Patterning of Hierarchically Aligned Single-Walled Carbon Nanotube Langmuir−Blodgett Films by Microcontact Printing

Abstract

We present a patterning method for hierarchically aligned assembly of single-walled carbon nanotubes (SWNTs) using a combination of the Langmuir-Blodgett (LB) technique and soft lithography. The LB technique allows one to control the alignment and the surface density of SWNTs by adjusting surface pressure of the film at the air-water interface. The aligned SWNT Langmuir films are successfully transferred onto the polydimethylsiloxane (PDMS) or silicon substrate with unidirectional alignment, and SWNT patterns with various shapes are fabricated on silicon and flexible poly(ethylene terephthalate) (PET) substrates by contacting and peeling off the PDMS stamp from the substrates via microcontact printing or lift-up methods. The SWNT patterning technique using the combination of soft lithography and the LB method can be applied in various fields, such as flexible high-speed transistors, high-efficiency solar cells, and transparent electrodes.

Nano-Bioelectronics

“…Two major strategies for producing CNT arrays include post-synthesis assembly 254–255 and the aligned growth. 206,256–258 Post synthesis assembly approaches, which are similar to the assembly methods for SiNWs, include flow directed alignment, 259–265 Langmuir–Blodgett assembly, 266–267 electric field 268–270 and magnetic field 271–274 directed alignment, mechanical shearing, 275–280 or blown bubble film techniques. 136,281 On the other hand, in situ growth approach produces aligned CNTs during growth using controlled CVD processes, including gas flow directed growth, 282–290 external field directed growth, 232,291–292 , and surface-directed growth.…”

Dynamic Raman Spectroelectrochemistry of Single Walled Carbon Nanotubes modified electrodes using a Langmuir-Schaefer method

“…However, for some chemical systems it is possible to obtain informative spectra in shorter integration times, allowing us to work in a real dynamic regime. [24][25][26][27][28][29][30][31][32][33]. Moreover, these bottom-up techniques are very useful to control the properties (thickness, porosity, etc) of the films more than any other one.…”

Directed Assembly of Hybrid Nanomaterials and Nanocomposites

“…Interfacial shear forces generated by Langmuir–Blodgett (LB) and Langmuir–Schaefer (LS) techniques have also been widely utilized to assemble high‐density films of anisotropic nanoparticles . Typically, nanoparticle suspensions are spread on a liquid (usually water) surface followed by application of an appropriate level of compression to form a Langmuir monolayer.…”

“…Given their high responsivity to temperature, mechanical stress, and electromagnetic and optical fields, LC mesophases provide attractive options for engineering metamaterials, as demonstrated by recent reports. [101d,155] The work of Smalyukh et al discussed earlier is relevant in this context. [33e] Recently reported work by Rogach and co‐workers demonstrates the feasibility of the LC‐directed concept for photonics applications by using photoalignment of azo‐based LC phases to control and pattern the orientation of semiconducting nanorods .…”