Enabling nanotechnology with self assembled block copolymer patterns

Directing the self-assembly of block copolymers

This Review describes the application of nitroxides to synthesis and polymer chemistry. The synthesis and physical properties of nitroxides are discussed first. The largest section focuses on their application as stoichiometric and catalytic oxidants in organic synthesis. The oxidation of alcohols and carbanions, as well as oxidative C-C bond-forming reactions are presented along with other typical oxidative transformations. A section is also dedicated to the extensive use of nitroxides as trapping reagents for C-centered radicals in radical chemistry. Alkoxyamines derived from nitroxides are shown to be highly useful precursors of C-centered radicals in synthesis and also in polymer chemistry. The last section discusses the basics of nitroxide-mediated radical polymerization (NMP) and also highlights new developments in the synthesis of complex polymer architectures.

Nitroxides: applications in synthesis and in polymer chemistry.

Functional nanomaterials based on block copolymer self-assembly

Block copolymers constitute a fascinating set of self-assembled materials ex- hibiting compositional heterogeneities on the nanometer length scale. While traditionally employed as thermoplastic elastomers, asphalt modifiers, and adhesives, the potential of self-assembled block copolymers for nanotechnological applications has been realized in the past decade and many examples have now appeared in the literature. As indicated by the title, this review covers a specific aspect of block copolymers as tools for prepar- ing nanoscopic materials. Nanoporous materials can be generated by selective removal of one component from a self-assembled block copolymer. These materials exhibit the pore size and pore topology of their parent structures and can be used as nanolithographic masks, separation membranes and nanomaterial templates. The work described within covers the published work in the field since the first report of nanoporous materials from ordered block copolymers nearly two decades ago. After an introductory section and historical account, sections on nanolithography, membranes, monoliths, and templates follow. The review ends with a summary and outlook on this exciting research arena in block copolymer science and technology.

Nanoporous materials from block copolymer precursors

Protection and polymerization of functional monomers: anionic living polymerization of protected monomers

Preparation de copolymeres sequences par polymerisation anionique vivante de (vinyl-4 phenyl) dimethyl propoxy-2 silane (I) et d'isoprene, par reticulation de poly (I) et decomposition des sequences isoprene par l'ozone

Polymerization of monomers containing functional silyl groups. 7. Porous membranes with controlled microstructures

Polymerisation des derives trimethoxysilyl et triisopropoxysilyl. Copolymerisation sequencee avec l'isoprene

Polymerization of monomers containing functional silyl groups. 6. Anionic polymerization of 2-(trialkoxysilyl)-1,3-butadiene

Polymerisation anionique du vinyl-4 benzoate de t-butyle amorcee par des oligo(α-methylstyryl) disodium, -dipotassium et -dicesium; a −95 o C avec les sels de potassium, obtention de polymere a MND etroite et le MW controlable, demontrant la formation d'un polymere vivant stable. Preparation par cette voie de copolymeres trisequences avec le MMA, le styrene et l'isoprene. Hydrolyse quantitative du poly(vinyl-4 benzoate de t-butyle) par Me 3 SiCl/NaI

Protection and polymerization of functional monomers. 13. Anionic living polymerization of tert-butyl 4-vinylbenzoate

Anionic polymerization of 4-[N,N-bis(trimethylsilyl)aminomethyl]styrene (1) and 4-{2-[N,N-bis(trimethylsilyl)amino]ethyl}styrene (2) were carried out at −78°C in tetrahydrofuran (THF)/pentane mixtures with butyllithium, oligo(α-methylstyryl)lithium, oligo(α-methylstyryl)potassium, and cumylpotassium. Polymerizations of 1 and 2 proceed without chain transfer and termination reactions to give stable “living polymers” when butyllithium or oligo(α-methylstyryl)lithium are used as initiator. The resulting polymers have predictable molecular weights and narrow molecular weight distributions (ratio of weight- to number-average molecular weights, Mw/Mn = 1,04–1,14). Under mild acidic conditions (pH 3–5 in THF/water), cleavage of the NSi bonds in the polymers is completely achieved to give well-defined poly(4-aminomethyl)styrene and poly[4-(2-aminoethyl)styrene]. The triblock copolymers of polystyrene-block-poly(1)-block-polystyrene and polystyrene-block-poly(2)-block-polystyrene are readily prepared in quantitative yields by sequential polymerization of styrene with living poly(1) or living poly(2).

Protection and polymerization of functional monomers, 14. Anionic living polymerization of 4‐[N,N‐bis(trimethylsilyl)‐aminomethyl]styrene and 4‐{2‐[N,N‐bis(trimethylsilyl)amino]ethyl}styrene

Seiichi Nakahama

Papers

Protection and polymerization of functional monomers: anionic living polymerization of protected monomers

Polymerization of monomers containing functional silyl groups. 7. Porous membranes with controlled microstructures

Polymerization of monomers containing functional silyl groups. 6. Anionic polymerization of 2-(trialkoxysilyl)-1,3-butadiene

Protection and polymerization of functional monomers. 13. Anionic living polymerization of tert-butyl 4-vinylbenzoate

Protection and polymerization of functional monomers, 14. Anionic living polymerization of 4‐[N,N‐bis(trimethylsilyl)‐aminomethyl]styrene and 4‐{2‐[N,N‐bis(trimethylsilyl)amino]ethyl}styrene