scholarly journals Experimental review of PEI electrodeposition onto copper substrates for insulation of complex geometries

RSC Advances ◽  
2021 ◽  
Vol 11 (55) ◽  
pp. 34599-34604
Author(s):  
J.-C. Zirignon ◽  
A. J. Capezza ◽  
X. Xiao ◽  
R. L. Andersson ◽  
M. Forslund ◽  
...  

Electrophoretic deposition relying on electrodeposition of charged polymers via modulated electrical fields is reported. Superior surface finishes that could pass a dielectric withstand test at 10 kV mm−1 were obtained for pulsed potentials at 20 V.

1965 ◽  
Vol 15 (1) ◽  
pp. 40-48
Author(s):  
D. R. Brown ◽  
F. W. Salt

2019 ◽  
Author(s):  
Zacharias Kinney ◽  
Viraj Kirinda ◽  
Scott Hartley

<p>Higher-order structure in abiotic foldamer systems represents an important but largely unrealized goal. As one approach to this challenge, covalent assembly can be used to assemble macrocycles with foldamer subunits in well-defined spatial relationships. Such systems have previously been shown to exhibit self-sorting, new folding motifs, and dynamic stereoisomerism, yet there remain important questions about the interplay between folding and macrocyclization and the effect of structural confinement on folding behavior. Here, we explore the dynamic covalent assembly of extended <i>ortho</i>-phenylenes (hexamer and decamer) with rod-shaped linkers. Characteristic <sup>1</sup>H chemical shift differences between cyclic and acyclic systems can be compared with computational conformer libraries to determine the folding states of the macrocycles. We show that the bite angle provides a measure of the fit of an <i>o</i>-phenylene conformer within a shape-persistent macrocycle, affecting both assembly and ultimate folding behavior. For the <i>o</i>-phenylene hexamer, the bite angle and conformer stability work synergistically to direct assembly toward triangular [3+3] macrocycles of well-folded oligomers. For the decamer, the energetic accessibility of conformers with small bite angles allows [2+2] macrocycles to be formed as the predominant species. In these systems, the <i>o</i>-phenylenes are forced into unusual folding states, preferentially adopting a backbone geometry with distinct helical blocks of opposite handedness. The results show that simple geometric restrictions can be used to direct foldamers toward increasingly complex geometries.</p>


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