Long‐Range Ordered Double Gyroid Structures via Solution Casting from Poly(2,2,2‐trifluoroethyl methacrylate)‐ block ‐poly(2‐vinyl pyridine)

2021 ◽  
Vol 222 (22) ◽  
pp. 2170044
Author(s):  
Sho Kurimoto ◽  
Liang Tong ◽  
Hayato Maeda ◽  
Yuta Nabae ◽  
Teruaki Hayakawa
Keyword(s):  
Long Range ◽  
Solution Casting ◽  
Vinyl Pyridine ◽  
Double Gyroid

scholarly journals Mesoscale networks and corresponding transitions from self-assembly of block copolymers

2021 ◽  
Vol 118 (11) ◽  
pp. e2022275118
Author(s):  
Cheng-Yen Chang ◽  
Gkreti-Maria Manesi ◽  
Chih-Ying Yang ◽  
Yu-Chueh Hung ◽  
Kai-Chieh Yang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Evaporation Rate ◽  
Diblock Copolymers ◽  
Solution Casting ◽  
Selective Solvent ◽  
Space Group ◽  
Self Assembling ◽  
Planar Network ◽  
Double Gyroid ◽  
Double Diamond

A series of cubic network phases was obtained from the self-assembly of a single-composition lamellae (L)-forming block copolymer (BCP) polystyrene-block-polydimethylsiloxane (PS-b-PDMS) through solution casting using a PS-selective solvent. An unusual network phase in diblock copolymers, double-primitive phase (DP) with space group of Im3¯m, can be observed. With the reduction of solvent evaporation rate for solution casting, a double-diamond phase (DD) with space group of Pn3¯m can be formed. By taking advantage of thermal annealing, order–order transitions from the DP and DD phases to a double-gyroid phase (DG) with space group of Ia3¯d can be identified. The order–order transitions from DP (hexapod network) to DD (tetrapod network), and finally to DG (trigonal planar network) are attributed to the reduction of the degree of packing frustration within the junction (node), different from the predicted Bonnet transformation from DD to DG, and finally to DP based on enthalpic consideration only. This discovery suggests a new methodology to acquire various network phases from a simple diblock system by kinetically controlling self-assembling process.

Long range target recognition and identification of camouflaged armored vehicles.

1979 ◽  
Author(s):  
William L. Warnick ◽  
Garvin D. Chastain ◽  
William H. Ton
Keyword(s):  
Long Range ◽  
Target Recognition ◽  
Armored Vehicles
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