Microfluidic synthesis of metal oxide nanoparticles via the nonaqueous method

Stolzenburg, Pierre; Lorenz, Thomas; Dietzel, Andreas; Garnweitner, Georg

doi:10.1016/j.ces.2018.07.007

Cited by 37 publications

(23 citation statements)

References 67 publications

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“…Furthermore, it was determined that the K a value for the synthesized CeO 2 nanorods was approximately 80% higher than batch synthesized particles, which is attributable to the smaller particle sizes and higher surface areas enabled by microfluidic syntheses. [96] Stolzenburg et al [97] then demonstrated the syntheses of TiO 2 , ZnO, and CeO 2 using a single microfluidic reactor and chemistry. Nanocrystals were synthesized by mixing titanium(IV) isopropoxide, zinc(II) acetylacetonate hydrate, or cerium(III) chloride in benzyl alcohol, which was then fed into a microfabricated PDMS reactor and formed into droplets via flow focusing using Fluoronox 1008 as the continuous phase.…”

Section: Metal Oxide Nanoparticlesmentioning

confidence: 99%

Microfluidic Synthesis of Semiconductor Materials: Toward Accelerated Materials Development in Flow

Campbell

Bateni

Volk

et al. 2020

Part & Part Syst Charact

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Semiconductors are intriguing due to their unique electrical properties, particularly the behavior of their electrons in the presence of different stimuli (e.g., electric field, magnetic field, light irradiation), which differ greatly from conducting (i.e., metals) and insulating materials. In insulators and semiconductors, the available electronic states are discontinuous, with the existence of a gap between the lower energy states, commonly referred to as the valence band (VB), and the higher energy states, known as the conduction band (CB). The distinguishing factor between these materials is the size of the energy difference between the highest energy state in the VB and the lowest energy state in the CB, called the band gap. In insulators, the band gap is very large, making it difficult, if not impossible, to cause an electron to move from the VB to the CB. By comparison, semiconductors possess narrow to moderate band gaps, implying that it is possible to introduce enough energy to an electron to cause it to move from the VB to the CB, enabling electron transfer, the use of high energy electrons, or the emission of energy (i.e., photons) when the electron returns from the CB to the VB. The wide range of industrial application-specific requirements demands versatility in the target characteristics of semiconductor materials (e.g., size, morphology, composition, band gap, emission wavelength), which are vastly different from those commonly used in thin-film transistors. Typically, the semiconductor materials synthesized for use in the above applications are particulate materials produced across a range of sizes spanning five orders of magnitude (from just a few nm to hundreds of µm), and can be divided into two overarching categories, nano-and microsized particulate materials. Nanosized semiconductor materials, due in large part to their miniscule dimensions, present a variety of intriguing characteristics not observed in microsized semiconductor particles. First and foremost, if the dimensions of the semiconductor material decrease below a certain threshold known as the Bohr radius, the absorption and emission energies become highly dependent on the particle size, a phenomenon known as quantum confinement. [28-30] Moreover, nanosized structures have significantly larger surface-to-volume ratios which increases the surface contribution to the total free energy of the semiconductor materials, making them highly soluble [29] and therefore much easier to process and handle. Thus far, nanosized semiconductor particles have been effectively utilized in sensors, [7] LEDs, [9] Controlled synthesis of semiconductor nano/microparticles has attracted sub stantial attention for use in numerous applications from photovoltaics to photo catalysis and bioimaging due to the breadth of available physicochemical and optoelectronic properties. Microfluidic material synthesis strategies have recently been demonstrated as an effective technique for rapid development, controlled synthesis, and continuous manufacturing of solutionpr...

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Section: Metal Oxide Nanoparticlesmentioning

confidence: 99%

Microfluidic Synthesis of Semiconductor Materials: Toward Accelerated Materials Development in Flow

Campbell

Bateni

Volk

et al. 2020

Part & Part Syst Charact

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“…However, in laminar flow conditions in straight miniaturized channels, convective mass transport perpendicular to the flow direction does not occur and mixing occurs by slower Taylor–Aris dispersion [22]. Various geometric designs for microfluidic systems were proposed to speed up the mixing, like flow-focusing or lamination mixers [23,24,25,26,27]. A further method of a more efficient mixing process is the segmentation of the continuous flow with a low miscible medium such as gas, which results in a periodic gas–liquid flow, a so-called ‘Taylor flow’ [28,29].…”

Section: Introductionmentioning

confidence: 99%

Stabilized Production of Lipid Nanoparticles of Tunable Size in Taylor Flow Glass Devices with High-Surface-Quality 3D Microchannels

et al. 2019

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Nanoparticles as an application platform for active ingredients offer the advantage of efficient absorption and rapid dissolution in the organism, even in cases of poor water solubility. Active substances can either be presented directly as nanoparticles or can be integrated in a colloidal carrier system (e.g., lipid nanoparticles). For bottom-up nanoparticle production minimizing particle contamination, precipitation processes provide an adequate approach. Microfluidic systems ensure a precise control of mixing for the precipitation, which enables a tunable particle size definition. In this work, a gas/liquid Taylor flow micromixer made of chemically inert glass is presented, in which the organic phases are injected through a symmetric inlet structure. The 3D structuring of the glass was performed by femtosecond laser ablation. Rough microchannel walls are typically obtained by laser ablation but were smoothed by a subsequent annealing process resulting in lower hydrophilicity and even rounder channel cross-sections. Only with such smooth channel walls can a substantial reduction of fouling be obtained, allowing for stable operation over longer periods. The ultrafast mixing of the solutions could be adjusted by simply changing the gas volume flow rate. Narrow particle size distributions are obtained for smaller gas bubbles with a low backflow and when the rate of liquid volume flow has a small influence on particle precipitation. Therefore, nanoparticles with adjustable sizes of down to 70 nm could be reliably produced in continuous mode. Particle size distributions could be narrowed to a polydispersity value of 0.12.

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“…Microfluidic systems have proven to be a great platform for the synthesis and optimization of various nanoparticles including metal and metal oxide nanoparticles, semiconductors, colloidal nanoparticles, and hybrid organic–inorganic nanoparticle composites [19,20,21,22,23]. The formation of niosomes can be achieved via microfluidics by applying a controlled laminar mixing of two or more inlet streams, whereupon precipitation of the surfactant and subsequent self-assembly into the product occur [24,25].…”

Section: Introductionmentioning

confidence: 99%

Rapid Microfluidic Preparation of Niosomes for Targeted Drug Delivery

Şeleci

Maurer

Stahl

et al. 2019

IJMS

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Niosomes are non-ionic surfactant-based vesicles with high promise for drug delivery applications. They can be rapidly prepared via microfluidics, allowing their reproducible production without the need of a subsequent size reduction step, by controlled mixing of two miscible phases of an organic (lipids dissolved in alcohol) and an aqueous solution in a microchannel. The control of niosome properties and the implementation of more complex functions, however, thus far are largely unknown for this method. Here we investigate microfluidics-based manufacturing of topotecan (TPT)-loaded polyethylene glycolated niosomes (PEGNIO). The flow rate ratio of the organic and aqueous phases was varied and optimized. Furthermore, the surface of TPT-loaded PEGNIO was modified with a tumor homing and penetrating peptide (tLyp-1). The designed nanoparticular drug delivery system composed of PEGNIO-TPT-tLyp-1 was fabricated for the first time via microfluidics in this study. The physicochemical properties were determined through dynamic light scattering (DLS) and zeta potential analysis. In vitro studies of the obtained formulations were performed on human glioblastoma (U87) cells. The results clearly indicated that tLyp-1-functionalized TPT-loaded niosomes could significantly improve anti-glioma treatment.

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Microfluidic synthesis of metal oxide nanoparticles via the nonaqueous method

Cited by 37 publications

References 67 publications

Microfluidic Synthesis of Semiconductor Materials: Toward Accelerated Materials Development in Flow

Microfluidic Synthesis of Semiconductor Materials: Toward Accelerated Materials Development in Flow

Stabilized Production of Lipid Nanoparticles of Tunable Size in Taylor Flow Glass Devices with High-Surface-Quality 3D Microchannels

Rapid Microfluidic Preparation of Niosomes for Targeted Drug Delivery

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