Accurate Elemental Analysis of Metal‐Containing Polymer Latexes Using ICP‐Optical Emission Spectrometry

2012

Springer Theses

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This thesis focuses on the controlled assembly of monodisperse polymer colloids into ordered two-dimensional arrangements. These assemblies, commonly referred to as colloidal monolayers, are subsequently used as masks for the generation of arrays of complex metal nanostructures on solid substrates.The motivation of the research presented here is twofold. First, monolayer crystallization methods were developed to simplify the assembly of colloids and to produce more complex arrangements of colloids in a precise way. Second, various approaches to colloidal lithography are designed with the aim to include novel features or functions to arrays of metal nanostructures.The air/water interface was exploited for the crystallization of colloidal monolayer architectures as it combines a two-dimensional confinement with a high lateral mobility of the colloids that is beneficial for the creation of high long range order. A direct assembly of colloids is presented that provides a cheap, fast and conceptually simple methodology for the preparation of ordered colloidal monolayers. The produced two-dimensional crystals can be transformed into nonclose-packed architectures by a plasma-induced size reduction step, thus providing valuable masks for more sophisticated lithographic processes. Finally, the controlled co-assembly of binary colloidal crystals with defined stoichiometries on a Langmuir trough is introduced and characterized with respect to accessible configurations and size ratios.Several approaches to lithography are presented that aim at introducing different features to colloidal lithography. First, using metal-complex containing latex particles, the synthesis of which is described as well, symmetric arrays of metal nanoparticles can be created by controlled combustion of the organic material of the colloids. The process does not feature an inherent limit in nanoparticle size and is able to produce complex materials as will be demonstrated for FePt alloy particles. Precise control over both size and spacing of the particle array is presented.Second, two lithographic processes are introduced to create sophisticated nanoparticle dimer units consisting of two crescent shaped nanostructures in close proximity; essentially by using a single colloid as mask to generate two structures simultaneously. Strong coupling processes of the parental plasmon resonances of the two objects are observed that are accompanied by high near-field enhancements. A plasmon hybridization model is elaborated to explain all polarization dependent shifts of the resonance positions. Last, a technique to produce laterally patterned, ultra-flat substrates without surface topographies by embedding gold nanoparticles in a silicon dioxide matrix is applied to construct robust and re-usable sensing architectures and to introduce an approach for the nanoscale patterning of solid supported lipid bilayer membranes.

“…[174] Accurate elemental analysis of metal-containing polymer latexes using inductively coupled plasma -optical emission spectrometry 61…”

Section: Resultsmentioning

confidence: 99%

Section: Incorporation Of Metal Complexes By Miniemulsion Polymerizationmentioning

confidence: 99%

Surface Patterning with Colloidal Monolayers

2012

Springer Theses

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“…Scheme 1 shows the mechanism of the seeded emulsion polymerization process. Latex particles loaded with platinum acetylacetonate as a model compound for a functional molecule, were prepared by a conventional miniemulsion polymerization process [24]. The reaction parameters are specified in the Experimental section.…”

Section: Resultsmentioning

confidence: 99%

“…After completion, the resulting particles were dialyzed in order to remove the unreacted initiator and monomer. Previously, it has been shown by inductively coupled plasma optical emission spectrometry (ICP-OES) that a seeded emulsion polymerization process does not change the amount of platinum acetylacetonate in the particle [24]. …”

Section: Resultsmentioning

confidence: 99%

Platinum nanoparticles from size adjusted functional colloidal particles generated by a seeded emulsion polymerization process

Beilstein J. Nanotechnol.

Ziener

Manzke³

et al. 2011

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SummaryThe benefits of miniemulsion and emulsion polymerization are combined in a seeded emulsion polymerization process with functional seed particles synthesized by miniemulsion polymerization. A systematic study on the influence of different reaction parameters on the reaction pathway is conducted, including variations of the amount of monomer fed, the ratio of initiator to monomer and the choice of surfactant and composition of the continuous phase. Critical parameters affecting the control of the reaction are determined. If carefully controlled, the seeded emulsion polymerization with functional seed particles yields monodisperse particles with adjustable size and functionalities. Size-adjusted platinum-acetylacetonate containing latex particles with identical seed particles and varied shell thicknesses are used to produce arrays of highly ordered platinum nanoparticles with different interparticle distances but identical particle sizes. For that, a self-assembled monolayer of functional colloids is prepared on a solid substrate and subsequently treated by oxygen plasma processing in order to remove the organic constituents. This step, however, leads to a saturated state of a residual mix of materials. In order to determine parameters influencing this saturation state, the type of surfactant, the amount of precursor loading and the size of the colloids are varied. By short annealing at high temperatures platinum nanoparticles are generated from the saturated state particles. Typically, the present fabrication method delivers a maximum interparticle distance of about 260 nm for well-defined crystalline platinum nanoparticles limited by deformation processes due to softening of the organic material during the plasma applications.

“…Here, we introduce a possible solution to overcome both the toxicity of the plain particles and to increase their stability towards oxidation and aggregation by encapsulation in polymeric colloidal particles. Miniemulsion polymerization was chosen as the method for the encapsulation as it has been shown to be a powerful tool to incorporate a variety of materials including magnetite particles into polymeric latex particles . In contrast to conventional emulsion polymerization, the latex particles in a direct miniemulsion process (oil‐in‐water) are not formed by diffusion of monomer to the polymerization locus.…”

Section: Introductionmentioning

confidence: 99%

Magnetic Polymer/Nickel Hybrid Nanoparticles Via Miniemulsion Polymerization

Staudt

Machado

Macro Chemistry & Physics

et al. 2013

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This work shows a method to synthesize and encapsulate magnetic nickel nanocrystals into polymeric colloidal particles through miniemulsion polymerization. The nickel nanoparticles are produced by a thermal decomposition method in the presence of oleylamine and triphenylphosphine, which results in a hydrophobic surface. However, being compatible with the monomer does not ensure a successful encapsulation by miniemulsion polymerization, as the nickel nanoparticles are expelled from the polymer particles with increasing styrene conversion due to the poor adhesion interaction between the organic shells of the nickel nanoparticles and the polystyrene. Changing the hydrophobic polystyrene to a polymer with higher polarity such as poly(methyl methacrylate) proves to be efficient for encapsulation of nickel nanoparticles when employing a hydrophilic initiator. After encapsulation, these nanoparticles show magnetic response.