Many poly(ferrocenyldimethylsilane) (PFS) block copolymers form fiber-like micelles with a semicrystalline core in selective solvents. Solvent effects on micelle formation are not well understood. This paper compares micelle formation for a sample of PFS50–PI1000 (the subscripts refer to the number-average degrees of polymerization) in decane with that in tert-butyl acetate (tBA), a more polar solvent. When micelle formation is seeded, by adding block copolymer as a concentrated solution in tetrahydrofuran to solutions of micelle fragments, micelle growth was similar in both solvents. Micelles with a narrow length distribution were formed and the length increased in proportion to the amount of polymer added. In contrast, when micelles were prepared by heating a sample of the block copolymer in decane or tBA to 90 °C and allowing the solution to cool, pronounced differences were observed. In decane, micelles with a uniform width (10 nm) and a length on the order of 5 μm formed after 1 h, and grew to about 10 μm after 5 days. In tBA, aliquots taken from solution 1 h after cooling appeared to undergo microphase separation only upon solvent evaporation. Ribbon-like structures were observed after 1 and 5 days aging, but these evolved into fiber-like structures with a uniform 10 nm width and lengths greater than 30 μm after 25 days. These differences observed in the rate of micelle formation likely reflect differences in the nucleation stage of micelle formation. tBA is a better solvent for the PFS block than decane. As a consequence, it appears to take much longer for semicrystalline micelle nuclei to form in tBA. The seeded growth experiments demonstrate that once seed micelles are present, growth occurs similarly in both solvents.

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Homogeneous penetration of atmospheric pressure uniform air plasma (APUAP) into thin gaps is highly warranted for multipurpose processing of materials. Here, we report APUAP generation in a 7 mm discharge gap with ambient air as the working gas, well beyond the presently maximum achievable 4 mm. Driven by a short pulse high voltage power, a 7 mm wide and 60 mm long uniform air plasma sheet is generated. The discharge is robust and the uniformity is not affected by the complex and variable components of ambient air, as is the case for most plasma discharges in air. Ultrafast photography shows that, different from previous reports, the discharge initiates in the whole air gap simultaneously and brightens quickly with the fast rise of the pulsed voltage. The generation of uniform plasma is mainly attributed to the high density of seed electrons and the reduced number density of molecules in air. Moreover, the achievable gas temperature of up to 1300 K indicates that this type of plasma is suitable for processing of a broad range of materials.

The established model and the proposed compensation method can be used for the cable-driven continuum robot to guarantee safety and stability in MIS.