Showing papers by "Samuel I. Stupp published in 2000"
TL;DR: A diblock coil with diphenylaminophenyl side chains, oligoethylene oxide segments, and a rigid molecular pentamer of phenylene vinylene are present in the molecule studied in this article.
Abstract: A diblock coil with diphenylaminophenyl side chains, oligoethylene oxide segments, and a rigid molecular pentamer of phenylene vinylene are present in the molecule studied here (see formula). When films of this material were investigated, the material was found to organize into nanostructures 12 nm in dimension.
91 citations
TL;DR: One of the goals of contemporary science is the atomic or molecular design of materials in order to achieve specific properties as discussed by the authors, and there is special interest in imitating with these designed materials the remarkable integrated functionality we see in biology.
Abstract: One of the goals of contemporary science is the atomic or molecular design of materials in order to achieve specific properties. There is special interest in imitating with these designed materials the remarkable integrated functionality we see in biology. Soft matter offers a particularly good opportunity to realize these goals because of the vast structural space offered by organic systems.
51 citations
42 citations
TL;DR: In this paper, the authors present data on the self-assembly of triblock rodcoil molecules which contain a rigid biphenyl ester segment covalently linked to structurally diverse oligomeric segments.
Abstract: Supramolecular structures have the potential to provide macromolecular behavior using relatively low molar mass building blocks. We present here data on the self-assembly of triblock rodcoil molecules which contain a rigid biphenyl ester segment covalently linked to structurally diverse oligomeric segments. These molecules form supramolecular aggregates with molar masses in the range 105−106 Da, and our experiments probe how supramolecular structure can be manipulated by varying the volume fraction of the coillike flexible segments with respect to that of rod segments. The oligostyrene−oligoisoprene diblock coils were synthesized via anionic polymerization and varied in average length from (6sty, 6iso) to (30sty, 30iso). Small-angle X-ray scattering scans revealed layer spacings corresponding to monolayers that increase in size as the coil's molar mass increases. We observed that an increase in coil volume fraction reduces the thermal stability of the supramolecular structure, but a corresponding increase...
36 citations
TL;DR: The formation of polymer-monomer complexes with the addition of a basic monomer such as L-lysine to negatively charged polymers was found to result in greater adhesive strength relative to homopolymers, suggesting hydrogen bonds and electrostatic forces play a role in the adhesion of the systems to the substrates probed in this work.
Abstract: We report here on poly(amino acid)-based bioadhesives with potential to bond to soft tissues. The systems investigated included homopolymer poly(amino acids), mixtures of poly(amino acids) and amino acids, and blends of different poly(amino acids). Adhesive performance was tested in tension on glass surfaces, chondroitin sulfate surfaces, as well as bovine cartilage surfaces. The amino acid structural units contained acidic, basic, or polar side chains and were found to adhere reasonably well to the surfaces of glass and chondroitin sulfate. The formation of polymer-monomer complexes with the addition of a basic monomer such as L-lysine to negatively charged polymers such as poly(L-aspartic acid) and poly(L-glutamic acid) was found to result in greater adhesive strength relative to homopolymers. Further improvement in adhesion was observed in blends of poly(L-lysine) with polar poly(amino acids) such as poly(L-asparagine). Adhesion on wet cartilage surfaces was the weakest measured but a priming approach ...
22 citations
Patent•
20 Sep 2000
TL;DR: In this article, self-assembling compounds capable of forming birefringent gels when added to an organic medium in an amount of about 0.05 % to about 2 % by weight are disclosed.
Abstract: Self-assembling compounds capable of forming birefringent gels when added to an organic medium in an amount of about 0.05 % to about 2 % by weight are disclosed. A birefringent gel containing a self-assembling compound and an organic monomer can be polymerized to produce an optically birefringent polymer. The birefringent polymer can be melted to provide a birefringent melt that then can be formed into an article of manufacture, like an optical fiber.
10 citations
TL;DR: In this article, two genetic algorithms were developed in order to aid in the design of molecules for self-assembling materials, and the results of the application of this GA to molecules that have been studied experimentally in our laboratory.
8 citations
TL;DR: In this article, a simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers.
Abstract: A simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers. The aggregates are modeled as dipoles in a lattice with an Ising-like penalty associated with reversing the orientation of nearest neighbor dipoles. The choice of the potentials is based on experimental results and structural features of the supramolecular objects. For films of finite thickness, we find a periodic structure along an arbitrary direction perpendicular to the substrate normal, where the repeat unit is composed of two equal width domains with dipole up and dipole down configuration. When a short range interaction between the surface and the dipoles is included the balance between the up and down dipole domains is broken. Our results suggest that due to surface effects, films of finite thickness have a none zero macroscopic polarization, and that the polarization per unit volume appears to be a function of film thickness.
8 citations
TL;DR: In this paper, a simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers.
Abstract: A simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers. The aggregates are modeled as dipoles in a lattice with an Ising-like penalty associated with reversing the orientation of nearest neighbor dipoles. The choice of the potentials is based on experimental results and structural features of the supramolecular objects. For films of finite thickness, we find a periodic structure along an arbitrary direction perpendicular to the substrate normal, where the repeat unit is composed of two equal width domains with dipole up and dipole down configuration. When a short range interaction between the surface and the dipoles is included the balance between the up and down dipole domains is broken. Our results suggest that due to surface effects, films of finite thickness have a none zero macroscopic polarization, and that the polarization per unit volume appears to be a function of film thickness.