Application of ink-jet printing and spray coating for the fabrication of polyaniline/poly(N-vinylpyrrolidone)-based ammonia gas sensor

We report on the preparation of thin conducting films from the poly(N-vinylpyrrolidone) stabilized polyaniline dispersions for the ammonia gas sensor applications. The dispersion is waterbased and prepared by means of relatively simple chemical oxidation polymerization of aniline. Two processes were used for the ink deposition, the ink-jet printing and the spray-coating technique. With the former one, the ink was at first tested on the poly(ethylene terephthalate) foil to find a suitable combination of ink formulation and print parameters. After that, the final ammonia gas sensors were fabricated by both deposition techniques and compared. The aspects of the ink preparation and alteration, as well as the active layer properties, are analyzed by means of UV-vis spectroscopy, optical microscopy, atomic force microscopy, profilometry and electrical measurements. The results obtained from each deposition technique are discussed. In both cases, the sensitivity to the ammonia gas has been demonstrated, making the proposed ink in combination with the two named deposition processes feasible for the potential large-area sensor production

Characterization of polyaniline-based ammonia gas sensors prepared by means of spray coating and ink-jet printing

This work deals with the process of ammonia gas sensor fabrication and its detailed characterization. The sensor active layer was deposited from a polyaniline dispersion. The prepared polyaniline dispersion is based on poly(N-vinylpyrrolidone), acting as a dispersion stabilizer. The dispersion synthesis was tuned towards the printing and coating process. The prepared ink was water-based. The sensor active layer was deposited by means of two different techniques; the ink-jet printing and spray coating. The ink was first optimized using the poly(ethylene terephthalate) foil as the substrate material. The optimal printing parameters and ink properties for the used deposition processes were found. The polyaniline films as well as the performance of fabricated sensors, prepared by means of the both techniques were compared. The polyaniline films were characterized by means of UV-vis spectroscopy, optical microscopy, atomic force microscopy, profilometry and electrical measurements. The differences in the film morphology and aspects of the each of the two used deposition techniques are analyzed and discussed in detail. The sensors obtained from the both techniques showed response to ammonia gas, as well as its concentration. The synthesized ink in combination with the suggested deposition processes could be therefore potentially used for the future manufacturing of the large area ammonia gas sensors. Copyrigh

Electroactive poly(vinylidene fluoride) electrospun fiber mats coated with polyaniline and polypyrrole for tissue regeneration applications

Electrospun membranes with an active response are playing an increasing role in tissue regeneration by improving the ability of the materials to mimic the cellular microenvironment during cell culture. In this context, this work reports on the development of poly(vinylidene fluoride) (PVDF) electrospun fibers coated with polyaniline (PANI) and with polypyrrole (PPy). Both PANI and PPy successfully coated the fibers, with the surface electrical conductivity of the coatings reaching values of =1.19S.m1 for PVDF-PPy and =3.84×103S.m1 for PVDF-PANI. Furthermore, the PVDF samples became hydrophilic upon their coating with either PANI or PPy, the fiber mats adsorbing the water drop after a few seconds. The coated samples remain biocompatible, resulting in a slight improvement in the metabolic activity of L929 fibroblasts.ERDF -European Regional Development Fund(PTDC/BTM-MAT/28237/2017)info:eu-repo/semantics/publishedVersio