Photodesign and fabrication of surface relief gratings on films of polyimide-based supramolecular systems obtained using host-guest strategy

Sava, Ion; Stoica, Iuliana; Topală, Ionuț; Mihăilă, Ilarion; Barzic, Andreea Irina

doi:10.1016/j.polymer.2022.124829

Cited by 7 publications

(9 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, considering the frequency of 10 Hz as a representative example, the maximum σ-relaxation peak is observed at 235 • C for SP42, 201 • C for SP43, and 178 • C for SP44 films. A similar tendency in the results was observed by measuring T g by DSC, as was reported early [30]. Figure 5 presents the evolution of the measured conductivity as a function of frequency at room temperature (a) and at 150 • C (b), respectively.…”

Section: Dielectric Propertiessupporting

confidence: 85%

Testing the Performance of the Azo-Polyimide Supramolecular Systems as Substrate for Sensors Based on Platinum Electrodes

Sava¹,

Asăndulesa²,

Barzic³

et al. 2023

Materials

Self Cite

View full text Add to dashboard Cite

Azo-polyimide films with supramolecular structure were obtained by casting onto glass plates a mixture based on polyamidic acid and different quantities of azochromophore, followed by thermal treatment to realize the final azo-polyimide structure. The dielectric characteristics of the supramolecular structure of polymer films were investigated by broad-band dielectric spectroscopy measurements at different temperatures and frequencies. The free-standing films proved to be flexible and tough and maintained their integrity after repeated bending. The work of adhesion at the polymer/platinum interface was calculated after the evaluation of the surface energy parameters before and after plasma treatment. Atomic force microscopy was used to image the surface morphology, the evolution of the roughness parameters, and the adhesion force between the platinum-covered tip and the polymer surface, registered at the nanoscale with the quantity of the azo dye introduced in the system. The simulation of the columnar growth of a platinum layer was made to provide information about the deposition parameters that should be used for optimal results in the deposition of platinum electrodes for sensors.

show abstract

Section: Dielectric Propertiessupporting

confidence: 85%

Testing the Performance of the Azo-Polyimide Supramolecular Systems as Substrate for Sensors Based on Platinum Electrodes

Sava¹,

Asăndulesa²,

Barzic³

et al. 2023

Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…This was an indicator that the proper working wavelength for the patterning experiments will be the third harmonic of a pulsed Nd:YAG laser (355 nm). In addition, from our previous experience [ 15 , 36 , 37 , 38 ], we could choose the most suitable irradiation conditions to study the influence of the azo-chromophore type on the resulting micro/nano structures (presented in the Experimental part).…”

Section: Resultsmentioning

confidence: 99%

“…Thus, the slightly more intense absorption bands in the IR spectrum of the supramolecular azo-polyimide films in the range of 3680–3250 cm −1 can be observed, which is characteristic of H-bonds. This domain includes absorption bands of the valence vibrations of free or bounded aromatic hydroxyl groups, hydrogen bonds between the carbonyl in imide rings, and OH group from chromophore [ 15 ]. The broad absorption band with a maximum of around 3500 cm −1 was assigned to the intermolecular H-bonded OH group of the supramolecular azo-polyimide films ( Figure A7 ).…”

Section: Figure A1mentioning

confidence: 99%

“…Some reports state that in high glass transition polymers, the SRGs are the outcome of optically induced mass transport with insignificant thermal effects [ 12 ], whereas others take into account thermal ablation and photodegradation processes [ 13 ]. Production of bulk birefringence and engraving of SRGs in azo-polymer systems afford their use in holographic devices [ 14 ], liquid crystal displays [ 15 ], optical switching [ 16 ], light couplers for waveguides [ 17 ], optical storage [ 18 ], and shape memory devices [ 19 ]. Based on the above described molecular phenomena, the researchers were focused on the development of SRGs on several kinds of polymer structures containing azo-chromophores, such as modified chitosan [ 20 ], polymer salt [ 21 ], polymethyl methacrylate [ 22 ], polystyrene [ 23 ], poly(vinyl alcohol) with azobenzene side chains [ 24 ], and polyimides (PIs) [ 25 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Impact of the Azo-Chromophore Sort on the Features of the Supramolecular Azopolyimide Films Desired to Be Used as Substrates for Flexible Electronics

Stoica¹,

Epure

Barzic³

et al. 2022

IJMS

Self Cite

View full text Add to dashboard Cite

High-performance supramolecular polyimide systems were synthesized via a simple and innovative approach using two types of azo-chromophores, leading to concomitant special properties: high thermostability, the ability to be processed in the form of films with high flexibility, adequate morphological features, and good structuring capacity via phase mask ultraviolet (UV) laser irradiation, induced by the presence of the azo groups (–N=N–). The dimension and the anisotropy degree of the micro/nano patterns obtained on the surface of the flexible films (determined by atomic force microscopy) depend on the azo-dye type used in the supramolecular azopolyimide synthesis, which were higher when the azo-chromophore containing a –cyano group (−C≡N) was used. The molecular dynamics method, an excellent tool for an in-depth examination of the intermolecular interactions, was used to explain the morphological aspects. Energetic, dynamic and structural parameters were calculated for the two systems containing azo-chromophores, as well as for the pristine polymer system. It was highlighted that the van der Waals forces make a major contribution to the intermolecular interactions. The results from the combination of the dynamic analysis and the concentration profile explain the better mobility of the polyimide chains with a maximum content of azo groups in the cis configuration compared to the other systems. Taking all these data into account, the surfaces of the films can be tuned as required for the proposed applications, namely as substrates for flexible electronis.

show abstract

“…One category of polymers that best meets the described technical demands is represented by polyimides (PIs), which are acknowledged for their capacity to remain stable under heat, moisture, chemical substances, and radiation. The balance between the PI’s thermal, optical, morphological, and wettability characteristics can be adjusted by means of the chemical structure [ 11 , 12 ]. The literature shows that there are not many studies dealing with PI involvement in solar cell applications and they principally describe fully aromatic commercial structures (Kapton [ 13 ] or Upilex [ 14 ]), while others analyze certain aromatic non-commercial PIs [ 15 , 16 ], all being employed as flexible substrates.…”

Section: Introductionmentioning

confidence: 99%

Polyimide Layers with High Refractivity and Surface Wettability Adapted for Lowering Optical Losses in Solar Cells

Barzic¹,

Albu²,

Hulubei³

et al. 2022

Polymers

Self Cite

View full text Add to dashboard Cite

The performance of photovoltaics with superstrate configuration is limited by the rigidity and low refractivity of a classical glass cover. In this work, two polyimides (PIs) and two copolyimides combined in the main chain cycloaliphatic moieties, aromatic sequences, chalcogen atoms, and having/lacking fluorine atoms, are proposed as shielding covers for solar cells. The samples containing small cycloaliphatic moieties displayed high transmittance above 80% at 550 nm. The refractive index values under changeable wavelengths and temperatures were shown to influence the magnitude of the reflection losses. At the sample interface with the transparent electrode, optical losses were reduced (~0.26%) in comparison to the classical glass (~0.97%). The samples with the best optical features were further subjected to a surface treatment to render the self-cleaning ability. For this, a new approach was used residing in irradiation with the diffuse coplanar surface barrier discharge (DCSBD), followed by spraying with a commercial substance. Scanning electron microscopy and atomic force microscopy scans show that the surface characteristics were changed after surface treatment, as indicated by the variations in root mean square roughness, surface area ratio, and surface bearing index values. The proposed PI covers diminish the optical losses caused by total internal reflection and soiling, owing to their adapted refractivity and superhydrophobic surfaces (contact angles > 150°), and open up new perspectives for modern photovoltaic technologies.

show abstract

Photodesign and fabrication of surface relief gratings on films of polyimide-based supramolecular systems obtained using host-guest strategy

Cited by 7 publications

References 65 publications

Testing the Performance of the Azo-Polyimide Supramolecular Systems as Substrate for Sensors Based on Platinum Electrodes

Testing the Performance of the Azo-Polyimide Supramolecular Systems as Substrate for Sensors Based on Platinum Electrodes

The Impact of the Azo-Chromophore Sort on the Features of the Supramolecular Azopolyimide Films Desired to Be Used as Substrates for Flexible Electronics

Polyimide Layers with High Refractivity and Surface Wettability Adapted for Lowering Optical Losses in Solar Cells

Contact Info

Product

Resources

About