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206 results on '"Santarelli, Maria Laura"'

9. Bacterial Nanocellulose Hydrogel for the Green Cleaning of Copper Stains from Marble.

Author

Sonaglia, Erica, Schifano, Emily, Sharbaf, Mohammad, Uccelletti, Daniela, Felici, Anna Candida, and Santarelli, Maria Laura

Subjects
HYDROGELS, COPPER, DISCOLORATION, CLEANING, CRYSTALLINITY
Abstract

Cultural heritage stone materials frequently experience significant discoloration induced by copper corrosion products, especially calcareous stones associated with bronze or copper statues and architectural elements. This alteration originates from the corrosion of unprotected copper, resulting in the formation of various Cu minerals and the migration of soluble ions to adjacent stone materials. Traditional cleaning methods involve mechanical, chemical, and laser techniques, which are generally time-consuming, costly, not ecological, or can possibly damage original materials. The loading of highly effective chelating agents, such as ethylenediaminetetraacetic acid (EDTA), into hydrogels has recently been exploited. However, the preference for synthetic hydrogels has been prominent until now, although they lack renewability and biodegradability and require high costs. This study explores for the first time the potential to clean copper corrosion with bacterial nanocellulose (BC) loaded with EDTA as a biologically based, sustainable, and biodegradable hydrogel. The BC hydrogel was characterised by field emission–scanning electron microscopy (FE–SEM), X-ray diffraction analysis (XRD), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), simultaneous thermal analysis (TG-DSC), and tensile testing. It revealed a nano-fibrous structure with high crystallinity and purity and mechanical properties suitable for cultural heritage applications. The EDTA-loaded hydrogel effectively removed copper stains from marble after 120 min of application. Micro-Raman and colorimetric analyses assessed the cleaning efficacy. The study introduces bacterial nanocellulose as a green and effective alternative for heritage conservation, aligning with sustainable methodologies in stone conservation. [ABSTRACT FROM AUTHOR]

Published
2024
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26. Glycerol valorization. Development of selective protocols for acetals production through tailor-made macroreticular acid resins

Author

Marrocchi, Assunta, Trombettoni, Valeria, Campana, Filippo, Passagrilli, Valerio, Nazari, Alireza, Bracciale, Maria Paola, Santarelli, Maria Laura, and Vaccaro, Luigi

Subjects
heterogeneous catalysis, glycerol valorization, Furfural Acetalization, acetalization, biomass transformation, furfural, General Chemistry, Catalysis, Glycerol valorization, Furfural Acetalization, Heterogeneous catalysis, Biomass transformation
Published
2022

27. Scientific investigation on construction materials

Author

Santarelli, Maria Laura, Giorgi, Elisabetta, Ciacchella, MARIA CARLA, and Luisa, Pandolfi

Subjects
analytical investigation, constructive techniques, School of Mathematics, materials
Published
2022

28. Effect of Fibrillated Cellulose on Lime Pastes and Mortars

Author

D’Erme, Chiara, Caseri, Walter Remo, and Santarelli, Maria Laura

Subjects
Technology, Microscopy, QC120-168.85, QH201-278.5, Engineering (General). Civil engineering (General), Article, cellulose, TK1-9971, lime, mortar, fibre reinforced concrete, natural fibres, Descriptive and experimental mechanics, Electrical engineering. Electronics. Nuclear engineering, TA1-2040
Abstract

The use of nanocellulose in traditional lime-based mortars is a promising solution for green buildings in the frame of limiting the CO2 emissions resulting from Portland Cement production. The influence of the fibrillated cellulose (FC) on lime pastes and lime-based mortars was studied incorporating FC at dosages of 0%, 0.1%, 0.2% and 0.3 wt% by weight of binder. The lime pastes were subjected to thermal and nitrogen gas sorption analyses to understand if FC affects the formation of hydraulic compounds and the mesoporosities volume and distribution. The setting and early hydration of the mortars were studied with isothermal calorimetry. The mechanical performances were investigated with compressive and three-point-bending tests. Furthermore, fragments resulting from the mechanical tests were microscopically studied to understand the reinforcement mechanism of the fibres. It was found that 0.3 wt% of FC enhances the flexural and compressive strengths respectively by 57% and 44% while the crack propagation after the material failure is not affected., Materials, 15 (2), ISSN:1996-1944

Published
2022

38. Preliminary study of the mechanical and hygrothermal performance of concrete reinforced with fibrillated cellulose.

Author

D'Erme, Chiara, Verticchio, Elena, Frasca, Francesca, Caseri, Walter, Cornaro, Cristina, Siani, Anna Maria, and Santarelli, Maria Laura

Subjects
REINFORCED concrete, HYGROTHERMOELASTICITY, CELLULOSE fibers, CONSTRUCTION materials, CELLULOSE, CEMENT composites, CEMENT
Abstract

Cement, being the most widely used building material, is the responsible for a large share of greenhouse gas emissions. To reduce the environmental impact of its production, natural fibres can be used as eco-friendly additives. Moreover, their potential use in traditional lime-based mortars makes them an ideal choice for green buildings as well as for the retrofit of historical buildings. An innovative cementitious composite reinforced with fibrillated cellulose (hereafter called «green concrete») was tested to assess its mechanical and physical properties. Samples were casted using Portland cement and natural hydraulic lime and varying the ratios among the constituents. Viscosity and setting time of the fresh pastes were determined with a viscosimeter and a Vicat apparatus, while their hydration was studied by thermal analysis. The influence of the fibres on the flexural strength of the final composite was determined through mechanical tests. The expected hygrothermal performance of the «green concrete» was explored through dynamic hygrothermal simulation to investigate its potential use as a retrofit material. A sensitivity analysis (SA), based on the hygrothermal properties of natural-based building materials similar to the «green concrete», was conducted to identify the parameters influencing more the simulation of annual internal temperature and moisture variations. The preliminary assessment of the mechanical properties of the «green concrete» showed that at higher percentages the cellulose fibres can negatively affect the workability/setting time of the fresh pastes and the flexural strength. The most promising samples were identified and will undergo further investigation. The SA results outlined that the «green concrete» might not be effective for thermal insulation, although it might be used as a moisture-buffering layer by adjusting the values of the free water saturation moisture content, the equilibrium moisture content at RH=80% and the dry vapour diffusion resistance factor of the final composite. [ABSTRACT FROM AUTHOR]

Published
2021
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