Poly(3-octylthiophene)/stearic Acid Langmuir and Langmuir-Blodgett films: Preparation and characterization

Silva, Edilene Assunção da; Oliveira, Vinícius Jessé Rodrigues de; Braunger, Maria Luisa; Constantino, Carlos J. L.; Olivati, Clarissa de Almeida

doi:10.1590/1516-1439.288814

Cited by 13 publications

(13 citation statements)

References 36 publications

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“…While in the presence of THF, the response time is around 5 min and a return to a certain level of stabilization shortly after 13 min of exposure in an inert atmosphere. The response and recovery times of the samples studied are in the same range to the recovery and detection time of organic vapors reported in the literature for polythiophene derivatives detecting volatile organic compounds [38][39][40].…”

Section: Electrical Characterizationsupporting

confidence: 57%

Langmuir-Schaefer films of regioregular polythiophene derivatives as VOCs sensors

Oliveira

Citolino

Camacho

et al. 2018

Materials Chemistry and Physics

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The P3HT and P3OT polymers were scattered on a water-air surface of a Langmuir trough. • Through isotherms (π-A) one can identify the organization phases of the molecules. • The thin films presented linear growth through of Langmuir Schaefer technique. • The thin films on the interdigitated electrode quickly detected the organic vapor. • Raman mapping detected the physical interactions between organic polymers and vapors.

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Section: Electrical Characterizationsupporting

confidence: 57%

Langmuir-Schaefer films of regioregular polythiophene derivatives as VOCs sensors

Oliveira

Citolino

Camacho

et al. 2018

Materials Chemistry and Physics

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“…After identifying, through π-A isotherms and their experimental repetitions, the surface pressure in which the molecules that form the Langmuir films present better organization, this chosen pressure was then kept constant, and it was performed the transfer of these monolayers onto glass substrates with gold interdigitated electrodes (IDE) that were fabricated using photolithography as detailed elsewhere [24]. The deposition was accomplished by two ways: the LB technique where the substrates moved up and down successively in a vertical position in relation to the interface, and the deposition parameters were controlled as seen on Table 1; and using the LS technique in which the substrate horizontally touches the surface containing the Langmuir film and it is lifted afterwards.…”

Section: Experimental Procedures 221 Thin Film Fabricationmentioning

confidence: 99%

The Role of Stitch Yarn on the Delamination Resistance in Non-crimp Fabric: Chemical and Physical Interpretation

Shiino

Pelosi

Cioffi

et al. 2017

J. of Materi Eng and Perform

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Low-bandgap organic polymers, poly[(4,4 bis(2 ethylhexyl)cyclopenta [2,1 b:3,4 b′]dithiophene) 2,6 diyl al (2,1,3 benzothiadiazole) 4,7 diyl](PCPDTBT), and poly [(4,4′ dioctyldithieno[3,2 b:2′,3′d] silol 2,6 diyl) alt (2,1,3 benzothiadiazole) 4,7 diyl)], (Si-PCPDTBT) were analyzed at the air-water interface forming a Langmuir monolayer. In order to form stable monolayers and to transfer to solid supports, amphiphilic molecules of stearic acid (SA) were mixed with them. For the pristine polymers, the floating monolayers were transferred onto solid substrates via the Langmuir-Schaefer (LS) technique. Surface pressure-area isotherms and compressibility modulus curves demonstrated that the SA incorporation to the polymers at the air-water interface modified the rheological properties of the Langmuir films, since the films became less compressible at higher pressures and there is clear conformational reorganization taking place at intermediary pressures. The UV-Vis absorption also depicted the changes on the overall film morphology by the shift on the maximum absorption bands, and along with cyclic voltammetry curves the absorption spectra made it possible to estimate the energy diagrams for the polymers. Photoconductivity effects were observed for all the sample, among which the pristine polymers fabricated by LS showed better results, suggesting that the organization provided by the Langmuir-Blodgett (LB) technique was not enough to overcome the insulating characteristic of the SA molecules in this specific configuration.

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“…As the materials studied here are not amphiphilic molecules, and therefore will not easily self‐assemble on the underlying water substrate, admixtures with SA were prepared at varying percentages. This technique of employing SA, itself an amphiphilic molecule, improves LB film formation and has been effectively demonstrated elsewhere . A Keithley model 238 SMU (Cleveland, Ohio, USA) was used as the voltage source ( V ) and current meter ( I ) to carry out DC electrical measurements on the LB films over IDE devices.…”

Section: Methodsmentioning

confidence: 99%

“…Usually, conducting polymers cannot provide monolayers stable enough to make a Langmuir−Blodgett (LB) film mainly due to the disadvantageous orientation of the polymer chain at the air−water interface, meaning that they do not spread evenly and cannot form true monolayers at the interface . To overcome this issue, the addition of an amphiphilic material, such as a fatty acid, assists the polymer in spreading along the water and leading to a stable hybrid Langmuir monolayer . In this work, the polymers are accordingly evaluated both as prepared and in mixtures with stearic acid (SA) for the formation of LB films.…”

Section: Introductionmentioning

confidence: 99%

Langmuir and Langmuir–Blodgett films of low‐bandgap polymers

Braunger

Silva

Awada

et al. 2018

Polymer International

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Low‐bandgap conjugated polymers have provided a considerable increase in organic photovoltaic efficiencies, however, an understanding of class‐specific nanostructures, necessary to further improve device qualities, remains scarce. Their self‐assembly and associated electronic behaviors in Langmuir−Blodgett (LB) films are used here to provide relationships specific to each polymer, clarifying their structure−property characteristics. The behavior of two low‐bandgap polymers based on cyclopentadithiophene (PCPDTBT) and dithienosilole (Si‐PCPDTBT) units in the Langmuir trough were investigated and it is shown that it is possible to fabricate nanostructured films of low‐bandgap polymers on solid substrates with the LB deposition technique. The polymers were mixed with amphiphilic molecules at well‐defined concentrations to improve the formation of the LB films. The polymers were also deposited by drop‐casting and LB techniques onto interdigitated electrodes to evaluate their electrical properties, and the LB films were characterized for their optical and morphological properties. It was found that both LB and drop‐cast films of PCPDTBT showed higher electrical conductivities than those of Si‐PCPDTBT. Importantly, LB films resulted in higher electrical conductivities – by an order of magnitude − compared to their equivalent mixtures with stearic acid in drop‐cast films, although drop‐cast films without stearic acid gave higher conductivities. This fine‐tuning of the molecular architectures of the films is thus demonstrated to directly affect the physical properties and may lead to an improvement in device efficiencies in future applications. © 2018 Society of Chemical Industry

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Poly(3-octylthiophene)/stearic Acid Langmuir and Langmuir-Blodgett films: Preparation and characterization

Cited by 13 publications

References 36 publications

Langmuir-Schaefer films of regioregular polythiophene derivatives as VOCs sensors

Langmuir-Schaefer films of regioregular polythiophene derivatives as VOCs sensors

The Role of Stitch Yarn on the Delamination Resistance in Non-crimp Fabric: Chemical and Physical Interpretation

Langmuir and Langmuir–Blodgett films of low‐bandgap polymers

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