References of "Du Prez, Filip E"
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See detailPoly(acrylic acid) with disulfide bond for the elaboration of pH-responsive brush surfaces
Van Camp, Wim; Du Prez, Filip E; Alem, Halima et al

in European Polymer Journal (2010), 46(2), 195-201

We report on a new route for the facile prepn. of pH-responsive tethered brushes on metallic surfaces, starting from poly(acrylic acid) (PAA) contg. a disulfide (S-S) bond (PAA-S-S-PAA). First, atom ... [more ▼]

We report on a new route for the facile prepn. of pH-responsive tethered brushes on metallic surfaces, starting from poly(acrylic acid) (PAA) contg. a disulfide (S-S) bond (PAA-S-S-PAA). First, atom transfer radical polymn. (ATRP) of 1-ethoxyethyl acrylate (EEA) with a disulfide-contg. initiator was performed to obtain the poly(EEA) precursor polymer (PEEA-S-S-PEEA). Deprotection of PEEA by a heating step resulted in the desired PAA chains without any further purifn. The brushes, obtained by the grafting to' of PAA-S-S-PAA onto gold, were then characterized by at. force microscopy in water at various pH values. The results evidence a large collapsing/swelling capacity. [less ▲]

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See detailpH-Responsive diblock copolymers prepared by the dual initiator strategy
Bernaerts, Katrien V.; Willet, Nicolas ULg; Van Camp, Wim et al

in Macromolecules (2006), 39(11), 3760-3769

Diblock copolymers poly(tetrahydrofuran-b-tert-butyl acrylate) (PTHF-b-PtBA) and poly(tetrahydrofuranb- 1-ethoxyethyl acrylate) (PTHF-b-PEEA) were successfully synthesized by the dual initiator 4 ... [more ▼]

Diblock copolymers poly(tetrahydrofuran-b-tert-butyl acrylate) (PTHF-b-PtBA) and poly(tetrahydrofuranb- 1-ethoxyethyl acrylate) (PTHF-b-PEEA) were successfully synthesized by the dual initiator 4-hydroxybutyl-2- bromoisobutyrate (HBBIB). The isobutyrate and alcohol function of HBBIB were used for the atom transfer radical polymerization of tBA ( or EEA) and the living cationic ring-opening polymerization of THF, respectively. Hydrolysis or thermolysis of the aforementioned diblock copolymers results in amphiphilic pH-responsive copolymers PTHF-b-poly( acrylic acid) ( PTHF-b-PAA). Matrix-assisted laser desorption/ ionization time-of-flight (MALDI-TOF) and nuclear magnetic resonance spectroscopy (H-1 NMR) were used to analyze the PTHF macroinitiator, while clear evidence for the formation of well-defined block copolymer structures was obtained by 1H NMR, gel permeation chromatography (GPC), and infrared spectroscopy (FT-IR). The amorphous PtBA block in PTHF-b-PtBA resulted in a decrease of the crystallinity and the melting point of PTHF, as shown by differential scanning calorimetry (DSC). Self-assembly of PTHF-b-PAA copolymers in water into aggregates and micelles when exposed to specific pH values was confirmed by dynamic light scattering, infrared, and NMR spectroscopies. [less ▲]

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See detailDesign of stealth nanoparticles for drug delivery based on new amphiphilic copolymers
Rieger, Jutta ULg; Passirani, Catherine; Dubois, Philippe et al

Conference (2006, May 18)

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See detailControlled synthesis of an ABC miktoarm star-shaped copolymer by sequential ring-opening polymerization of ethylene oxide, benzyl beta-malolactonate, and epsilon-caprolactone
Rieger, Jutta ULg; Coulembier, Olivier; Dubois, Philippe ULg et al

in Macromolecules (2005), 38(26), 10650-10657

This paper reports on the synthesis of an amphiphilic miktoarm ABC star-shaped copolymer, s[(PEO)(PMLABz)(PCL)], consisting of biocompatible/bioresorbable arms. Indeed, PEO is a hydrophilic biocompatible ... [more ▼]

This paper reports on the synthesis of an amphiphilic miktoarm ABC star-shaped copolymer, s[(PEO)(PMLABz)(PCL)], consisting of biocompatible/bioresorbable arms. Indeed, PEO is a hydrophilic biocompatible poly(ethylene oxide) arm, PMLABz is a poly(benzyl beta-malolactonate) arm precursor of a pH-sensitive bioresorbable poly(beta-malic acid) block, and PCL is a hydrophobic bioresorbable poly(epsilon-caprolactone) arm. Each constitutive arm was prepared by ring-opening polymerization. A double-headed PEO macroinitiator [PEO-(OH)-COO-K+] was first prepared by selective hydrolysis of the alpha-lactone (2-oxepanone) end group of PEO chains end-capped by a omega-methoxy group. The anionic polymerization of benzyl beta-malolactonate (MLABz) was selectively initiated by the alpha-potassium carboxylate end group of PEO in the presence of 18-crown-6 ether. The polymerization of epsilon-caprolactone (epsilon-CL) was initiated by the hydroxyl group left at the junction of the two blocks of the as-prepared PEO-b-PMLABz diblock copolymer, in the presence of tin(II) bis(2-ethylhexanoate) (Sn(Oct)(2)). The macroinitiator, the intermediate diblock, and the final miktoarm. star-shaped copolymer were analyzed by H-1 NMR spectroscopy and size exclusion chromatography. [less ▲]

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See detailAssociation behavior of thermo-responsive block copolymers based on poly(vinyl ethers)
Verdonck, Béatrice; Gohy, Jean-François; Khousakoun, Eric et al

in Polymer (2005), 46(23), 9899-9907

Thermo-sensitive nanosized structures have been prepared in water from poly(methyl vinyl ether)-block-poly(isobutyl vinyl ether) (PMVE-b-PIBVE) block copolymers. The composition and the architecture ... [more ▼]

Thermo-sensitive nanosized structures have been prepared in water from poly(methyl vinyl ether)-block-poly(isobutyl vinyl ether) (PMVE-b-PIBVE) block copolymers. The composition and the architecture (diblock and triblock architectures) of the PMVE-b-PIBVE copolymers have been varied. The investigated copolymers had an asymmetric composition with a major PMVE block, While the PIBVE blocks are hydrophobic, the PMVE blocks are hydrophilic at room temperature and become hydrophobic above their demixing temperature (around 36 degrees C) as a result of the lower critical solution temperature (LCST) behavior. At room temperature, the amphiphilic copolymers aggregate in water above a critical micelle concentration, which has been experimentally measured by hydrophobic dye solubilization. The hydrodynamic diameter of the structures formed above the cmc has been measured by dynamic light scattering (DLS) while their morphology has been studied by transmission electron microscopy (TEM). H-1 NMR measurements in D2O at room temperature reveal that the aggregates contain PIBVE insoluble regions surrounded by solvated PMVE chains. These investigations have shown that polydisperse spherical micelles are formed for asymmetric PMVE-b-PIBVE copolymers containing at least 9 IBVE units. For copolymers containing less IBVE units, loose aggregates are formed. Finally, the thermo-responsive, reversible properties of these structures have been investigated. Above the cloud point of the copolymers, the loose aggregates precipitate while the micelles form large spherical structures. [less ▲]

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See detailLactone end-capped poly(ethylene oxide) as a new building block for biomaterials
Rieger, Jutta ULg; Bernaerts, Katrien V.; Du Prez, Filip E et al

in Macromolecules (2004), 37(26), 9738-9745

This paper reports on the synthesis of a novel poly(ethylene oxide) (PEO) macromonomer, which can be copolymerized with epsilon-caprolactone (epsilon-CL) by ring-opening polymerization (ROP). PEO chains ... [more ▼]

This paper reports on the synthesis of a novel poly(ethylene oxide) (PEO) macromonomer, which can be copolymerized with epsilon-caprolactone (epsilon-CL) by ring-opening polymerization (ROP). PEO chains end-capped by an epsilon-caprolactone unit (gammaPEO(.)CL) have been synthesized by living anionic ring-opening polymerization of ethylene oxide (EO) initiated by the potassium alkoxide of 1,4-dioxaspiro[4.5]decan-8-ol, followed by derivatization of the acetal into a ketone and the Baeyer-Villiger oxidation of the ketone into a lactone. The end-capping of PEO by epsilon-CL was assessed by FTIR, MALDI-TOF, and H-1 NMR spectroscopy. This type of macromonomer is a precursor of amphiphilic comblike copolymers consisting of a biodegradable hydrophobic backbone of poly-(epsilon-caprolactone) (PCL) and hydrophilic PEO grafts. Copolymerization of gammaPEO(.)CL with epsilon-CL was successfully initiated by aluminum alkoxide. [less ▲]

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