Browsing by Subject "Hydrogels"

Article

Cationic amphiphilic model networks: Synthesis by group transfer polymerization and characterization of the degree of swelling

Simmons, M. R.; Yamasaki, E. N.; Patrickios, Costas S. (2000)

Group transfer polymerization (GTP) was applied to prepare model networks based on 2-(dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate (MMA). The flexibility of GTP allowed the synthesis of three isomeric ...

Article

Cationic homopolymer model networks and star polymers: Synthesis by group transfer polymerization and characterization of the aqueous degree of swelling

Simmons, M. R.; Yamasaki, E. N.; Patrickios, Costas S. (2000)

A series of hydrophilic model networks based on homopolymers of a weak base were prepared using group transfer polymerization (GTP) and characterized in terms of their aqueous degree of swelling as a function of pH. This ...

Article

Covalent amphiphilic polymer networks

Patrickios, Costas S.; Georgiou, Theoni K. (2003)

The recent literature on chemically cross-linked amphiphilic polymer networks is reviewed. The main subjects covered are network synthesis, characterization, modeling and applications. Special mention is made to more modern ...

Article

Double-networks based on pH-responsive, amphiphilic "core-first" star first polymer conetworks prepared by sequential RAFT polymerization

Kitiri, E. N.; Patrickios, C. S.; Voutouri, C.; Stylianopoulos, T.; Hoffmann, I.; Schweins, R.; Gradzielski, M. (2017)

This manuscript presents the preparation and study of a new double-network hydrogel system, comprising an amphiphilic, pH-responsive first polymer conetwork synthesized via reversible addition-fragmentation chain transfer ...

Article

Double-networks based on pH-responsive, amphiphilic "core-first" star first polymer conetworks prepared by sequential RAFT polymerization

Kitiri, E. N.; Patrickios, Costas S.; Voutouri, Chrysovalantis; Stylianopoulos, Triantafyllos; Hoffmann, I.; Schweins, R.; Gradzielski, M. (2017)

This manuscript presents the preparation and study of a new double-network hydrogel system, comprising an amphiphilic, pH-responsive first polymer conetwork synthesized via reversible addition-fragmentation chain transfer ...

Article

Dynamic responses in nanocomposite hydrogels

Loizou, Elena; Butler, P.; Porcar, L.; Schmidt, G. (2006)

The shear response of a series of polymer-clay gels has been investigated by means of rheology and small-angle neutron scattering (SANS). The gels have the same composition by mass but different polymer molecular weights ...

Article

Fabrication and characterization of superparamagnetic and thermoresponsive hydrogels based on oleic-acid-coated Fe3O4 nanoparticles, hexa(ethylene glycol) methyl ether methacrylate and 2-(acetoacetoxy)ethyl methacrylate

Papaphilippou, P.; Pourgouris, A.; Marinica, O.; Taculescu, A.; Athanasopoulos, G. I.; Vekas, L.; Krasia-Christoforou, T. (2011)

Stimuli-responsive hydrogel nanocomposites comprised of swollen polymer networks, in which magnetic nanoparticles are embedded, are a relatively new class of "smart" soft materials presenting a significant impact on various ...

Article

Heterogeneity in nanocomposite hydrogels from poly(ethylene oxide) cross-linked with silicate nanoparticles

Schexnailder, P.; Loizou, Elena; Porcar, L.; Butler, P.; Schmidt, G. (2009)

We investigate the influence of ionic strength on the structural heterogeneity and viscoelastic properties of nanocomposite hydrogels. We use small-angle scattering and rheology to monitor structural changes as a function ...

Article

"Inverse polyampholyte" hydrogels from double-cationic hydrogels: Synthesis by RAFT polymerization and characterization

Pafiti, Kyriaki S.; Elladiou, Marios; Patrickios, Costas S. (2014)

We present two novel, homologous, pyridine-based monomers, 2-(pyridin-2-yl)ethyl methacrylate (PyEMA) and (pyridin-2-yl)methyl methacrylate (PyMMA), which, despite their structural similarity, the former can be readily ...

Article

Large scale structures in nanocomposite hydrogels

Loizou, Elena; Butler, P.; Porcar, L.; Kesselman, E.; Talmon, Y.; Dundigalla, A.; Schmidt, G. (2005)

The physical picture of the large scale structures in nanocomposite hydrogels and some of their unique behavior were discussed. The aqueous solutions of the synthetic hectorite type clay, Laponite RD (LRD) and poly(ethylene ...

Article

Polyelectrolytic amphiphilic model networks in water: A molecular thermodynamic theory for their microphase separation

Vamvakaki, Maria; Patrickios, Costas S. (2002)

The aqueous aggregation behavior of networks comprising hydrophilic ionic blocks and hydrophobic nonionic blocks was studied by formulating a molecular thermodynamic theory, which considers the Gibbs free energies of the ...

Article

Randomly cross-linked homopolymer networks: Synthesis by group transfer polymerization in solution and characterization of the aqueous degree of swelling

Hadjiyannakou, Stella C.; Yamasaki, E. N.; Patrickios, Costas S. (2001)

Randomly cross-linked homopolymer networks of 2-(dimethylamino)ethyl methacrylate (DMAEMA) of various average degrees of polymerization (DPs) between cross-links were synthesized by group transfer polymerization (GTP) in ...

Article

Regular and inverse polyampholyte hydrogels: A detailed comparison

Constantinou, Anna P.; Elladiou, Marios; Patrickios, Costas S. (2016)

Two series of polyampholyte (PA) hydrogels were prepared via reversible addition-fragmentation chain transfer polymerization, followed by removal of the protecting group of the acidic monomer repeating units (methacrylic ...

Article

Reversible hydrogels from amphiphilic polyelectrolyte model multiblock copolymers: The importance of macromolecular topology

Popescu, M. -T; Athanasoulias, I.; Tsitsilianis, C.; Hadjiantoniou, Natalie A.; Patrickios, Costas S. (2010)

The association ability of model amphiphilic polyelectrolytes with multi-block architecture, i.e. ABA, BABAB, ABABABA and BABABABAB (A hydrophobic, B polyelectrolyte block) was studied in aqueous media. The gelation ...

Article

Shear-induced nanometer and micrometer structural responses in nanocomposite hydrogels

Loizou, Elena; Porcar, L.; Schexnailder, P.; Schmidt, G.; Butler, P. (2010)

The structural responses of a polymer-clay nanocomposite hydrogel to an imposed shear field are investigated from the nanometer to the micrometer length scales. The effects of polymer molecular weight and concentration of ...

Article

Stimuli-Responsive amphiphilic polyelectrolyte heptablock copolymer physical hydrogels: An unusual ph-response

Popescu, M. -T; Tsitsilianis, C.; Papadakis, Christine M.; Adelsberger, J.; Balog, Sándor; Busch, P.; Hadjiantoniou, Natalie A.; Patrickios, Costas S. (2012)

An amphiphilic cationic polyelectrolyte based on poly[2-(dimethylamino) ethyl methacrylate] (polyDMA) and poly(n-butyl methacrylate) (polyBuMA) with a BuMA-DMA-BuMA-DMA-BuMA-DMA-BuMA heptablock copolymer architecture was ...

Article

Structural effects of crosslinking a biopolymer hydrogel derived from marine mussel adhesive protein

Loizou, Elena; Weisser, J. T.; Dundigalla, A.; Porcar, L.; Schmidt, G.; Wilker, J. J. (2006)

In an effort to explore new biocompatible substrates for biomedical technologies, we present a structural study on a crosslinked gelatinous protein extracted from marine mussels. Prior studies have shown the importance of ...

Article

Synthesis and characterization of amphiphilic cationic symmetrical ABCBA pentablock terpolymer networks: Effect of hydrophobic content

Triftaridou, Aggeliki I.; Loizou, Elena; Patrickios, Costas S. (2008)

Group transfer polymerization was employed for the preparation of six amphiphilic terpolymer networks comprising the hydrophilic, pH-responsive 2-(dime-thylamino)ethyl methacrylate (DMAEMA), the neutral hydrophilic methoxy ...

Article

Synthesis and characterization of three-component polyelectrolytic amphiphilic model networks

Hadjiantoniou, Natalie A.; Triftaridou, Aggeliki I.; Georgiou, Theoni K.; Patrickios, Costas S. (2005)

Two hydrophilic monomers, 2-(dimethylamino)ethyl methacrylate (DMAEMA, ionizable) and methoxy hexa(ethylene glycol) methacrylate (HEGMA, non-ionic), and one Hydrophobic monomer, n-butyl methacrylate (BuMA) were copolymerized ...

Article

Synthesis, characterization, and modeling of cationic amphiphilic model hydrogels: Effects of polymer composition and architecture

Triftaridou, Aggeliki I.; Hadjiyannakou, Stella C.; Vamvakaki, Maria; Patrickios, Costas S. (2002)

Group transfer polymerization (GTP) was used for the preparation of eight amphiphilic networks based on 2-(dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate (MMA). Seven of the networks had linear segments ...