TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from hydrogen-bonding monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Invited talk (Dr. Jean-Francois Lutz) Institut Charles Sadron CY - Strasbourg, France DA - 26.01.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - H bonds KW - Diaminopyridine KW - Acrylamide PY - 2018 AN - OPUS4-44001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Asadujjaman, Asad A1 - Espinosa de Oliveira, T. A1 - Mukherji, D. A1 - Bertin, Annabelle T1 - Polyacrylamide ‘‘revisited’’: UCST-type reversible thermoresponsive properties in aqueous alcoholic solutions N2 - Combining experiments and all-atom molecular dynamics simulations, we study the conformational behavior of polyacrylamide (PAM) in aqueous alcohol mixtures over a wide range of temperatures. This study Shows that even when the microscopic interaction is dictated by hydrogen bonding, unlike its counterparts that present a lower critical solution temperature (LCST), PAM shows a counterintuitive tunable upper critical solution temperature (UCST)-type phase transition in water/alcohol mixtures that was not reported before. The Phase transition temperature was found to be tunable between 4 and 60 1C by the type and concentration of alcohol in the mixture as well as by the solution concentration and molecular weight of the polymer. In addition, molecular dynamics simulations confirmed a UCST-like behaviour of the PAM in aqueous alcoholic solutions. Additionally, it was observed that the PAM is more swollen in pure alcohol solutions than in 80% alcoholic solutions due to y-like behaviour. Additionally, in the globular state, the size of the aggregates was found to increase with increasing solvent hydrophobicity and polymer concentration of the solutions. Above ist Phase transition temperature, PAM might be present as individual polymer chains in the coil state (r10 nm). As PAM is a widespread polymer in many biomedical applications (gel electrophoresis, etc.), this finding could be of high relevance for many more practical applications in high performance pharmaceuticals and/or sensors. KW - Thermoresponsive polymer KW - UCST-type polymer KW - Polyacrylamide KW - Water/alcohol mixtures PY - 2018 DO - https://doi.org/10.1039/c7sm02424j SN - 1744-6848 SN - 1744-683X VL - 14 IS - 8 SP - 1336 EP - 1343 PB - Royal Society of Chemistry CY - London AN - OPUS4-44002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from hydrogen-bonding monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Deutsche Physikalische Gesellschaft (DPG)-Frühjahrtagung 2018 CY - Berlin, Germany DA - 11.03.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - H bonds KW - Diaminopyridine KW - Acrylamide PY - 2018 AN - OPUS4-44569 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Dendritic Amphiphiles as Macromolecular Mimetics of Cellular Constituents N2 - One of the holy grails in chemistry is to reconstruct some of life’s functions within synthetic materials. In this contribution, we demonstrate that “simple” macromolecular architectures such as dendritic amphiphiles, Janus dendrimers, thermoresponsive and hybrid organic-inorganic (co)polymers enable to mimic some of the functions of proteins for biomineralization, natural bactericides, biological membranes or the stimuli-responsive cytoskeleton. T2 - Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) - Dpt. des Matériaux Organiques (DMO), invited talk by Prof. Laurent Douce CY - Strasbourg, France DA - 09.02.2018 KW - Dendritic amphiphile KW - Antibacterial properties KW - Vesicles KW - Microfluidic PY - 2018 AN - OPUS4-44146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Controlled self-assembly of Janus dendrimers via microfluidics N2 - Vesicles self-assembled in water from natural and synthetic phospholipids (liposomes), amphiphilic block copolymers (polymersomes), and more recently amphiphilic Janus dendrimers (dendrimersomes) -5 as hollow soft structures in the nano size regime have attracted increasing interest as they can mimic primitive and contemporary biological membranes, and can be configured into biomimetic nanocapsules with application in nanomedicine such as gene, proteins and drug carriers or theranostics. Compared to other amphiphilic structures, the molecular structure of Janus dendrimers can be precisely controlled: by using the vast range of tools from organic chemistry their size, architecture, density, generation as well as the number of end groups of the individual dendrons can be modified as desired. Unfortunately, the controlled production of supramolecular aggregates made thereof is still a challenging task. Conventional batch-based techniques such as the solvent injection method or the film hydration method typically go along with a lack of control over self assembly/mixing and thus over size, morphology and size distribution of the vesicles. The micromixer technology is a promising method for the controlled preparation of supramolecular assemblies as it allows control of mixing at microscale level. In addition, such microfluidic systems benefit from a high mixing efficiency, a low mixing time as well as from a reproducible and continuous production of soft nanoparticles. Herein, we report on the microfluidic-controlled self-assembly of Janus dendrimers as dendrimersomes and the impact of the mixing parameters on the self-assembly process. T2 - Invited talk Leibniz Institute of Polymer Research Dresden (IPF) CY - Dresden, Germany DA - 08.03.2018 KW - Vesicles KW - Janus dendrimers KW - Microfluidics PY - 2018 AN - OPUS4-44441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Building macromolecular mimetics of cell constituents N2 - One of the holy grails in chemistry is to reconstitute some of life’s functions with or within synthetic materials. In this contribution, we demonstrate that “simple” macromolecular architectures such as dendritic amphiphiles, Janus dendrimers, thermoresponsive and hybrid organic-inorganic (co)polymers enable to mimic some of the functions of proteins for biomineralization, natural bactericides, biological membranes or the stimuli-responsive cytoskeleton. T2 - Chemiedozententagung 2018 CY - Jena, Germany DA - 05.03.2018 KW - UCST-type polymers KW - Bioinspiration KW - Thermoresponsive polymers PY - 2018 AN - OPUS4-44442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Building macromolecular mimetics of cell constituents N2 - One of the holy grails in chemistry is to reconstruct some of life’s functions with synthetic materials. In this contribution, we demonstrate that “simple” macromolecular architectures such as dendritic amphiphiles, Janus dendrimers, thermoresponsive and hybrid organic-inorganic (co)polymers enable to mimic some of the functions of proteins for biomineralization, natural bactericides, biological membranes or the stimuli-responsive cytoskeleton. T2 - Makromolekulares Kolloquium Freiburg 2018 CY - Freiburg in Breisgau, Germany DA - 21.02.2018 KW - Thermoresponsive polymers KW - Cytoskeleton mimic PY - 2018 AN - OPUS4-44296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from hydrogen-bonding monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Séminaire Laboratoire de Chimie des Polymères (LCP), UPMC, Paris CY - Paris, France DA - 28.09.2017 KW - UCST-type polymers KW - H-bonding monomers PY - 2017 AN - OPUS4-42478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Controlled self-assembly of Janus dendrimers via microfluidics N2 - Vesicles self-assembled in water from natural and synthetic phospholipids (liposomes), amphiphilic block copolymers (polymersomes), and more recently amphiphilic Janus dendrimers (dendrimersomes) -5 as hollow soft structures in the nano size regime have attracted increasing interest as they can mimic primitive and contemporary biological membranes, and can be configured into biomimetic nanocapsules with application in nanomedicine such as gene, proteins and drug carriers or theranostics. Compared to other amphiphilic structures, the molecular structure of Janus dendrimers can be precisely controlled: by using the vast range of tools from organic chemistry their size, architecture, density, generation as well as the number of end groups of the individual dendrons can be modified as desired. Unfortunately, the controlled production of the supramolecular aggregates made thereof is still a challenging task. Conventional batch-based techniques such as the solvent injection method or the film hydration method typically go along with a lack of control over mixing and thus over size, morphology and size distribution. The micromixer technology is a promising method for the controlled preparation of supramolecular assemblies as it allows control of mixing at microscale level. In addition, such microfluidic systems benefit from a high mixing efficiency, a low mixing time as well as from a reproducible and continuous synthesis. Herein, we report on the microfluidic-controlled self-assembly of Janus dendrimers as dendrimersomes and the impact of the mixing parameters on the self-assembly process. T2 - 11th Young Scientists' Workshop, Fraunhofer ICT-IMM CY - Mainz, Germany DA - 27.09.2017 KW - Vesicles KW - Dendrimersomes KW - Micromixer PY - 2017 AN - OPUS4-42479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from hydrogen-bonding monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - UCT&IOCB Theoretical Chemistry Seminars CY - University of Chemistry and Technology, Department of Physical Chemistry, Prague, Czech Republic DA - 24.11.2017 KW - Thermoresponsive polymers KW - UCST polymers KW - 2,6-diaminopyridine PY - 2017 AN - OPUS4-43129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from monomers with hydrogen-bonding interactions N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media with applications in the field of drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and/or 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - 7. Jahrestreffen der Seniorexperten Chemie CY - Weimar, Germany DA - 02.05.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - Polyacrylamide KW - Water/alcohol mixtures PY - 2018 AN - OPUS4-44845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper Critical Solution Temperature (UCST)-type Thermoresponsive Polymers from Hydrogen-Bonding Monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications,but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or Ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and/or 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Bordeaux Polymer Conference BPC 2018 CY - Bodeaux, France DA - 28.05.2018 KW - Acrylamide KW - Thermoresponsive polymer KW - UCST-type polymer KW - H-bonds KW - Diaminopyridine PY - 2018 AN - OPUS4-45155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from monomers with hydrogen-bonding interactions N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the appropriate side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and/or 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Invited Talk (Prof. Christine Papadakis) Technische Universität München - Soft Matter Physics CY - Munich, Germany DA - 03.07.2018 KW - Thermoresponsive polymer KW - UCST-type polymer KW - H bonds KW - Diaminopyridine KW - Acrylamide PY - 2018 AN - OPUS4-45423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper critical solution temperature (UCST)-type thermoresponsive polymers from acrylamide-based monomers N2 - UCST-type thermoresponsive polymers (i.e. that phase separate from solution upon cooling) present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel non-ionic UCST-type polymers because of their hydrophilic nature (with the right side chain) and propensity to form hydrogen bonds. We will present our latest results on the UCST-type thermoresponsive behaviour of acrylamide- and 2,6-diaminopyridine-based homopolymers and copolymers in water or water/alcohol mixtures, and give some insights about the rational design of UCST polymers relying on H-bonding. T2 - Bioorganik 2017 – 26th Symposium "Bioorganic Chemistry" for young researchers CY - Berlin, Germany DA - 20.09.2017 KW - Thermoresponsive polymers KW - UCST polymers KW - 2,6-diaminopyridine KW - Acrylamide PY - 2017 AN - OPUS4-42007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bertin, Annabelle T1 - Polyelectrolyte complexes of DNA and polycations as gene delivery vectors N2 - This review gives representative examples of the various types of synthetic cationic polymers or polyampholytes (chemical structure, architecture, etc) that can be used to complex DNA (forming polyplexes) for their application in gene delivery. In designing polycations for gene delivery, one has to take into account a balance between protection of DNA versus loss of efficiency for DNA condensation and efficient condensation versus hindering of DNA release. Indeed, if the polyplexes are not stable enough, premature dissociation will occur before delivery of the genetic material at the desired place, resulting in low transfection efficiency; on the other hand, a complex that is too stable will not release the DNA, also resulting in low gene expression. The techniques generally used to determine these properties are gel electrophoresis to test the DNA/polymer complexation, ethidium bromide or polyanion displacement to test the affinity of a polymer for DNA, and light scattering to determine the extent of DNA condensation. Moreover, with the development of more precise instruments for physico-chemical characterization and appropriate biochemical and biophysical techniques, a direct link between the physico-chemical characteristics of the polyplexes and their in vitro and in vivo properties can be drawn, thus allowing tremendous progress in the quest towards application of polyplexes for gene therapy, beyond the research laboratory. KW - Colloidal stabilization KW - DNA KW - Gene delivery vectors KW - Polyampholytes KW - Polycations KW - Polyelectrolyte complexes KW - Polyplexes PY - 2014 SN - 978-3-642-40745-1 SN - 978-3-642-40746-8 DO - https://doi.org/10.1007/12_2013_218 N1 - Serientitel: Advances in polymer science – Series title: Advances in polymer science VL - 256 SP - 103 EP - 195 PB - Springer AN - OPUS4-30060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Asadujjaman, Asad A1 - Bertin, Annabelle A1 - Schönhals, Andreas T1 - Dielectric analysis of the upper critical solution temperature behaviour of a poly(acrylamide-coacrylonitrile) copolymer system in water N2 - A copolymer consisting of acrylamide (AAm) and acrylonitrile (AN) in aqueous solution was investigated using broadband dielectric spectroscopy at frequencies between 10⁻¹ Hz and 10⁶ Hz in the temperature range from 2 °C to 60 °C. This system shows an UCST phase behavior. The phase transition and aggregation behavior is monitored by both the temperature and frequency dependence of the complex conductivity σ*(f, T), where the AN fraction and the concentration of the solution were varied. Additionally, the dielectric data are compared with the results obtained from dynamic light scattering measurements. The temperature dependence of the DC conductivity (σDC) of the copolymer solution is monitored and the phase transition temperature (PTT) of the poly(AAm-co-AN) copolymer is deduced from a change in the T-dependence of the DC conductivity. The change in σDC can be explained by decreased effective charge carrier mobility and a reduction of the effective charge number density at temperatures below the phase Transition temperature of the poly(AAm-co-AN) solution. A pronounced interfacial polarization effect on the frequency dependence of the real part of the conductivity (σ') is observed at temperatures below the phase Transition temperature. The charge carriers are blocked at the formed aggregates giving rise to this interfacial polarization. The dependence of the interfacial polarization on the acrylonitrile fraction in the copolymer and the concentration of the solution is studied in detail and conclusions concerning the internal structures of the copolymer aggregates are drawn. KW - Thermoresponsive polymres PY - 2017 DO - https://doi.org/10.1039/c6sm02684b SN - 1744-6848 SN - 1744-683X VL - 13 IS - 12 SP - 2384 EP - 2393 PB - Royl Society of Chemistry Publishing AN - OPUS4-39556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Asadujjaman, Asad A1 - Ahmadi, Vahid A1 - Yalcin, M. A1 - ten Brummelhuis, N. A1 - Bertin, Annabelle T1 - Thermoresponsive functional polymers based on 2,6-diaminopyridine motif with tunable UCST behaviour in water/alcohol mixtures N2 - 2,6-Diaminopyridine based functional polymers poly N-(6-aminopyridin-2-yl)acrylamide) (PNAPAAm) and poly(N-(6-acetamidopyridin-2-yl)acrylamide) (PNAcAPAAm) were synthesized via free radical polymerization and in addition PNAcAPAAm was synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization for comparison. The obtained polymers displayed upper critical solution temperature (UCST)-type reversible thermoresponsiveness in water/alcohol mixtures. The UCST Phase transition behaviour of the obtained functional polymers was studied using temperature dependent turbidimetry, dynamic light scattering and 1H-NMR measurements. The phase transition temperature of the polymers was tunable by varying either the concentration of the polymer solution, the nature of the alcohol or the composition of the solvent mixture. The cloud Point temperature of PNAcAPAAm was found to decrease with increasing alcohol content (MeOH, EtOH and iPrOH) in water/alcohol mixtures. Past a critical amount of EtOH or iPrOH in water, the cloud point temperature of PNAcAPAAm increased upon further addition of EtOH or iPrOH. Such functional polymers with tunable UCST behaviour can be applicable in drug delivery, sensing, personal care and microfluidic applications. KW - UCST polymer KW - 2,6-diaminopyridine KW - Cosolvency PY - 2017 DO - https://doi.org/10.1039/c7py00539c SN - 1759-9954 SN - 1759-9962 VL - 8 IS - 20 SP - 3140 EP - 3153 PB - RSC AN - OPUS4-40417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Upper Critical Solution Temperature (UCST)-type thermoresponsive polymers from acrylamide-based monomers N2 - UCST-type thermoresponsive polymers that phase separate from solution upon cooling present a tremendous potential not only in aqueous media where they can be used in drug delivery, diagnostic and microfluidic applications, but also in water/alcohol mixtures, where they can be used for instance in sensing systems for alcohol-soluble drugs. However, only a few thermoresponsive polymers have been reported that present an UCST in a relevant temperature range and “green” solvents such as water or ethanol. In this context, acrylamide-based monomers can be very useful building blocks for designing novel UCST-type polymers because of their hydrophilic nature (with the right side chain) and propensity to form hydrogen bonds. We want to present our latest results on the copolymer poly(acrylamide-co-acrylonitrile) (P(AAm-co-AN)) that present a UCST in water as well as on two homopolymers based on an acrylamide derivative of 2,6-diaminopyridine, namely poly(N-(6-aminopyridin-2-yl)acrylamide) (PNAPAAm) and poly(N-(6-acetamidopyridin-2-yl)acrylamide) (PNAcAPAAm) that show UCST-type thermoresponsiveness in water/alcohol mixtures. Our focus for P(AAm-co-AN)) is its aggregation behaviour above and below its phase transition temperature as the size of thermoresponsive polymeric systems is of prime importance for biomedical applications (as size dependent processes take place in the body) and is linked to the optical properties of a material that matter in materials science. In the case of PNAPAAm and PNAcAPAAm, we focused on the co-solvency/co-non solvency effect on the phase transition temperature in water/alcohol mixture. Indeed, polymers with UCST behavior below 60°C in water/alcohol mixtures are extremely promising for the preparation of “smart” materials for sensing. T2 - Soft smart responsive materials workshop: Fundamentals and applications (SmartCECAM) CY - Mainz, Germany DA - 11.05.2017 KW - Thermoresponsive polymers KW - UCST-type polymers KW - poly(acrylamide-co-acrylonitrile) KW - 2,6-diaminopyridine-based polymers KW - co-solvency in water/acohol mixture PY - 2017 AN - OPUS4-40211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Bioinspired hybrid organic-inorganic copolymers N2 - The demand for high-performance materials has strongly increased over the last decade. One way to improve their performance is to introduce material gradients as found in Nature (for example squid beaks, spider fangs, mussel byssal threads). One path towards the achievement of such material gradients is the synthesis of hybrid (gradient) copolymers, for instance based on silane and organic monomers. Since not all gradient copolymers can be synthesized by utilising the reactivity ratios of the monomers, forced gradients have to be used. However, in order to obtain gradient copolymers at high conversions, living or pseudo-living copolymerizations have to be performed and so far only few hybrid (organic / inorganic) gradient copolymers have been reported. In this contribution we will present the synthesis of a novel organic / inorganic hybrid copolymer via controlled radical polymerization. T2 - 5th International Conference on Multifunctional, Hybrid and Nanomaterials CY - Lisbon, Portugal DA - 06.03.2017 KW - Hybrid organic-inorganic copolymers KW - RAFT polymerization KW - ATRP polymerization PY - 2017 AN - OPUS4-39464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Temperature Sensitive Aggregation Behavior of Poly(Acrylamide-co-Acrylonitrile) in Water N2 - Thermoresponsive polymers have shown great potential in applications such as bioseparation, drug delivery and diagnostic. Only few thermoresponsive polymers that present an upper critical solution temperature (UCST), i.e. phase separate from solution upon cooling, in a relevant temperature range have been reported so far. Herein, a robust UCST-type copolymer of acrylamide (AAm) and acrylonitrile (AN) (poly(AAm-co-AN)) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization and its thermo-induced aggregation behavior in aqueous media was studied. We propose a model for the temperature-induced aggregation behaviour of UCST-type poly(AAm-co-AN) copolymer in aqueous solution on the basis of turbidity measurements, SLS, DLS, SANS and cryo-TEM. T2 - German Physical Society - Spring Meeting 2017 CY - Dresden, Germany DA - 19.03.2017 KW - Thermoresponsive polymers KW - UCST-type copolymer PY - 2017 AN - OPUS4-39465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Functional polymer based on 2,6-diaminopyridine with tunable UCST behaviour in water/alcohol mixture N2 - Thermoresponsive polymers are of great importance in numerous applications such as bioseparation, drug delivery, diagnostic and microfluidic applications. Only few thermoresponsive polymers that present an upper critical solution temperature (UCST), i.e. phase separate from solution upon cooling, in a relevant temperature range and green solvents such as water or ethanol have been reported. Indeed, polymers with UCST behavior below 60°C in alcohol or water/alcohol mixtures are extremely promising for the preparation of smart materials for sensing. In this work two novel functional polymers of based on a 2,6-diaminopyridine motif were synthesized by free radical polymerization. Their UCST-type transition temperature is tunable by varying either their concentration in solution or the type of solvent. Insights into this phenomenon will be given based on turbidimetry and temperature dependent dynamic light scattering T2 - German Physical Society - Spring Meeting 2017 CY - Dresden, Germany DA - 19.03.2017 KW - Thermoresponsive polymers KW - USCT-type polymers KW - Polymers based on 2,6-diaminopyridine PY - 2017 AN - OPUS4-39466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Phase transition and aggregation behavior of thermoresponsive copolymer poly(acrylamide-co-acrylonitrile) N2 - Thermoresponsive polymers have shown great potential in applications such as bioseparation, drug delivery and diagnostic. Only few thermoresponsive polymers that present an upper critical solution temperature (UCST), i.e. phase separate from solution upon cooling, in a relevant temperature range have been reported so far. Moreover, the most studied UCST type polymers namely polybetaines are difficult to use under physiological conditions, which significantly restricts their potential applications. Therefore, UCST polymers with sharp and robust phase transition in physiological conditions (in the presence of salts, etc.) are highly needed in order to extend the range of applications of this class of polymers. A robust UCST-type copolymer of acrylamide (AAm) and acrylonitrile (AN) (poly(AAm-co-AN)) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization and its thermo-induced aggregation behavior in aqueous media was studied by turbidimetry, dynamic and static light scattering. At temperature below the UCST, the poly(AAm-co-AN) copolymer chains were aggregated together. The aggregate size was found to be larger with increasing AN contents and became smaller upon dilution of the copolymer solutions. While above the UCST, the poly(AAm-co-AN) copolymer chains were expanded and weekly associated in solution. The association between the copolymer chains formed smaller aggregates with increasing the AN contents or the concentration of the solutions. A model is proposed to explain such association-aggregation behavior of the poly(AAm-co-AN) copolymer depending on the AN contents and concentration of the solutions. T2 - Biennial meeting GDCh-Division of Macromolecular Chemistry CY - Halle, Germany DA - 11.09.2016 KW - Thermoresponsive polymers PY - 2016 AN - OPUS4-37365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Phase transition and aggregation behavior of thermoresponsive copolymer Poly(acrylamide-co-acrylonitrile) N2 - The results of a study on the phase transition and aggregation behavior of the thermoresponsive copolymer Poly(acrylamide-co-acrylonitrile) are presented. T2 - Warwick Polymer Conference 2016 CY - Warwick, England DA - 11.07.2016 KW - Thermoresponsive polymers PY - 2016 AN - OPUS4-37366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Controlled self-assembly of dendritic amphiphiles in micromixers N2 - The controlled synthesis of supramolecular aggregates formed by the self-assembly of dendritic amphiphiles is a challenging task. Conventional batch-based techniques such as the solvent injection method or the film hydration method typically go along with a lack of control over mixing and thus over size, morphology and size distribution. The micromixer technology is a promising method for the controlled preparation of supramolecular assemblies as it allows control of mixing at microscale level. In addition, such microfluidic systems benefit from a high mixing efficiency, a low mixing time as well as from a reproducible and continuous synthesis. Herein, we report on the microfluidic-controlled self-assembly of several dendritic amphiphiles and the impact of the mixing parameters on the self-assembly process. T2 - 251st American Chemical Society National Meeting CY - San Diego, USA DA - 13.03.2016 KW - Dendritic amphiphiles KW - Self-assembly KW - Micromixer PY - 2016 AN - OPUS4-37371 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -