31 research outputs found
ChemMend: A Card Game To Introduce and Explore the Periodic Table while Engaging Studentsâ Interest
The deeply knowledge of the periodic table is one of the most important keys to understand
the basic principles of Chemistry. Memorizing the elements of the groups and periods is one of the most
commonly used strategies to learn the position of each element in the periodic table; nevertheless it is a hard
task for most students. The use of card games can represent a useful alternative to teach some chemical aspects. Here, we present ChemMend, a new Chemical card game which will allow chemistry students to obtain a good ability in the periodic table. This game attracts the attention of the students, and it allows them to
review mentally the period and group while playing; being the learning a consequence of the game. The
ChemMend game will introduce and explore the periodic table in the classroom
Pseudopeptidic Compounds for Biocompatible Gels: A Review
Simple pseudopeptides derived from natural amino
acids can be designed and prepared as efficient
gelators for a variety of solvents, and with a high
potential for biocompatibility. The appropriate
selection of structural components, reviewed herein,
shows how to produce gels with tailored properties,
including high thermal stability
Solvent Molding of Organic Morphologies Made of Supramolecular Chiral Polymers
12sihe self-assembly and self-organization behavior of uracil-conjugated enantiopure (R)- or (S)-1,1'-binaphthyl-2,2'-diol (BINOL) and a hydrophobic oligo(p-phenylene ethynylene) (OPE) chromophore exposing 2,6-di(acetylamino)pyridine termini are reported. Systematic spectroscopic (UVvis, CD, fluorescence, NMR, and SAXS) and microscopic studies (TEM and AFM) showed that BINOL and OPE compounds undergo triple H-bonding recognition, generating different organic nanostructures in solution. Depending on the solvophobic properties of the liquid media (toluene, CHCl3, CHCl3/CHX, and CHX/THF), spherical, rod-like, fibrous, and helical morphologies were obtained, with the latter being the only nanostructures expressing chirality at the microscopic level. SAXS analysis combined with molecular modeling simulations showed that the helical superstructures are composed of dimeric double-cable tape-like structures that, in turn, are supercoiled at the microscale. This behavior is interpreted as a consequence of an interplay among the degree of association of the H-bonded recognition, the vapor pressure of the solvent, and the solvophobic/solvophilic character of the supramolecular adducts in the different solutions under static and dynamic conditions, namely solvent evaporation conditions at room temperature.partially_openopenÄorÄeviÄ, Luka; Marangoni, Tomas; MiletiÄ, Tanja; Rubio-Magnieto, Jenifer; Mohanraj, John; Amenitsch, Heinz; Pasini, Dario; Liaros, Nikos; Couris, Stelios; Armaroli, Nicola; Surin, Mathieu; Bonifazi, DavideÄorÄeviÄ, Luka; Marangoni, Tomas; Miletic, Tanja; Rubio Magnieto, Jenifer; Mohanraj, John; Amenitsch, Heinz; Pasini, Dario; Liaros, Nikos; Couris, Stelios; Armaroli, Nicola; Surin, Mathieu; Bonifazi, David
A minimalistic catalytically-active cell mimetic made of a supra-molecular hydrogel encapsulated into a polymersome
A minimalistic multicomponent cell mimetic is described consisting of a fibrillar network formed by the self-assembly of a low molecular weight compound (cytoskeleton-like) that is entrapped into a polymersome (membrane-like), namely a jelly-polymersome. A simple imidazole-appended hydrogelator is used in order to obtain a catalytic nanoreactor able to hydrolyze an ester within the compartment in its self-assembled state
Self-assembled hybrid hydrogels based on an amphipathic low molecular weight peptide derivative and a water-soluble poly(para-phenylene vinylene)
The self-assembly of an amphipathic low molecular weight peptide and a water-soluble p-conjugated
polyelectrolyte is studied in order to form hybrid hydrogel materials with synergistic properties. The
self-assembly of the complex yields a network of one-dimensional fibrils, with enhanced fluorescence of
the p-conjugated polyelectrolyte in the hydrogel form. These hybrid hydrogels are also tested to study
the kinetics of release of a molecular dye.The authors thank the Cost Action CM 1304 (Emergence and
Evolution of Complex Chemical Systems) for a Short Term
Scientic Missions (STSM) of M. T.-S. in Mons. Research in
Mons is supported by the Science Policy Office of the Belgian
Federal Government (BELSPO â PAI 7/05). This work was also
supported by the Fonds de la Recherche Scientique â FNRS
under the under the grants n 1.B333.15F (CHIRNATES) and
n F.4532.16 (MIS-SHERPA). J. R.-M. is FNRS post-doctoral
researcher and M. S. is FNRS research associate. This work
was also supported by the Ministry of Economy and Competitiveness
of Spain (Grant CTQ2012-37735) and Universitat Jaume
I (Grant P1-1B2013-57). M. T.-S. thanks the Ministry of Education,
Culture and Sport of Spain for an FPU fellowship
Enzymatic probing of model lipid membranes : phospholipase A2 activity toward monolayers modified by oxicam NSAIDs
Stimulus responsive self-assembly of Gemini Amphiphilic Pseudopeptides
Amphiphilic amino acid derived compounds are very interesting for the design of building blocks able
to self-assemble into highly ordered nanostructures, in a hierarchical and controlled fashion. With this
aim, the modular synthesis and the full characterization of simple Gemini Amphiphilic Pseudopeptides
(GAPs) have been carried out. These compounds were designed to establish intermolecular interactions
in a hierarchical way to finally render supramolecular assemblies into well-ordered nanostructures,
such as fibers, tubes, tapes or spherical vesicles. Different structural variables have been implemented,
such as the amino acid side chain, the length of the central spacer and the nature of the hydrophobic
tails. Besides, the effect of the environment was systematically checked, by performing the studies in
solvents of different polarities (chloroform, methanol or aqueous methanol) and at different pHs
(neutral, basic and acidic). The non-covalent self-assembling abilities and the structural features of the
GAPs have been studied in the solid (SEM, TEM and FT-IR) and in the solution states (NMR, UV,
CD, FT-IR and fluorescence spectroscopy). Moreover, the connection between the solution and the
solid states has been established by monitoring the slow evaporation of the solvent by ATR FT-IR.
This study has allowed the establishment of a relationship between the chemical structures of the GAPs
and their abilities to form nanostructures. In some optimal cases (especially for the valine derivatives
with medium-length spacers and two decyloxybenzyl hydrophobic tails), they behaved as stimulus
responsive self-assembling nano-structures, which form amorphous materials from non-polar solvents,
nano-fibers from polar environments at neutral or basic pH and vesicles when become protonated at
acidic pH values. A reasonable structural model to explain the experimental observations can be
proposed through the combination of the results from the different techniques
Synthesis and organogelating ability of bis-urea pseudopeptidic compounds
A large family of amphiphilic pseudopeptidic derivatives in which the aliphatic tails are connected to the pseudopeptidic moiety through urea functionalities have been prepared with excellent yields. The synthetic procedure is simple and very efficient and allows a modular variation of a large number of structural parameters. The self-assembling properties of the resulting compounds has been studied under different conditions and using different media. Very interestingly, many of the compounds obtained have revealed to act as very efficient organogelators at low concentrations. The resulting gels provide some unusual properties. Of particular relevance are the broad scope of organic solvents that can be gelated and the high thermal stability of the resulting gels. Gels that are stable up to temperatures close to 100 °C can be obtained in some instances