An Ordered Nanoporous Monolith from an Elastomeric Crosslinked Block Copolymer Precursor

Cavicchi, Kevin A.; Zalusky, Andrew S.; Lodge, Timothy P.

doi:10.1002/marc.200300245

Cited by 58 publications

(69 citation statements)

References 20 publications

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“…The preparation of porous polymeric materials has been reported with pore sizes ranging from some nanometers to some micrometers. The sacrificial components used to generate nanopores in BCP precursors are diversified and include poly(dimethylsiloxane) (PDMS), [8][9][10] poly(propylene glycol) (PPG), 11 polyisoprene (PI) 12 or poly(methyl methacrylate) 50 (PMMA) 13,14 that can be degraded by reaction with HF or tetrabutyl ammonium fluoride, oxygen plasma treatment (or degradation in presence of fuming nitric acid), ozonolysis or UV irradiation followed by acetic acid extraction, respectively. 5-7 40 In this particular case, the copolymer is composed of at least one sacrificial block that should allow for well-defined porosity after a selective etching process.…”

Section: Introductionmentioning

confidence: 99%

“Clickable” thiol-functionalized nanoporous polymers: from their synthesis to further adsorption of gold nanoparticles and subsequent use as efficient catalytic supports

2015

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A straightforward and versatile approach towards thiol-functionalized nanoporous polystyrene frameworks is reported through the selective cleavage of a disulfide bridge at the junction between both blocks of newly synthesized polystyrene-block-poly(D,L-lactide) (PS-b-PLA) diblock 10 copolymer precursors. This methodology requires the synthesis of a disulfide-bearing heterodifunctional initiator that allows for the production of well-defined diblock copolymers by combining atom transfer radical polymerization (ATRP) of styrene and ring-opening polymerization (ROP) of D,L-lactide. After macroscopic orientation of the copolymer precursors through channel die processing and subsequent quantitative degradation of the disulfide bridge via 15 triphenylphosphine-mediated reduction, thiol-functionalized porous polymers are obtained. Further, "click" thiol-ene-mediated functionalization of thiol-coated pore walls within nanoporous frameworks is implemented. More interestingly, adsorption of in-situ generated gold nanoparticles and subsequent and unprecedented supported catalytic reduction of a model nitroaromatic compound, i.e. para-nitrophenol, are successfully achieved. Reusability of the hybrid catalyst is also 20 proved over a 5 run-cycle with conversion of nearly 70% within only two hours. a n, m : number-average polymerization degrees of PS or PLA blocks as determined by 1 H NMR b Conversion as determined by gravimetry c Mn theor = conversion × DPn × Mo(styrene) or Mn theor = conversion × DPn × Mo (LA) + Mn NMR (PS-OH) d Mn NMR : number-average molar mass evaluated by 1 H NMR e SEC measurements with polystyrene standards f Volume fraction of PLA as calculated by 1 H NMR, assuming that the densities of PS and PLA are 1.02 and 1.25, respectively 85 Thiol-coated nanoporous materials were successfully engineered from diblock polystyrene-block-poly(D,L-lactide) precursors possessing a disulfide junction. The further immobilization of GNPs at the pore surface provided novel supported nanocatalysts for the efficient reduction of p-nitrophenol.

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Section: Introductionmentioning

confidence: 99%

“Clickable” thiol-functionalized nanoporous polymers: from their synthesis to further adsorption of gold nanoparticles and subsequent use as efficient catalytic supports

2015

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“…The chemical cross-linking of PS-b-PLA thin films using RuO 4 has been explored with subsequent removal of the PLA to give a cross-linked nanoporous film. 13 Other studies have appeared on the use of dicumyl peroxide to cross-link polyisoprene-b-polydimethylsiloxane (PIb-PDMS) with subsequent removal of the PDMS phase 11,12 and poly(R-methylstyrene)-b-poly(4-hydroxystyrene) (PRMS-b-PHOST) systems using a photoacid generator to promote cross-linking. 20 However, the addition of small molecules has limitations, including the incorporation of undesirable chemical functionality or metals associated with the cross-linking reaction.…”

Section: Introductionmentioning

confidence: 99%

A Thermal and Manufacturable Approach to Stabilized Diblock Copolymer Templates

Leiston-Belanger¹,

Russell²,

Drockenmuller³

et al. 2005

Macromolecules

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Stabilization of the morphology in thin diblock copolymer films is critical for the generation of robust templates for subsequent device fabrication. Copolymers containing thermally cross-linkable groups, such as benzocyclobutene (BCB), can be annealed to induce an ordered microdomain morphology and then subsequently heated to cross-link the system, locking in the morphology and eliminating the need for multistep processing. Poly[(styrene-r-BCB)-b-lactic acid] (PSBCB-b-PLA) was synthesized by a combination of living free radical and ring-opening polymerizations. Thin films (∼30 nm) of PSBCB-b-PLA annealed at 170°C, followed by cross-linking at 200°C, showed that the ordered and oriented microdomain morphology was preserved. For PSBCB-b-PLA, with PLA volume fractions of 0.24 and 0.36, arrays of cylindrical microdomains of PLA oriented normal to the surface were produced in a crosslinked PS matrix. Washing these films with a weak base degraded and removed the PLA, producing a nanoporous cross-linked template.

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“…The use of polynorbornene backbones allows the system to be crosslinked after alignment, such that mechanically robust films are produced. This is a key point as it prevents the collapse of nanopores due to Laplace pressure …”

mentioning

confidence: 99%

Thermally Switchable Aligned Nanopores by Magnetic‐Field Directed Self‐Assembly of Block Copolymers

et al. 2014

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An Ordered Nanoporous Monolith from an Elastomeric Crosslinked Block Copolymer Precursor

Cited by 58 publications

References 20 publications

“Clickable” thiol-functionalized nanoporous polymers: from their synthesis to further adsorption of gold nanoparticles and subsequent use as efficient catalytic supports

“Clickable” thiol-functionalized nanoporous polymers: from their synthesis to further adsorption of gold nanoparticles and subsequent use as efficient catalytic supports

A Thermal and Manufacturable Approach to Stabilized Diblock Copolymer Templates

Thermally Switchable Aligned Nanopores by Magnetic‐Field Directed Self‐Assembly of Block Copolymers

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