One-pot synthesis of network supported catalyst using supramolecular gel as template

A simple and general strategy is described for preparing network supported catalyst through a one-pot synthetic procedure using supramolecular gel as template.This procedure directly attaches ligand to support during fabricating the support.Using this strategy,supported CuBr/di-（2-picolyl） amine catalyst with U-shaped fibrillar network was prepared and used in atom transfer radical polymerization of methyl methacrylate.XPS and SEM characterization of the catalyst revealed homogeneous distribution of ligand,sufficient reactive sites,adequate mechanical strength and macroporosity.The polymerization results demonstrated high activity and reusability of such catalyst.This strategy might be extended to other supported catalysts used in column reactors.

Investigation on the Structure and Curing Performances of Secondary Amine Terminated Hyperbranched Poly(ester-amine)s

Three secondary amine terminated hyperbranched poly（ester-amine）s （defined as HPEA1, HPEA2 and HPEA3） were synthesized from piperazine （A2） and trimethylolpropane triacrylate （TMPTA, B3） at their molar ratios of 2.5：1, 2.25：1 and 2.0：1, respectively. The polymers were analyzed by 1H NMR, GPC, DSC and TGA. The results indicated that the ratio of secondary amine to tertiary amine and the content of secondary amine decreased, while the molecular weight, molecular weight distribution and glass transition temperature （Tg） increased from HPEA1 to HPEA3. Due to their reactive terminal groups and flexible chains, these polymers further reacted with an epoxy resin （E51） to form cured films under ambient conditions. With increasing the ratio between secondary amine groups and epoxy groups from 1：2 to 2：1, the gel content, film hardness and onset decomposing temperature of the cured samples increased. The good film performances should make the polymers as the components of non-solvent coating materials.

Assembling and releasing performance of supramolecular hydrogels formed from simple drug molecule as the hydrogelator

A simple drug compound, 4-oxo-4-（2-pyridinylamino） butanoic acid （defined as AP）, was able to gel water at 4 wt% concentration under various conditions. In the superstructure, AP molecules assembled into fibrous aggregates driving by hydrogen bonds and π-π stacking interaction. The gels with different backbone structures released drug molecules in different speeds.

Investigation on the Crystal Structure of Substituted Pyridine Based Organic Salt as the Low Molecular Weight Gelator

In order to define the chemical conformation of gelator,para-hydroxy pyridinium salt of 1,2,4,5-benzene tetracarboxylic acid（defined as G1）,four model compounds were prepared from para-,meta-,ortho-phthalic acid with 4-hydroxy pyridine（PHP）,and 1,2,4,5-benzene tetracarboxylic acid（BTA） with 4-pyridylcarbinol（PCB）,and their 1H NMR spectra were investigated.The single crystal of G1 obtained directly from gelling solvent was measured,which displayed complicated hydrogen-bonded networks arising from the supramolecular synthons and other weak interactions between H20 and the components. The powder X-ray diffraction （XRPD） experiments were also carded out to understand the relationship between molecular packing of the bulk crystal and the gelation behavior.

Influence of gelator structures on formation and stability of supramolecular hydrogels

A supramolecular hydrogel （defined as G1） formed from 1,2,4,5-benzene tetracarboxylic acid （BTCA） and 2-amino-3- hydroxypyridine possessed higher Tgel than that of another hydrogel （defined as G2） formed from BTCA and 3-hydroxypyridine. Based on the analysis of their xerogels by 1H NMR, IR and XRD, the higher stability of G1 was attributed to the formation of stronger hydrogen binding enhanced by the ortho amino group of 2-amino-3-hydroxypyridine.

Novel hot-melting hyperbranched poly(ester-amine) bearing self-complementary quadruple hydrogen bonding units

Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-melting materials.

Highly stable supramolecular hydrogels formed from 1,3,5-benzenetricarboxylic acid and hydroxyl pyridines

New supramolecular hydrogels with the maximal sol-gel transition temperature （Tgel） of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid （BTA） and para-hydroxyl pyridine （PHP） or meta-hydroxyl pyridine （MHP）. The single crystal structure of the complex formed from BTA and ortho-hydroxyl pyridine （OHP） indicated that the molecules assembled into superstructure via both hydrogen bonds and π--π stacking interaction.

Coordinated organogel templated fabrication of silver/polypyrrole composite nanowires

A new method to fabricate metal/conducting polymer composite nanowires is presented by taking silver/polypyrrole composite nanowires as an example. A silver （D-coordinated organogel as template was prepared firstly, and redox-polymerization of pyrrole took place on the gel fiber, giving product of silver/polypyrrole nanowires. The silver/polypyrrole nanowires were characterized by multiple techniques. This strategy could be carried out in one-step procedure at room temperature, and it proves the utility of coordinated organogels in template synthesis of polymer nanostructures.

CONTROLLED FABRICATION OF ONE-DIMENSIONAL POLYMER NANOSTRUCTURES via METALLOGEL TEMPLATE POLYMERIZATION

A facile method is reported to controllably fabricate one dimensional （1D） polymer nan,astructures via metallogel template polymerization. The metallogel was prepared through coordination interactions between silver ions and a ligand （L） bearing three pyridyl groups in tetrahydrofuran （THF）. The diameters of the metallogel nanofibers could be tuned by the gel concentration （GC）. Due to its high thermal stability and facility of removal, the metallogel was used as the template for radical polymerization of diacryolyl-2,6-diaminopyridine （DADAP） to form poly-diacryolyl-2,6-diaminopyridine （PDADAP） nanostructures. The gradually eroding of the templates by PDADAP provided us an effective way to fabricate various nanostructures of the polymer. We have demonstrated that different 1D nanostructures, including n^noribbons, nanotubes and nanowires, could be selectively fabricated by adjusting polymerization time, monomer concentration and GC. The rheological properties of the gel samples were tested by a rheometer. As prolonging the reaction time, more and more polymers were formed and the strength of the resulting polymer gels became higher and higher. The simple preparation process, easy controlled microstructures and adequate gel strength would make it a facile synthetic method for different 1D polymer nanosturctures.

New Hydrogen Bonded Supramolecular Hydrogels Formed through Gelating Two Isomeric Building Units Simultaneously

New hydrogen bonded supramolecular hydrogels were formed through simultaneously gelating two isomeric building units, 4-oxo-4-（2-pyridinylamino）butanoic acid （G1） and 4-oxo-4-（3-pyridinylamino）butanoic acid （G2） at various molar ratios in water.

Improving Anti-frosting Performance for Super-hydrophobic Nanocomposite Coatings

New super-hydrophobic nanocomposite coatings were formed from modified nano-sized CaCO3 particles and polyacrylate at weight ratio of 9/1-8/2. SEM and XPS analysis indicated that such hydrophobicity could be attributed to the surface nano-microstructure and the surface enrichment of fluorine atoms. As the surface hydrophobicity increased, longer time was required for formation the initial frost, which makes super-hydrophobic coatings suitable for anti-frosting purpose.