1,721,103 research outputs found
Thermal influence on physico-chemical properties of metakaolin/organic-based geopolymers
Full text linkAbstract.
The high amount of organic and inorganic wastes has increased the attention to new strategies aiming to reduce the waste disposals. Among the different technologies, the geopolymers had been proposed as a powerful technology able to incorporate various kind of wastes [1]. Pure metakaolin and a mixture obtained by adding 10% of tomato waste-derived were consolidated by alkali activation at room temperature, 40 and 60°C. FT-IR spectra confirmed the geopolymerization occurrences. Conductivity and pH were evaluated at different time. The integrity tests assessed the resistance of the synthesized geopolymers and the presence of tomato-wastes led to a release of yellow organic hydro-soluble compound. Weight loss confirmed the integrity test, indeed there were no differences at 16 and 30 days. Finally, the antibacterial properties of the synthesized geopolymers were investigated [2].
References
[1] H.K. Tchakouté, C.H. Rüscher, S. Kong, E. Kamseu, C. Leonelli, Constr Build Mater. 2016, 114, 276 – 289
[2] G. Dal Poggetto, M. Catauro, G. Crescente, C. Leonelli, Polymer. 2021, 13, 149
Comparison of fibers in geopolymer matrix for structural reinforcement of masonry (FRGP): compatibility, reactivity, durability
No full textGeopolymer matrix bonded fibre nets of UHTSS-steel, carbon, basalt and AR-glass were
prepared on soft mud bricks. Brick reinforcement was measured by three-point flexural tests and fibrematrix-
substrate adhesion by pull-off tests. The durability of the reinforcements was tested by aging and
freeze-thaw cycles. Alkali resistance of fibres was tested in different alkaline solution and comprised
weight loss and tensile strength
Influence of the addition of waste glass and microbiological performance of metakaolin-based geopolymers cement
Full text linkAbstract.
Glass recycling reduces the amount of waste to be treated or disposed in landfills, allowing both to
limit environmental damage and to save on the costs of transportation and disposal of waste. In this
paper, an advantageous method for recycling glass containers (bottles, jars, jars for food, glasses
and cans for drinks, etc.) is presented. The glass was crushed and without being washed or
separated from any foreign bodies it was safely incorporated into a metakaolin-based geopolymeric
matrix. Pure metakaolin and mixtures obtained by adding different percentages (30-50 wt%) of
glass cullet were consolidated via alkali activation at 50°C. Infrared spectroscopy was able to reveal
the formation of bonds in the mixtures between the geopolymeric matrix and the glass. Leaching
tests were carried out to evaluate the eventual release of toxic metals, while the antibacterial tests
completed the environmental evaluation of the final consolidated products that showed how the
mechanical performance were modified by adding different amount of glass [1].
References
[1] G. Dal Poggetto, M. Catauro, G. Crescente and C. Leonelli. Efficient addiction of waste glass in
MK-based geopolymers: microstructure, antibacterial and cytotoxicity investigation. Polymers,
2021, 13, 1493
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Sintesi assistita da microonde del pigmento CoAl2O4
No full textLa sintesi del pigmento blu CoAl2O4 è stata condotta impiegando il riscaldamento a microonde alla frequenza di 2.45 GHz, utilizzando differenti applicatori (forni). I risultati della sperimentazione mostrano una grande variabilità della resa e del rendimento del processo assistito da microonde dipendentemente dal tipo di forno impiegato e dalla presenza di eventuali materiali ausiliari assorbitori di microonde. L’impiego di applicatori di microonde a modo singolo ha permesso di ottenere il pigmento in condizioni ottimali in tempi inferiori ai 2 minuti, con un consumo energetico specifico misurato di 15 kJ/g. La caratterizzazione mineralogica, colorimetrica e applicativa del pigmento entro impasto per gres porcellanato ha fornito risultati analoghi al pigmento di fabbricazione industriale o ottenuto per calcinazione in forno convenzionale. I risultati ottenuti dimostrano come l’opportuna scelta di applicatore di microonde e materiali di supporto sia fondamentale per massimizzare resa e rendimento del processo
Microwave-Mediated ecofriendly Preparation of bioinorganic layered nanomaterials as new multitasking hybrid systems for cosmetic and pharmaceutical applications
No full text“ECOSUSTAINABLE DEVELOPMENT OF NOVEL MULTITASKING ORGANOCLAYS FOR COSMETIC APPLICATIONS”
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