Fei, Huafeng; Yavitt, Benjamin M.; Kopanati, Gayathri; Watkins, James J.
Effect of side chain and backbone length on lamellar spacing in polystyrene-block-poly(dimethyl siloxane) brush block copolymers
We report the synthesis of polystyrene-block-poly(dimethyl siloxane) (PS-b-PDMS) brush block copolymers (BBCPs) through sequential ROMP of norbornene-modified macromonomers (-NB) and explore the effect of side chain length (Nsc) and total backbone degree of polymerization (Nbb) on the self-assembly of lamellar morphologies. Group I (PS-NB Mn = 2.9 kg/mol, PDMS-NB Mn…
Morphological Evolution of Poly(solketal methacrylate)-block-polystyrene Copolymers in Thin Films
Yu, Duk Man; Smith, Darren M.; Kim, Hyeyoung; Mapas, Jose Kenneth D.; Rzayev, Javid; Russell, Thomas P.
The morphological evolution of the lamellar microdomains in the thin films of symmetric poly(solketal methacrylate-b-styrene) (PSM-b-PS) copolymers that can be converted into poly(glycerol monomethacrylate-b-styrene) (PGM-b-PS) copolymers through acid hydrolysis reaction was investigated. This simple chemical transformation was performed in the solid state using trifluoroacetic acid vapor,
Shape modulation of squaramide-based supramolecular polymer nanoparticles
Talens, Victorio Saez; Makurat, D. M. M.; Liu, Tingxian; Dai, Wei; Guibert, Clément; Noteborn, Willem E. M.; Voets, Ilja K.; Kieltyka, Roxanne E.
We report the synthesis and self-assembly of a library of squaramide-based bolaamphiphiles with variable hydrophobic and hydrophilic domain sizes, consisting of varied aliphatic chains (n = 2 to 12 methylene repeat units) and linear oligo(ethylene glycol) (m = 11 to 36 repeat units), to understand their effect on the formation…
Aggregation behavior of the amyloid model peptide NACore
Pallbo, Jon; Sparr, Emma; Olsson, Ulf
The aggregation of the 11 residue long NACore peptide segment of ?-synuclein (68-GAVVTGVTAVA-78) has been investigated using a combination of cryogenic transmission electron microscopy (cryo-TEM), small- and wide-angle X-ray scattering, and spectroscopy techniques. The aqueous peptide solubility is pH dependent, and aggregation was triggered by a pH quench from pH…
Self-assembly of oppositely charged polyelectrolyte block copolymers containing short thermoresponsive blocks
Hees, I. A. van; Swinkels, P. J. M.; Fokkink, R. G.; Velders, A. H.; Voets, I. K.; Gucht, J. van der; Kamperman, M.
The assembly of oppositely charged block copolymers, containing small thermoresponsive moieties, was investigated as a function of salt concentration and temperature. Aqueous solutions of poly--b-poly (NIPAM44-b-DMAEMA216) and PNIPAM-b-poly-b-PNIPAM (NIPAM35-b-AA200-b-NIPAM35) were mixed in equal charge stoichiometry, and
Widely tunable persistent micelle templates via homopolymer swelling
Sarkar, Amrita; Thyagarajan, Akshay; Cole, August; Stefik, Morgan
The combination of precision control with wide tunability remains a challenge for the fabrication of porous nanomaterials suitable for studies of nanostructurebehavior relationships. Polymer micelle templates broadly enable porous materials, however micelle equilibration hampers independent pore and wall size control. Persistent micelle templates (PMT) have emerged as a kinetic controlled
Twisted Ribbon Aggregates in a Model Peptide System
Rüter, Axel; Kuczera, Stefan; Pochan, Darrin J.; Olsson, Ulf
The model peptides A8K and A10K self-assemble in water into ca. 100 nm long ribbon-like aggregates. These structures can be described as ?-sheets laminated into a ribbon structure with a constant elliptical cross-section of 4 by 8 nm, where the longer axis corresponds to a finite number, N ? 15,…
Self-Assembly of the Bio-Surfactant Aescin in Solution: A Small-Angle X-ray Scattering and Fluorescence Study
Dargel, Carina; Geisler, Ramsia; Hannappel, Yvonne; Kemker, Isabell; Sewald, Norbert; Hellweg, Thomas
This work investigates the temperature-dependent micelle formation as well as the micellar structure of the saponin aescin. The critical micelle concentration ( cmc ) of aescin is determined from the concentration-dependent autofluorescence (AF) of aescin. Values between cmcaescin,AF (10°C) = 0.38 ± 0.09 mM and cmcaescin,AF (50°C) = 0.32 ±…
Preparation of isoporous membranes from low χ block copolymers via co-assembly with H-bond interacting homopolymers
Zhu, Guo-Dong; Yang, Cao-Ying; Yin, Yu-Rong; Yi, Zhuan; Chen, Xian-Hong; Liu, Li-Fen; Gao, Cong-Jie
Self-assembly and non-solvent induced phase separation (SNIPS) was extensively used in the fabrication of isoporous membranes for its compatibility with massive production. However, for the well-defined SNIPS, preparation of isoporous membranes from low χ block copolymers is challenging because self-assembly of these polymers is usually hard to induce. In this…
Core-crystalline nanoribbons of controlled length via diffusion-limited colloid aggregation
Schmarsow, Ruth N.; Ceolín, Marcelo; Zucchi, Ileana A.; Schroeder, Walter F.
It has been previously reported that poly(ethylene) (PE)-based block copolymers self-assemble in certain thermosetting matrices to form a dispersion of one-dimensional (1D) nanoribbons. Such materials exhibit exceptional properties that originate from the high aspect ratio of the elongated nano-objects. However, the ability to prepare 1D assemblies with well-controlled dimensions is…