scholarly journals Reversible gel–sol photoswitching with an overcrowded alkene-based bis-urea supergelator

2016 ◽  
Vol 7 (7) ◽  
pp. 4341-4346 ◽  
Author(s):  
Sander J. Wezenberg ◽  
Christelle M. Croisetu ◽  
Marc C. A. Stuart ◽  
Ben L. Feringa
Keyword(s):  
Phase Transition ◽  
Molecular Weight ◽  
Uv Irradiation ◽  
Low Molecular Weight ◽  
Reversible Gel

A low-molecular-weight organogel composed of photoresponsive bis-urea gelators can undergo a reversible gel–sol phase transition upon UV irradiation.

Tertiary amine catalyzed photo-induced controlled radical polymerization of methacrylates

2015 ◽  
Vol 6 (30) ◽  
pp. 5362-5368 ◽  
Author(s):  
Qiang Fu ◽  
Thomas G. McKenzie ◽  
Shereen Tan ◽  
Eunhyung Nam ◽  
Greg G. Qiao
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Uv Irradiation ◽  
Tertiary Amine ◽  
Controlled Radical Polymerization ◽  
Low Molecular Weight ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
End Group

A novel tertiary amine catalyst and trithiocarbonate synergistic photo-induced controlled radical polymerization of methacrylates has been realized under mild UV irradiation, yielding polymethacrylates with low molecular weight distributions and excellent end-group fidelity.

Electrorheological Effect in the Nematic and the Smectic A Phases of Low Molecular Weight Liquid Crystal

1999 ◽  
Vol 13 (14n16) ◽  
pp. 2005-2010 ◽  
Author(s):  
Keishi Negita
Keyword(s):  
Phase Transition ◽  
Molecular Weight ◽  
Liquid Crystal ◽  
Electric Field ◽  
Low Molecular Weight ◽  
Large Decrease ◽  
Smectic A ◽  
General Properties ◽  
Electrorheological Effect ◽  
Phase Sequence

Electrorheological (ER) effects in the nematic (Ne), the smectic A (SmA) and the isotropic (Is) phases of octyloxy cyanobiphenyl (8OCB) are studied. When an electric field is applied, a large decrease of the viscosity is observed in the Sm A phase, while in the Ne phase an increase of the viscosity is recognized with an anomalous ER effect near the SmA-Ne phase transition. These behaviors are suggested to be general properties of the liquid crystal exhibiting the phase sequence of SmA-Ne-Is.

Impact of “half-crown/two carbonyl”–Ca2+ metal ion interactions of a low molecular weight gelator (LMWG) on its fiber to nanosphere morphology transformation with a gel-to-sol phase transition

Soft Matter ◽  
2018 ◽  
Vol 14 (28) ◽  
pp. 5821-5831 ◽  
Author(s):  
Arunava Maity ◽  
Ananta Dey ◽  
Mrinal Kanti Si ◽  
Bishwajit Ganguly ◽  
Amitava Das
Keyword(s):  
Phase Transition ◽  
Molecular Weight ◽  
Metal Ion ◽  
Low Molecular Weight ◽  
Coordination Site ◽  
Ion Interactions ◽  
Metal Ion Interactions ◽  
Low Molecular Weight Gelator

We report here a smart functional low molecular weight gelator (LMWG) L, containing an unusual metal ion coordination site, i.e. “half-crown/two carbonyl”.

Synthesis and Photoresist Property of a Polyamide Containing a Naphthylurea Moiety

1998 ◽  
Vol 10 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Satoshi Akimoto ◽  
Mitsutoshi Jikei ◽  
Masa-Aki Kakimoto
Keyword(s):  
Molecular Weight ◽  
Uv Irradiation ◽  
Uv Light ◽  
Crosslinking Agent ◽  
Low Molecular Weight ◽  
Aprotic Solvents ◽  
Negative Tone ◽  
Model Reactions

A novel polyamide containing a naphthylurea moiety as the photoreaction site (Np Urea-PA) was synthesized by polycondensation of N-3, 5-dicarboxyphenyl- N′-1-naphthylurea and 4, 4′-oxydianiline (ODA). The model reactions, which consisted of irradiation by UV light of the low molecular weight aromatic ureas and isocyanate, suggested that the photochemistry involves an aromatic isocyanate intermediate. Np Urea-PA acts as the negativeworking resist, by UV irradiation through a quartz mask followed by development using aprotic solvents such as N, N-dimethylacetamide (DMAc). The contrast of the negative tone image was improved by using 20 wt% of p-xylylenediamine ( pXDA) as a crosslinking agent.

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