Supramolecular Chemistry Polymers The Mayer Group is working in the area of design, preparation and application of nanoscale structures that feature construction by means of persistent mutual entanglement of smaller molecular-scale structures. Compounds that consist of many persistently entangled individual structures are also of interest since the properties of these assemblies can be tuned through variation of the proportion of the entangled component species. Examples of persistently entangled polymeric assemblies include polyrotaxanes, polycatenanes and daisy-chain polymers. Recently, the Mayer group developed a new approach to a stable entangled assembly that is composed of a molecular chain that was threaded through numerous molecular rings by a process known as an entropy-driven ring-opening olefin metathesis polymerization ED-ROMP.
Entropy-driven ring-opening olefin metathesis polymerizations of macrocycles by Zheng Xue; Michael F. From early proof-of-principle reports through current state-of-the-art studies with an inclination towards materials applications, the known examples of these uncommon polymerizations are surveyed.
The underpinnings of why these reactions work, what is and what is not to be expected and the prevailing practical measures to be taken to favor ED-ROMPs are discussed.
Kuhl; Roland Faller Molecular simulations and neutron reflectivity are both extremely valuable tools for determining the structure of soft matter at interfaces and under confinement.
The high resolution structural information provided by these techniques allows us to obtain a thorough understanding at the molecular level. Here we present examples of polymer thin films and show the advantages these two techniques offer and how we can combine the approaches in order to provide a complete structural and thermodynamic picture.
The initial formation of initiating sites for atom transfer radical polymerization ATRP on various polymer surfaces and numerous inorganic and metallic surfaces is elaborated.
The subsequent ATRP grafting of a multitude of monomers from such surfaces to generate thin covalently linked polymer coatings is discussed briefly in order to provide a readily accessible survey.
The potential for achieving a range of well-defined biofunctionalities, such as inhibition of non-specific fouling, immobilization of biomolecules, separation of proteins, adsorbents for proteins or cells, antibacterial activity, and encapsulation of drugs in particular provided by these surface-grafted polymers is described.
A block-copolymer hydrogel encapsulates bacteriorhodopsin and produces the longest photochromic response of the membrane protein under high water content conditions by Dewang Ma; Yingchun Zhao; Jia Wu; Ting Cui; Jiandong Ding Here we report, for the first time, that an amphiphilic block copolymer could surprisingly prolong the decay time of the M intermediate of bacteriorhodopsin BR upon excitation with light, as a demonstration that some synthetic polymers can significantly tune protein functions in a wet material.
Viscoelastic properties of confined polymer films measured via thermal wrinkling by Edwin P. Patton; Rui Huang; Christopher M.
We present a new wrinkling-based measurement technique for quantifying the viscoelastic properties of confined polymer thin films. This approach utilizes real-time laser-light scattering to observe the kinetics of thermally-induced surface wrinkling, which evolves isothermally as a function of annealing time.
Specifically, wrinkling is induced by applying a thermal stress to a polystyrene film that is sandwiched between a silicon substrate and an aluminium thin film superstrate.
By following the time evolution of the wrinkle wavelength and amplitude, we can infer the rubbery modulus and shear viscosity of the polystyrene film with the aid of a theoretical model. Amphiphilic micelles with waist cross-linked structure exhibit both core—shell reversing behavior and thermal sensitivity.
Effect of monomer structure on the gelation of a class of metallo-supramolecular polymers by Wengui Weng; Zheng Li; Alex.
Gelation of metallo-supramolecular polymers prepared from three ditopic ligand monomers, 1, 2 and 3, derived, respectively, from tetra- penta- and hexaethylene glycols, in the presence of the transition metal ion ZnII, as well as the properties of the resulting gels, are investigated and compared.
It is found that these slight changes in the core length of the monomer lead to substantial variations in the gel characteristics, which can be attributed to solubility differences between the corresponding metallo-supramolecular polymers.opening olefin metathesis polymerization of catenanes, and to show precise synthetic control over linear number of density of threaded macrocycles within polypseudorotaxanes via random ring-opening olefin metathesis polymerization.
lysts by Grubbs,7 the olefin metathesis reaction, including ring-opening metathesis polymerization (ROMP), 8–10 meets the requirements for high selectivity and functional group toler-.
The synthesis of cyclic polybutadienes using ring-opening metathesis polymerization (ROMP) was accomplished.
A cyclic Ru alkylidene catalyst, where a terminal ligand was covalently linked to the Ru alkylidene, was used to polymerize either 1,5-cyclooctadiene (COD) or 1,5,9-trans-cis-trans-cyclododecatriene (CDT).
Trace amounts of an acyclic impurity, 4-vinylcyclohexene, found in the COD . Metathesis polymerization of cystine-based macrocycles Metathesis polymerization of cystine-based Schlaad* Macrocycles based on L-cystine were synthesized by ring-closing metathesis (RCM) and subsequently polymerized by entropy-driven ring-opening metathesis polymerization (ED-ROMP).
Monomer. Recently, the Mayer group developed a new approach to a stable entangled assembly that is composed of a molecular chain that was threaded through numerous molecular rings by a process known as an entropy-driven ring-opening olefin metathesis polymerization (ED-ROMP).
In this manuscript, an entropy-driven ring-opening metathesis polymerization (ED-ROMP) approach is for the first time applied in producing a MCLCP by polymerizing a macrocyclic olefin monomer.