scholarly journals Polyacids as Modulators for the Synthesis of UiO-66

2019 ◽  
Vol 72 (10) ◽  
pp. 848 ◽  
Author(s):  
Kyle C. Bentz ◽  
Sergio Ayala ◽  
Mark Kalaj ◽  
Seth M. Cohen
Keyword(s):  
Particle Size ◽  
Raft Polymerization ◽  
Metal Organic Framework ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Reversible Addition ◽  
Metal Organic ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
University Of Oslo

Poly(acrylic acid) (PAA) and poly(vinylbenzoic acid) (PBA) were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization and used as modulators for the synthesis of the metal–organic framework (MOF) UiO-66 (UiO=University of Oslo). Whereas typical syntheses of UiO-66 require large excesses of acid modulators, such as acetic acid or benzoic acid, to achieve controlled particle size and morphology of the resulting MOF particles, the use of polymerized acids allows for narrow particle size distributions at sub-stoichiometric quantities of modulator. We show using scanning electron microscopy and dynamic light scattering techniques that polyacids can act as alternative modulators for the growth of UiO-66.

Control of Particle Size and Morphology of MOF-199 Crystals via a Reaction-Diffusion Framework

2017 ◽  
Vol 380 ◽  
pp. 39-47 ◽  
Author(s):  
Razan Issa ◽  
Mohamad Hmadeh ◽  
Mazen Al-Ghoul
Keyword(s):  
Particle Size ◽  
Copper Ions ◽  
Metal Organic Framework ◽  
Diffusion Flux ◽  
Reaction Diffusion ◽  
Metal Organic ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
And Control ◽  
Organic Linker

A reaction-diffusion framework (RDF) is used to synthesize and control the size and morphology of single crystals of metal-organic framework-199 (MOF-199). The framework consists of diffusing copper ions (Cu2+, outer electrolyte) into a hydrogel medium containing the organic linker, 1,3,5-benzenetricarboxylic acid (BTC, inner electrolyte). The resulting supersaturation gradient, and its nonlinear coupling with nucleation and growth kinetics, provides means to control the crystal size, distrubution and morphology along the diffusion flux. This method is rapid, efficient, scalable, and environmentally friendly. By using this method we demonstrate how assorted experimental parameters, such as temperature, concentrations, and nature of the gel matrix can be easily tuned to produce different particle size distributions and various morphologies.

RAFT-Mediated Emulsion Polymerization of Styrene in Water using a Reactive Polymer Nanoreactor

2009 ◽  
Vol 62 (11) ◽  
pp. 1528 ◽  
Author(s):  
Carl N. Urbani ◽  
Michael J. Monteiro
Keyword(s):  
Particle Size ◽  
Diblock Copolymer ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Final Particle ◽  
Reactive Polymer ◽  
Highly Active ◽  
Molecular Weight Distributions ◽  
Reversible Addition ◽  
And Control

We have demonstrated a nanoreactor methodology to produce polystyrene nanoparticles with narrow molecular weight distributions (MWD) and control over the final particle size distributions. Our reactive thermoresponsive diblock copolymer nanoreactor is an ideal setting to carry out otherwise difficult reversible addition–fragmentation chain transfer (RAFT)-mediated polymerizations, resulting in surfactant-free nanoparticles that can be tuned to size and MWD. By confining the MacroRAFT agent within the nanoreactor, the poor P(DMA68-b-NIPAM73)-SC(=S)SC4H9 (PNIPAM) leaving group on the MacroCTA behaves as a highly active MacroCTA through kinetic rather than thermodynamic control. The Mn was close to theory with low polydispersity indices (PDIs) (<1.2). The particle size increased with the ratio of styrene to nanoreactors and with very narrow particle size distributions. However, we found that there was a limited amount of styrene monomer that can be encapsulated into the nanoreactor, leading to polymerizations stopping well before full conversion. This problem was overcome through the addition of a non-reactive thermoresponsive diblock copolymer, which resulted in Mns close to 340 K and low PDIs. Manuscript received: 15 April 2009. Manuscript accepted: 15 July 2009.

254. A Comparison of the Particle Size Distributions for Aerosols Generated During Wet Grinding and Dry Deburring of Beryllium

1999 ◽  
Author(s):  
K.K. Ellis ◽  
R. Buchan ◽  
M. Hoover ◽  
J. Martyny ◽  
B. Bucher-Bartleson ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Wet Grinding

Measurements of Mineral Particle Size Distributions by a Buoyancy Weighing Method

2010 ◽  
Vol 126 (10/11) ◽  
pp. 577-582 ◽  
Author(s):  
Katsuhiko FURUKAWA ◽  
Yuichi OHIRA ◽  
Eiji OBATA ◽  
Yutaka YOSHIDA
Keyword(s):  
Particle Size ◽  
Mineral Particle ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Weighing Method

Certain Problems with the Application of Stochastic Diffusion Processes for the Description of Chemical Engineering Phenomena. Diffusional Change of Solid Particle Size

1996 ◽  
Vol 61 (4) ◽  
pp. 536-563
Author(s):  
Vladimír Kudrna ◽  
Pavel Hasal
Keyword(s):  
Particle Size ◽  
Solid Particle ◽  
Chemical Engineering ◽  
Diffusion Processes ◽  
Granular Systems ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Diffusion Term ◽  
Population Balances ◽  
And Diffusion

To the description of changes of solid particle size in population, the application was proposed of stochastic differential equations and diffusion equations adequate to them making it possible to express the development of these populations in time. Particular relations were derived for some particle size distributions in flow and batch equipments. It was shown that it is expedient to complement the population balances often used for the description of granular systems by a "diffusion" term making it possible to express the effects of random influences in the growth process and/or particle diminution.

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