2 research outputs found
Effect of vegetable oils in limewashes for protection of masonry facades
Lime coatings have been used on architectural surfaces all over the world since ancient times.
Additives have been used to improve specific properties of the coatings in relation to the substrate and
environment where they were applied. They can impart lime coatings water-repellent properties to pro-
tect surfaces from degradation, salt dissolutions, and microorganisms. But with the development of new
synthetic materials after the Industrial Revolution, these techniques fell into disuse.
This work focuses on evaluating the compatibility of vegetable oil additives with limewash paints
on porous substrates by assessing the wettability and drying behavior of the coatings. These traditional
and eco-friendly additives can be used as an alternative sustainable material as opposed to synthetic
additives. In this study, three different vegetable oil additives were used: rapeseed oil, sunflower oil
and high oleic sunflower oil. Additionally, a commercial water-repellent lime putty with the addition
of olive oil sub-product was used to prepare a limewash (Fradical limewash) and compare it to the oil
lab-prepared limewashes. The limewashes were applied to two different stones with different porous
structures: Mšené stone, with high porosity and pore size distribution, and Opuka stone, with lower
porosity and much smaller pore size than the previous stone.
The lime coatings performance was evaluated by measuring the water contact angle, water ab-
sorption by capillarity, and drying behavior with water and salt solution.
The limewash that showed the best water-repellence, less water absorption and fastest drying
with pure water was the Fradical limewash. The rapeseed limewash showed the fastest drying with the
salt solution on Opuka and also showed promising results in the contact angle test being the only one
that showed good water-resistance among the vegetable oil-based additives lab-prepared limewashes.
The sunflower oil limewash had the fastest drying with the salt solution on Mšené stone.Revestimentos de cal têm sido usados sobre superfícies arquitetónicas em todo o mundo desde
os tempos antigos. Os aditivos têm sido utilizados para melhorar propriedades específicas dos revesti-
mentos em relação ao substrato e ao ambiente onde foram aplicados. Podem conferir propriedades hi-
drófobas aos revestimentos de cal, protegendo as superfícies da degradação, dissoluções de sais e mi-
crorganismos. Mas com o desenvolvimento de novos materiais sintéticos após a Revolução Industrial,
essas técnicas caíram em desuso.
Este trabalho tem como foco avaliar a compatibilidade de aditivos de óleos vegetais com tintas
de cal em substratos porosos, avaliando o humedecimento e o comportamento de secagem dos materi-
ais. Esses aditivos tradicionais e ecologicamente verdes podem ser usados como material alternativo e
sustentável, ao contrário de aditivos sintéticos. Neste estudo, foram utilizados três aditivos diferentes
de óleo vegetal: óleo de colza, óleo de girassol e óleo de girassol com alto teor oleico. Além disso foi
utilizada, uma cal hidratada hidrófuga comercial, produzida com adição de subproduto de azeite para
preparar um leito de cal (leite de cal Fradical) e comparar com as caiações com óleo preparadas em
laboratório. A caiação foi aplicada em duas pedras diferentes com estruturas porosas muito distintas: a
pedra Mšené com alta porosidade e de tamanho de poros, e a pedra Opuka, com porosidade menor e
com tamanho de poros muito menor que a pedra anterior.
O desempenho destes revestimentos de cal foram avaliados medindo-se o ângulo de contacto de
gota de água, a absorção de água por capilaridade e o comportamento de secagem com água e solução
salina.
O leite de cal que apresentou melhor repelência à água, menor absorção de água, secagem mais
rápida com água foi o leite de cal Fradical. O leite de cal de óleo de colza apresentou a secagem mais
rápida com solução salina na pedra Opuka e também apresentou resultados promissores no ensaio de
ângulo de contacto sendo a única que apresentou boa resistência à água entre as caiações de aditivos
com óleo vegetal preparadas em laboratório. O leite de cal com óleo de girassol teve a secagem mais
rápida com a solução salina na pedra Mšené
BacHBerry: BACterial Hosts for production of Bioactive phenolics from bERRY fruits
BACterial Hosts for production of Bioactive phenolics from bERRY fruits (BacHBerry) was a 3-year project funded by the Seventh Framework Programme (FP7) of the European Union that ran between November 2013 and October 2016. The overall aim of the project was to establish a sustainable and economically-feasible strategy for the production of novel high-value phenolic compounds isolated from berry fruits using bacterial platforms. The project aimed at covering all stages of the discovery and pre-commercialization process, including berry collection, screening and characterization of their bioactive components, identification and functional characterization of the corresponding biosynthetic pathways, and construction of Gram-positive bacterial cell factories producing phenolic compounds. Further activities included optimization of polyphenol extraction methods from bacterial cultures, scale-up of production by fermentation up to pilot scale, as well as societal and economic analyses of the processes. This review article summarizes some of the key findings obtained throughout the duration of the project