Robin N Klupp Taylor

Friedrich-Alexander-University of Erlangen-Nürnberg | FAU · Department of Chemical and Biological Engineering

Alginate dialdehyde-gelatin (ADA-GEL) hydrogels are being studied in bioprinting for their combination of cell adhesion and printability. To incorporate specific functionalities and to improve printability, different additives to ADA-GEL inks are being proposed. Here, a novel type of functional nanoparticles comprising silver patches on silica core...

https://zenodo.org/records/11264121

Plasmonic nanoparticles have intriguing optical properties which make them suitable candidates for sensing or theranostic applications. Anisotropic patchy particles, where metal is locally deposited on the surface of a core particle, exhibit plasmon resonances that can be specifically adjusted for these applications. However, many existing synthesi...

We describe the development of a T-mixer based continuous flow process for the coating of 86–500 nm diameter spherical polystyrene particles with thin gold patches by heterogeneous nucleation and growth. After establishing a suitable flow rate for good mixing and sufficiently uniform product morphology we systematically investigate the main reactio...

Patchy particles, which comprise a core particle of one material partially covered by a thin layer of another, offer great promise for tailored particle-based materials and devices in the future. This study concerns the investigation and improvement of a potentially gram-scalable continuous flow process based on a cascade of two T-mixers for the sy...

Patchy particles, which comprise a core particle of one material partially covered by a thin layer of another, offer great promise for tailored particle-based materials and devices in the future. This study concerns the investigation and improvement of a potentially gram-scalable continuous flow process based on a cascade of two T-mixers for the sy...

An important application of metal oxide pigments, especially iron oxide, is the coloration of concrete. This application places special requirements on a pigment due to the harsh chemical, thermal, and mechanical environments of the application as well as the expectation of very long‐term stability. Metal oxide pigments are a significant subclass o...

Anisotropic nanoparticles offer considerable promise for applications but also present significant challenges in terms of their characterization. Recent developments in the electroless deposition of silver patches directly onto colloidal silica particles have opened up a simple and scalable synthesis method for patchy particles with tunable optical...

A process for manufacturing goethite containing the steps: a) Dissolution of ferric (III) nitrate in water b) Treatment of the solution obtained according to step a) at a temperature in the range of 55° to 65° C, c) Isolating the goethite from the suspension obtained according to step b) d) Suspending the isolated goethite of step c) in water e) Tr...

The performance of secondary batteries, of which the lithium‐ion battery is one of the most well known, depends not only on the active electrode materials but also on the electrode architecture. In particular, the reduction in electrode tortuosity is expected to enable batteries with high active material utilization and fast charging and dischargin...

A hematite pigment having i) an aspect ratio AR of lower than 1.5, preferably lower than 1.3, most preferably lower than 1.2, ii) a CIELAB a* value of ≥ 28.5, in particular from 29 to 33, iii) a CIELAB b*-value of ≤ 71 % of the CIELAB a* value, preferably ≤ 70% of the CIELAB a* value iv) a CIELAB L* value of ≥ 39, in particular from 40 to 43, prefe...

We describe the fabrication and morphological and electrochemical characterisation of lithium ion battery anodes whereby the active material is supported on flake-like microparticles. Using various physical analytical techniques we verify that nanostructured cobalt (II, III) oxide can be directly grown onto commercial titanium dioxide-coated mica f...

The haze factor, which describes the fraction of light that is scattered when passing through a transparent material, is of general importance for any optical device, from milk glass shielding visibility while providing ambient lighting to solar cells that are optimized by sophisticated light management layers. Often, such active layers are fabrica...

The formation of thin silver patches on colloidal silica spheres using a Tollen's-like reaction with very low metal ion concentration and high excess of reducing agent is investigated. Through systematic variation of reaction parameters, electron microscopy and optical spectroscopy we elucidate why the crystalline coating grows conformal to the cur...

The natural world is a colorful environment. Stunning displays of coloration have evolved throughout nature to optimize camouflage, warning, and communication. The resulting flamboyant visual effects and remarkable dynamic properties, often caused by an intricate structural design at the nano‐ and microscale, continue to inspire scientists to unrav...

Iron oxides and iron oxyhydroxides find wide applications as magnetic materials, adsorbents for wastewater treatment and pigments. This study addresses the formation of anisotropic α-FeOOH (goethite) nanorods during air oxidation of ferrous hydroxide slurries. The effects of concentration and aeration rate on reaction kinetics and particle size and...

Thin films containing metal nanohole arrays can be fabricated with high precision, and regular, tunable features via colloidal lithography. They are ideal model structures to study the relation between structural design and optoelectronic properties, for example as transparent, conducting electrodes, where the percolation threshold sets an upper li...

The formation of positively charged polystyrene latex particles via the surfactant-free emulsion polymerization of styrene with cationic initiator is investigated. Using the comonomer (vinylbenzyl)trimethyl-ammonium chloride (VBTMAC) it is shown that the particle size can be tuned rather precisely between above 350 nm and below 70 nm. The simple fu...

An emerging topic in the field of biomaterials is the incorporation of silver ions, metallic silver or silver oxides into bioactive glasses to impart novel functionalities. In this work, a new approach of surface functionalization of 45S5 bioactive glass (BG) is introduced. In contrast to more common methods, which are based on the inclusion of sil...

In the current paper, mesocrystals are used as effective precursors to design nanoreactors with different kinds of enclosed porosity. The thermal treatment of hematite mesocrystalline nanoparticles is investigated as a post-processing tool for the engineering of internal organization of hierarchical structures. The porosity of starting materials an...

Mesocrystalline particles have been recognized as a class of multifunctional materials with potential applications in different fields. However, the internal organization of nanocomposite mesocrystals and its influence on the final properties have not yet been investigated. In this paper, a novel strategy based on electrodynamic simulations is deve...

Dendrite growth of metal patches on colloidal particles shows a variety of structures depending on the preparation conditions. The morphology of these patches suggests a cross-over from a reaction to a diffusion limited growth, implicating diffusion on the particle surface. Interestingly, the morphological and optical characteristics of the patches...

Dielectric-metal core-shell particles with morphologically tunable optical properties are highly promising candidates for applications ranging from theranostics, energy harvesting and storage to pigments and sensors. Most structures of interest have, until now, been produced in small volume wet chemical batch approaches which are difficult to scale...

The ability to confine and manipulate light below the diffraction limit is a major goal of future multifunctional optoelectronic/plasmonic systems. Here, we demonstrate the design and realization of a tunable and localized electrical source of excitons coupled to surface plasmons based on a polymer light-emitting field-effect transistor (LEFET). Go...

Mechanical properties and particle breakage behavior in the submicron size range are of fundamental importance for many particle related processes and applications. Although many (in situ) studies have been dedicated to materials’ size dependent mechanical characterization, particles as free standing structures have been omitted widely. An importan...

Iron oxides and iron oxyhydroxides particles, particularly the goethite α-FeOOH phase, are environmentally friendly materials and are used in various technological applications as adsorbents, precursors of Fe powders for magnetic recording media, and pigments. In this work, the formation process of α-FeOOH by air oxidation of Fe(OH)2 suspensions ha...

A phosphonic acid functionalized triphenylphosphine rhodium complex was synthesized and grafted onto neat superparamagnetic iron oxide nanoparticles. The material was investigated by elemental analysis, IR spectroscopy, thermogravimetric analysis, XRD, N2-physisorption analyses, and TEM measurements. The obtained hybrid material could be used as a...

In this contribution we discuss luminescent down-shifting (LDS) systems consisting of a polymer matrix filled with phosphor particles. It is an elegant approach to make a use of potentially destructive or otherwise wasted high energy photons and diminish charge carrier losses caused by thermalization in photovoltaics. Sub-micron and micron sized pa...

Metal oxide nanomaterials find application in diverse fields of research and industry such as catalysis, drug delivery, sensing, photo-electrochemistry, optical detection or as pigments [1,2]. The materials properties and hence application performance are affected by the particle size, shape, surface characteristics as well as by possible pore or d...

The Stöber–Fink–Bohn (SFB) method allows the synthesis of spherical silica particles over a wide size range. Owing to the complex formation mechanism, the internal structure and related mechanical properties are not well understood. Within this account, the internal structure of synthesized SFB particles is changed systematically by heat treatments...

Gold nanoshells on 1.1 µm diameter silica cores were produced via a seeded growth approach and their quality evaluated using optical measurements. The particles were combined with polycaprolactone to produce a flexible biocompatible composite film with high conductivity (1.51 S cm−1) and relatively low effective gold loading (16.86 wt%) in comparis...

Nanostructured particles containing noble metals can have highly tunable localized surface plasmon resonances and are therefore of particular interest for numerous applications. Nanoshells comprising a dielectric core and gold or silver shell are a widely researched system due to the strong dependence of their optical properties on the ratio of cor...

Patchy particles comprise regions of differing material or chemical functionality on otherwise isotropic cores. To meet the great potential of these anisotropic structures in a wide range of application fields, completely new approaches are sought for the scalable and tunable production of patchy particles, particularly those with nanoscale dimensi...

Small particles are exploited for their optical properties in a vast array of applications such as paint, inks, textiles and cosmetics. In many of these application areas, features of the particles (size, shape and topology) can be on the nanoscale, a fact which is often fundamentally important to their desirable properties. With the broad range of...

The electrophoretic deposition (EPD) technique is an attractive approach for development of graphene and graphene oxide (GO) films for a variety of applications. However, in order to establish the influence of the EPD parameters on the properties of the deposited films, a deeper investigation of the fundamental GO-EPD kinetics is required. Previous...

Extremely small, monodisperse, and spheric maghemite (γ-Fe2O3, 2–3 nm) and manganese (4–7 nm), cobalt (3–5 nm), and zinc ferrite (5–7 nm) nanocrystals are directly accessible on a large scale starting from inexpensive metal powders and octanoic acid by thermolysis in a high-boiling solvent. Bigger particle size is obtainable by prolonged reaction t...

The present invention relates to methods for synthesis of metallic island coatings with tunable island coverage and morphology on a variety of Substrates. Particularly, the present invention relates to Substrates coated with one or more metal islands and the use of said island-coated Substrates.

This work addresses the determination of arbitrarily shaped particle size distributions (PSDs) from PbS and PbSe quantum dot (QD) optical absorbance spectra in order to arrive at a relationship between band gap energy and particle size over a large size range. Using a modified algorithm which was previously developed for ZnO, we take only bulk abso...

A novel strategy for the immobilization of a sulfonate functionalized triphenylphosphine ligand by ion-ion interactions on an imidazolium modified SBA-15 is presented. A support containing electrostatically grafted triphenylphosphine as the ligand was reacted with PdCl 2(CNPh) 2 and the resulting hybrid material catalyzed olefin hydrogenation under...

Here we report that silver nanoparticle necklaces can be readily formed by treatment of colloidal silica with ammoniacal silver complex solution followed by washing, deposition and ageing. We investigate the morphology of the produced materials and elucidate the key variables that influence this promising new approach to one-dimensional nanostructu...

Patchy particles possessing heterogeneous surface composition show great promise as self-organizing building blocks for new classes of hierarchical functional structures. A major hurdle is the scalable synthesis of stable patches on nanosized core particles with arbitrarily defined patch number and coverage. So far, few methods have been reported w...

Mesoporous organosilica materials with different contents of bistrialkoxysilyl imidazolium salts in the framework were synthesized by a one-step synthesis. Textural characterization of the materials confirmed that the morphology and surface properties of the imidazolium-bridged organosilicas depended critically on the amount of organic groups in th...

The formation of spherical superparamagnetic colloidal aggregates of magnetite nanoparticles by emulsification of a ferrofluid and subsequent solvent evaporation has been systematically studied. The colloidal aggregates occur as a dense sphere with magnetite nanoparticles randomly packed and preserved particle-particle separation due to chemisorbed...

For the comprehensive characterization of nanoparticles cross-sectional investigation on the atomic scale by analytical and high-resolution transmission electron microscopy (TEM) is indispensable. Cross-sectioning is especially important for anisotropic nanoparticles to gain information on structure and chemistry along all important projections. We...

Patchy particles possessing heterogeneous surface composition show great promise as self-organizing building blocks for new classes of hierarchical functional structures. A major hurdle is the scalable synthesis of stable patches on nanosized core particles with arbitrarily defined patch number and coverage. So far, few methods have been reported w...

Mesocrystals are a promising class of nanomaterials enabling new optical and mechanical properties due to their three dimensional organization of primary crystallites sharing a common crystallographic orientation. In the present article, the influence of process parameters such as temperature profile and stirring on the primary and secondary size o...

Cellulose nanocrystals, which can be isolated from natural cellulose fibres by controlled acid hydrolysis, are promising biomolecule templates for the fabrication of hierarchical organised materials. In this work, we addressed the problem of gold deposition on cellulose and silica-coated cellulose nanocrystals to form metal nanowires. Nanostructure...

A group of hierarchically ordered PMOs with large cage-like pores are prepared with organosilica units including ethylene, ethenylene, and phenylene-bridged silanes. The structure and hydrophobicity of these materials are shown to offer significant advantages for the physical adsorption of lipase from aqueous media and also markedly enhance its act...

The one-pot synthesis of patchy particles with morphologically tunable optical properties by the heterogeneous nucleation and growth of silver onto colloidal silica particles is described. Heat treatment of the silica and coating reaction conditions can be optimized in order to produce full yields of patchy particles. Dissolution of the cores leads...

The visual appearance of the artificial world is largely governed by films or composites containing particles with at least one dimension smaller than a micron. Over the past century and a half, the optical properties of such materials have been scrutinized and a broad range of colorant products, based mostly on empirical microstructural improvemen...

The preparation of hierarchical large-pore cage-type periodic mesoporous organosilicas is reported in a Communication by Zhou et al. (on p. 2627). The hydrophobicity and structure of these novel materials are benefi cial for lipase entrapment and provide signifi cantly enhanced activity and stability compared to the native enzyme.

A Mobil Composition of Matter (MCM)-41 type mesoporous silica material containing N-propylacridone groups has been successfully prepared by co-condensation of an appropriate organic precursor with tetraethyl orthosilicate (TEOS) under alkaline sol-gel conditions. The resulting material was fully characterized by means of X-ray diffraction (XRD), N(...

Polymers and coordinating solvents have been shown to serve as templating agents to assist the precipitation of ZnO nanoparticles and address their morphology. In this work we show for the first time that a difference in the coordination strength between the polymer (poly-N-vinylpyrrolidone (PVP)) and the two Zn(II) precursor salts (nitrate and ace...

Mono- and multilayer graphene sheets have been successfully produced from commercial graphite powder in a wet grinding process under mild milling conditions. The shear forces in the milling chamber lead to a continuous delamination of ultrathin graphene flakes which are dispersed in a liquid medium. To avoid agglomeration of the exfoliated flakes t...

Here we demonstrate, for the first time, the heterogeneous nucleation and growth of silver patches on submicrometer silica spheres. While patches can be grown directly onto native silica particles, it is shown that a higher patch yield can be obtained by first treating the silica with a mixture of an alkanolamine and silver nitrate. Variation of th...

The structure formation and charge transfer of thin nanoparticulate indium tin oxide (ITO) films prepared by dip-coating was studied as a function of stabilizer before and after annealing at different temperatures. The analysis of the film structure by optical methods revealed that it is a function of the stability. Suspensions containing an optimu...

We present a model to calculate particle size distributions (PSDs) of colloidal ZnO nanoparticles from their absorbance spectra. Using literature values for the optical properties of bulk ZnO and correlating the measurement wavelengths in the UV-visible regime with distinct particle sizes by a tight binding model (TBM), an algorithm deconvolutes th...

The investigation of ZnO nanoparticles is of great interest due to the wide range of potential applications for this material. Despite this, a thorough understanding of the optical, electronic and structural properties of ZnO nanoparticles with respect to their synthesis is still lacking. We tackled this problem by synthesizing ZnO nanoparticles wi...

Semiconductor quantum dots are finding numerous applications in biological systems; in this paper, we report the simple in situ preparation of nucleotide capped cadmium sulfide (CdS) nanoparticles and investigate the interaction of the capping agent with the nanoparticle surface.

The hetero-polyoxometalate (POM) Na13[Eu(SiMoW10O39)2] displayed enhanced luminescence when coordinated to compounds with a common amine functionality. The POM was then doped into silica spheres and was found to be confined to the particle core when added with an amine-based polymer.