Continuous flow synthesis of phase transition-resistant titania microparticles with tunable morphologies

Campbell, Zachary S.; Jackson, Daniel; Lustik, Jacob; Al-Rashdi, Amur K.; Bennett, Jeffrey A.; Li, Fanxing; Abolhasani, Milad

doi:10.1039/d0ra01442g

Cited by 7 publications

(10 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Flow Synthesis Procedure . Droplets of the appropriate precursor mixture were formed using the axisymmetric flow focusing device using the previously reported procedure [21,23] . Briefly, after droplet formation, the ETPTA present in the precursor was polymerized in operando using a collimated UV LED (365 nm, ThorLabs M365LP1 C), after which the photocrosslinked particles were collected in a vial containing pure formamide.…”

Section: Methodsmentioning

confidence: 99%

Flow Synthesis of Single and Mixed Metal Oxides

et al. 2022

Self Cite

View full text Add to dashboard Cite

A generalizable and versatile microfluidic approach for facile synthesis of a wide range of metal oxide microparticles using atypical metal‐organic precursors is reported. Microparticles of three single oxide materials, zinc(II) oxide, tin(IV) oxide, and cerium(IV) oxide, as well as a binary rare earth mixed oxide, lanthanum(III) praseodymium(III) oxide, are synthesized in flow. The tin(IV) oxide is shown to vary in composition from 14.2 % to 0 % orthorhombic phase at annealing temperatures ranging from 500 °C to 900 °C, while the lanthanum(III) praseodymium(III) oxide forms at a relatively low temperature of ∼700 °C.

show abstract

Section: Methodsmentioning

confidence: 99%

Flow Synthesis of Single and Mixed Metal Oxides

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Nitrogen (N 2 , grade 5.0) and CO 2 (industrial-grade) were purchased from Messer. The graphite-titania (G-TiO 2 composite) microspheres used to pack the flow reactor were synthesized using a flow-focusing microreactor presented previously by our group. − However, rather than annealing the microparticles at 500 °C, the in-flow synthesized microparticles were calcined under ambient atmosphere at 400 °C, which resulted in the formation of G-TiO 2 composite microparticles. Deionized (DI) water (18 MΩ-cm) was generated using the on-site facility.…”

Section: Methodsmentioning

confidence: 99%

Continuous Flow Solar Desorption of CO₂ from Aqueous Amines

Campbell

Han

Marre

et al. 2021

ACS Sustainable Chem. Eng.

Self Cite

View full text Add to dashboard Cite

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

show abstract

“…The second category, tube or capillary-based microreactors ( Figure 2B), are commonly constructed from inexpensive, commercially-available components such as metal or polymer tubing, [64] glass capillaries, [65,66] and needles, with little, if any, modification. The use of these materials often enables facile (off-the-shelf) microreactor construction at a fraction of the time and cost associated with microfabricated reactor assembly.…”

Section: Types Of Microscale Flow Chemistry Platformsmentioning

confidence: 99%

“…It was found that the resulting microspheres possessed surface areas up to 259 m 2 g -1 and resisted phase transition to the rutile phase even at temperatures up to 800 °C ( Figure 4D). Following the development of a hybrid hydrolytic-oxidative process for TiO 2 synthesis, Campbell et al [66] combined the reported flowfocusing microreactor using a formamide continuous phase with in situ UV crosslinking to intensify the synthetic process and almost fully eliminate hydrolysis ( Figure 4E). The integration of a collimated UV LED (385 nm) with the microreactor enabled the use of TBT concentrations ranging from 12-50 wt% TBT and synthesis of a wide variety of morphologies including hollow, yolk-shell, thick shell, macroporous, and dense microspheres.…”

Section: Metal Oxide Microparticlesmentioning

confidence: 99%

“…I) diagram of the flow-focusing microreactor with in situ UV photocrosslinking, II) graph of surface areas achieved at various TBT and ETPTA concentraions, III) SEM images of TiO 2 microparticles synthesized using the oxidative pathway (adapted with permission. [66] Copyright 2020, Royal Society of Chemistry [116] Copyright 2018, Elsevier).…”

Section: Chalcogenidesmentioning

confidence: 99%

See 1 more Smart Citation

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

Campbell

Bateni

Volk

et al. 2020

Part & Part Syst Charact

Self Cite

View full text Add to dashboard Cite

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...

show abstract

Continuous flow synthesis of phase transition-resistant titania microparticles with tunable morphologies

Abstract: A flow chemistry strategy for synthesis of anatase titania microparticles utilizing a flow-focusing microreactor integrated with a collimated UV LED is presented. The synthesized microparticles possess a wide variety of morphologies and high surface areas (up to 362 m2 g−1).

Cited by 7 publications

References 46 publications

Flow Synthesis of Single and Mixed Metal Oxides

Flow Synthesis of Single and Mixed Metal Oxides

Continuous Flow Solar Desorption of CO₂ from Aqueous Amines

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

Contact Info

Product

Resources

About

Continuous flow synthesis of phase transition-resistant titania microparticles with tunable morphologies

Abstract: A flow chemistry strategy for synthesis of anatase titania microparticles utilizing a flow-focusing microreactor integrated with a collimated UV LED is presented. The synthesized microparticles possess a wide variety of morphologies and high surface areas (up to 362 m2 g−1).

Cited by 7 publications

References 46 publications

Flow Synthesis of Single and Mixed Metal Oxides

Flow Synthesis of Single and Mixed Metal Oxides

Continuous Flow Solar Desorption of CO2 from Aqueous Amines

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

Contact Info

Product

Resources

About

Continuous Flow Solar Desorption of CO₂ from Aqueous Amines