Hydrogen-Bonding Fabrication of NLO Langmuir−Blodgett Films with Nontraditional Molecular Architecture and Unique Thermal Stability

Abstract

The SHG active nontraditional LB architectures of monolayers and multilayers were fabricated based on molecular interactions of hydrogen bonding. After photopolymerization of the diacetylene groups, the SHG thermal stability of the obtained LB films could be improved substantially and all the polymerized films exhibited unique SHG thermal rebounding phenomena.

Pure and mixed films of a nitrostilbene derivative at the air–water interface, Langmuir–Blodgett multilayer fabrication, and optical characterization

“…We should bear in mind that the fabrication of nitrostilbene LB films is difficult, leading to ill-defined multilayers due to the large tendency for aggregation into 3D structures because of the strong cohesive forces among molecules, as reported before [29]. The molecule we present here has the particularity of containing two alkyl chains, versus other previously studied nitrostilbenes without hydrophobic chains [29,30] or with only one chain [14][15][16]22]. Molecules having two alkyl chains have been reported to produce more stable and higher quality LB films than those having only one alkyl chain [31][32][33].…”

Synthesis and Nonlinear Studies on Selected Organic Compounds in Nanostructured Thin Films

“…The driving forces of coherent monolayer formation are the hydrophobic interactions between the nonpolar parts and the interaction between the polar groups and the water subphase. Wang et al [71] propose an unconventional method to prepare NLO LB films based on the molecular electrostatic interaction of hydrogen bonding in a chromophore modified with urea.…”

“…Figure 12. П-A isotherm of Langmuir film of NAEDTDU (adapted with the permission from reference [71]).…”

Orderly arranged NLO materials on exfoliated layered templates based on dendrons with alternating moieties at the periphery

“…Therefore, various strategies have been devised to achieve polar order without resorting to electric poling, which include Langmuir-Blodgett (LB) growth, molecular self-assembly, etc. [19][20][21][22] However, the problem of limited long-term NLO stability at elevated temperatures is still present in these systems. Recently, the assembly behaviors of organic molecules on the layered silicates such as montmorillonite (MMT) were investigated.…”