A novel silicon‐containing molecular resist material based on polyhedral oligomeric silsesquioxane, possessing trimethoxysilyl groups, was designed in order to reduce post‐exposure delay problems and to improve resolution. Since the acid‐catalyzed cross‐linking reaction of trimethoxysilyl groups occurs at room temperature, there is no necessity of post‐exposure bake. The molecular resist showed 0.7 µm line‐and‐space patterns using a mercury–xenon lamp in a contact printing mode and 100 nm line‐and‐space patterns using electron beam lithography.
A series of new copolymers with high molecular weight and low polydispersity, prepared from tetrahydroxydinaphthyl, tetrahydroxyspirobisindane, and tetrafluoroterephthalonitrile monomers, prevent efficient space packing of the stiff polymer chains and consequently show intrinsic microporosity. One copolymer, DNPIM‐33, has an excellent combination of properties with good film‐forming characteristics and gas transport performance, and exhibits higher selectivity than the corresponding spirobisindane‐based homopolymer PIM‐1 for gas pairs, such as O2/N2, with a corresponding small decrease in permeability. This work demonstrates that significant improvements in properties may be obtained through development of copolymers with intrinsic microporosity (CoPIMs) that extends the spectrum of high‐molecular‐weight ladder structures of poly(dibenzodioxane)s.
A new synthetic approach to furo[2′,3′:3,4]cyclohepta[1,2‐b]indolium chlorides is elaborated starting from 2‐acetylaminoaryldifurylmethanes or 2‐aminoaryldifurylmethanes under treatment with methanolic HCl solution. The reaction proceeds in three steps: recyclization, intramolecular cyclization, and disproportionation. In this case the furan ring takes part in building up both pyrrole and seven‐membered rings. The same salts can be obtained directly from 2‐acetylaminobenzaldehydes and 2‐methylfuran under similar conditions without isolation of corresponding 2‐acetylaminoaryldifurylmethanes. 相似文献
We show that small quantities of 1,3:2,4‐di(4‐chlorobenzylidene) sorbitol dispersed in poly(ε‐caprolactone) provide a very effective self‐assembling nanoscale framework which, with a flow field, yields extremely high levels of polymer crystal orientation. During modest shear flow of the polymer melt, the additive forms highly extended nano‐particles which adopt a preferred alignment with respect to the flow field. On cooling, polymer crystallisation is directed by these particles. This chloro substituted dibenzylidene sorbitol is considerably more effective at directing the crystal growth of poly(ε‐caprolactone) than the unsubstituted compound.
