resumo
In recent years, the synthesis of polymer electrolyte systems derived from biopolymers for the development of sustainable green electrochemical devices has attracted great attention. Here electrolytes based on the red seaweeds-derived polysaccharide kappa-carrageenan (kappa-Cg) doped with neodymium triflate (NdTrif(3)) and glycerol (Gly) were obtained by means of a simple, clean, fast, and low-cost procedure. The aim was to produce near-infrared (NIR)-emitting materials with improved thermal and mechanical properties, and enhanced ionic conductivity. Cg has a particular interest, due to the fact that it is a renewable, cost-effective natural polymer and has the ability of gelling in the presence of certain alkali- and alkaline-earth metal cations, being good candidates as host matrices for accommodating guest cations. The as-synthesised kappa-Cg-based membranes are semi-crystalline, reveal essentially a homogeneous texture, and exhibit ionic conductivity values 1-2 orders of magnitude higher than those of the kappa-Cg matrix. A maximum ionic conductivity was achieved for 50 wt.% Gly/kappa-Cg and 20 wt.% NdTrif(3)/kappa-Cg (1.03 x 10(-4), 3.03 x 10(-4), and 1.69 x 10(-4) S cm(-1) at 30, 60, and 97 degrees C, respectively). The NdTrif-based kappa-Cg membranes are multi-wavelength emitters from the ultraviolet (UV)/visible to the NIR regions, due to the kappa-Cg intrinsic emission and to Nd3+, F-4(3/2)-> I-4(11/2-9/2).
palavras-chave
IOTA-CARRAGEENAN; POLYMER ELECTROLYTE; GEL ELECTROLYTE; SMART WINDOWS; BIOPOLYMER; CONDUCTIVITY; CHITOSAN; TRANSITION; DEVICES
categoria
Biochemistry & Molecular Biology; Chemistry
autores
Nunes, SC; Saraiva, SM; Pereira, RFP; Silva, MM; Carlos, LD; Almeida, P; Goncalves, MC; Ferreira, RAS; Bermudez, VD
nossos autores
Luís Carlos
Professor Catedrático
Maria Rute de Amorim e Sá Ferreira André
Professor CatedráticoProjectos
Luminescent electrochromic devices incorporating organic/inorganic (bio)hybrid electrolytes (LUMECD)
agradecimentos
This research was funded by National Funds by Foundation for Science and Technology (FCT) and by FEDER funds through the POCI-COMPETE 2020 - Operational Programme Competitiveness and Internationalisation in Axis I - Strengthening research, technological development and innovation (FCOMP-01-0124-FEDER-037271, Pest-OE/QUI/UI0616/2014 and UID/CTM/50025/2013), project LUMECD (POCI-01-0145-FEDER-016884 and PTDC/CTM-NAN/0956/2014), project UniRCell (SAICTPAC/0032/2015, POCI-01-0145-FEDER-016422)), and by the Portuguese National NMR Network (RNRMN). S. C. Nunes was funded by FCT projects (Post-PhD Fellowships of UniRCell and LUMECD projects). The R. F. P. Pereira was funded by FCT (SFRH/BPD/87759/2012 grant).