Guilherme Barra

Prof. Guilherme Barra


Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2011 in Polymer Testing
Verified
Journal Article
Closed access
CMClaudia Merlini
Claudia Merlini
VSValdir Soldi
Valdir Soldi
GBGuilherme Barra
Guilherme Barra

1 January 2011 in Synthetic Metals
Verified
Journal Article
Closed access
DMD. Müller
D. Müller
CRC.R. Rambo
C.R. Rambo
DDDerce O S D.O.S.Recouvreux
Derce O S D.O.S.Recouvreux
LPL.M. Porto
L.M. Porto
GBGuilherme Barra
Guilherme Barra

1 March 2006 in European Polymer Journal
Verified
Journal Article
Closed access
BSBluma G Soares
Bluma G Soares
MLMaria Elena Leyva
Maria Elena Leyva
GBGuilherme Barra
Guilherme Barra
DKDipak Khastgir
Dipak Khastgir

1 February 2013 in Polymer International
Verified
Journal Article
Closed access
PDF file
SRSílvia DAS Ramôa
Sílvia DAS Ramôa
GBGuilherme Barra
Guilherme Barra
RORicardo Vb Oliveira
Ricardo Vb Oliveira
MOMarcia Oliveira
Marcia Oliveira
MCMateus Cossa
Mateus Cossa
BSBluma G Soares
Bluma G Soares

1 August 2012 in Cellulose
Verified
Journal Article
Closed access
PDF file
DMD. Müller
D. Müller
JMJ. S. Mandelli
J. S. Mandelli
JMJ. A. Marins
J. A. Marins
BSBluma G Soares
Bluma G Soares
LPL. M. Porto
L. M. Porto
GBGuilherme Barra
Guilherme Barra

17 March 2014 in RSC Advances
Verified
Journal Article
Closed access
PDF file
CMC. Merlini
C. Merlini
GBGuilherme Barra
Guilherme Barra
TAT. Medeiros Araujo
T. Medeiros Araujo
Alessandro PegorettiAlessandro Pegoretti
Alessandro Pegoretti
Non-woven mats with highly pressure-sensitive electrical conductivity have been prepared by electrospinning of poly(vinylidene fluoride) (PVDF) containing up to 23 wt% of polypyrrole (PPy) particles synthesized by using dodecylbenzenesulfonic acid (DBSA) as a dopant. The obtained mats have been characterized by dynamic mechanical thermal analysis, differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, scanning electron microscopy and nitrogen adsorption BET. Electrical resistivity changes of PVDF/PPy blends were investigated during loading–unloading compressive cycles. It has been observed that the electrical resistivity varies reversibly with the applied compressive stress. The maximum sensitivity was obtained for a PVDF/PPy blend containing 13 wt% of PPy, manifesting an electrical resistivity drop of 10 orders of magnitude, i.e. from 1017 to 107 Ω cm upon application of a compressive stress of 5 MPa. This peculiar response can be attributed to the formation of stress-induced conducting pathways in the electrospun network. Considering the remarkable resistivity change and the reproducibility of the phenomenon after repeated loading–unloading cycles, this mat may find application as a pressure sensor.