potential materials for the loading and light-triggered release/accessibility of functional compounds. In order to realize this concept, different approaches to irradiation-dependent response mechanisms have been investigated.Novel light-cleavable divinyl functionalized monomeric crosslinkers based on o-nitrobenzyl derivatives were synthesized and used for the preparation of either PMMA or hydroxyl functionalized PHEMA microgels swellable and degradable in organic solvents. By the introduction of anionic MAA moieties into the PHEMA microgels, this concept was successfully transferred to double stimuli-responsive p(HEMA-co-MAA) hydrogel nanoparticles exhibiting a pH-dependent swelling and light-induced degradation behavior in aqueous media. This sensitivity to two orthogonal triggers is proposed to combine a pHinduced post-formation loading mechanism with a pH-and light-triggered release. In addition, a new class of enzyme-and light-sensitive PAAm microgels based on (meth-)acrylate functionalized dextrans as photo-and enzymatically degradable macromolecular crosslinkers was developed by introducing a photo-labile linker between the enzymatically degradable dextran chain and the polymerizable vinyl moieties. Here, the water solubility of the crosslinkers is assumed to enable an in situ loading approach of hydrophilic compounds.A different approach to the loading of microgels is based on photo-labile covalent microgel-drug conjugates. The first step to the realization of this concept was achieved by the development of a novel functional monomer consisting of a doxorubicin molecule covalently attached to a radically polymerizable methacrylate group via a photo-cleavable linker.Moreover, in order to enable the release of hydrophobic substances in aqueous media, hydrophobic nanoparticles consisting of a photo-resist polymer were designed to be degradable upon irradiation in water. Light-triggered conversion of the initial hydrophobic polymer into hydrophilic PMAA induced in situ particle dissolution and release of nile red.Since the introduction of a stimuli-responsive shell around a microgel is assumed to prevent leakage of embedded compounds, studies on non-stimuli-responsive shell formation around preformed microgel seed particles and the formation of microgel cores in polymeric shells were conducted to investigate potential synthetic pathways to this approach.In a last attempt, the surface of PHEMA and p(HEMA-co-MAA) microgels was functionalized with cinnamoyl groups in order to trigger the (reversible) particles interaction with each other by light-induced [2+2] cycloaddition reactions.

show abstract

Highly pH and Temperature Responsive Microgels Functionalized with Vinylacetic Acid

Cited by 384 publications

References 19 publications

Preparation and Characterization of Novel Temperature and pH Sensitive (NIPAM-co-MAA) Polymer Microgels and Their Volume Phase Change with Various Salts

Preparation and Characterization of Novel Temperature and pH Sensitive (NIPAM-co-MAA) Polymer Microgels and Their Volume Phase Change with Various Salts

The Effect of Co-Monomer Content on the Swelling/Shrinking and Mechanical Behaviour of Individually Adsorbed PNIPAM Microgel Particles

Light-Sensitive Polymeric Nanoparticles Based on Photo-Cleavable Chromophores

Contact Info

Product

Resources

About