Application of silane grafted titanate nanotubes in reinforcing of polyamide 11 composites

Polyamide 11 (PA11) composites reinforced with pristine and silanized titanate nanotubes (TTNT) were prepared using twin-screw melt compounding. A better dispersion of silanized TTNT in PA11 caused increase of crystallinity and decrease of the long period of PA11 lamellar structure. The increase of glass transition (∼33%) and decomposition temperature (∼3%), as well as, the improvement of Young's, storage and loss modulus (of 17, 27 and 17% respectively) was achieved in the composites loaded with the highest content (2 wt%) of nanofiller silanized by 3-aminopropyltriethoxysilane (APTES), owning to a chemical interaction established at the silanized TTNT-PA11 interface. Contrary to it, lack of compatibility at the pristine TTNT-PA11 interface led to drop (up to 20%) in the strength at break in these composites

Asynchronous automata networks can emulate any synchronous automata network

Electronic version of an article published as International Journal of Algebra and Computation 2004 Vol. 14 no.5-6 pp.719-739 DOI: 10.1142/S0218196704002043 copyright World Scientific Publishing Company http://ejournals.wspc.com.sg/journals/ijac/mkt/archive.shtml DOI : 10.1142/S0218196704002043Peer reviewe

Bionanocomposite Bamboo: A Regioselective Impregnation with Silver Nanofillers for Antifungal Application

Silver nanoparticles are promising nanofiller materials (Ag-NFs) for reinforcement and anti-bacterial effect in polymers and composites. In this investigation bamboo Dendrocalamus giganteus Munro specimens were impregnated using a colloidal solution of homemade Ag-NFs with the objective of filling up the vascular bundles vessels and improving its resistance to fungi attacks. The metal nanostructured materials with different charged organic ligands (trisodium citrate and chitosan) were used to fill up the internal microenvironment of bamboo. Chemical and physical characterization was made by DLS, UV-VIS, zeta-potential and STEM. The bamboo specimens (5x12x18mm) were submitted to 20 impregnation cycles through a vacuum system. A qualitative characterization of the metal aggregate depositions of impregnated bamboo specimens were analyzed with X-ray microtomography (mu CT) revealing a gradient deposition of citrate-capped Ag-NFs into the parenchyma tissue with higher concentration at the outer part for bamboo, while the chitosancapped Ag-NFs were deposited mainly in the vessel bundles. Both engineered bionanocomposite materials when exposed to air and humidity, after 14 months, the samples were free of fungal colonies, while colonization by the fungal hyphae were present in untreated bamboo specimens