Surface Characterization and Dissociation Properties of Carboxylic Acid Core–Shell Latex Particle by Potentiometric and Conductometric Titration

Kawaguchi, Seigou; Yekta, Ahmad; Winnik, Mitchell A.

doi:10.1006/jcis.1995.9956

Cited by 85 publications

(97 citation statements)

References 10 publications

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Section: Introductionmentioning

confidence: 99%

“…The relationship between ψ o and σ is arrived at via the Poisson-Boltzmann equation (P-B); [1][2][3] however, experimental demonstration of the theory with colloid particles is still the subject of investigation. 3,4 For polymers and colloids with titratable ionophores, potentiometric titration provides a direct test of electrostatic theory. Thus, pH titration has been extensively used to evaluate the surface potential of proteins, [5][6][7][8] synthetic polyacids 3,9-14 and micelles; 15,16 however, all these systems exhibit complicating factors.…”

Section: Introductionmentioning

confidence: 99%

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Dissociation of Carboxyl-Terminated Cascade Polymers: Comparison with Theory

Zhang¹,

Dubin²,

Kaplan

et al. 1997

J. Phys. Chem. B

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The dissociation of carboxyl-terminated cascade polymers (generations 1-4) in 0.10 M NaCl has been studied by potentiometric titration. Experimental surface potentials were compared to the theoretical values calculated from the nonlinearized Poisson-Boltzmann equation. Experimental values are smaller than those predicted by theory for generations 2-4 in NaCl. The lower experimental potential is attributed in part to the effect of counterion binding, which is supported by the fact that significantly larger surface potentials are observed when Na + is replaced by tetramethylammonium ion (TMA + ). Potentials higher than those predicted by theory were observed at high degree of dissociation for generations 3 and 4 in TMACl, which may be due to the effect of the high surface charge density of cascade polymers on the local dielectric constant.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dissociation of Carboxyl-Terminated Cascade Polymers: Comparison with Theory

Zhang¹,

Dubin²,

Kaplan

et al. 1997

J. Phys. Chem. B

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“…The highest inflection point at about pH 8.3 is the second equivalence point and corresponds to the point of complete deprotonation of all methacrylic acid groups. 296 The respective contents of ionizable groups Q in the microgels were determined from the difference in amount of OH -between these points. In addition the third inflection point at about pH 6.3 represents the half equivalence point and denotes the pK a values of the microgels.…”

Section: Figure 54: Investigations On the Ph-dependent Swelling Behavmentioning

confidence: 99%

Light-Sensitive Polymeric Nanoparticles Based on Photo-Cleavable Chromophores

Klinger

2013

Springer Theses

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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.

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“…The dissociation behavior of various water-soluble polymers has been both experimentally and theoretically reported. [1][2][3][4][5][6][7][8] For a resist resolution in photolithography, acid dissociation of the resist polymers is one of the important factors. Although potentiometric titration is useful as a quantitative analysis of acid dissociation, direct measurements of the acidity of resist polymers cannot be performed by aqueous potentiometric titration since the polymers do not dissolve in water.…”

Section: Introductionmentioning

confidence: 99%