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Functional coatings with ethyl cellulose-calcium carbonate alkaline nanoparticles for deacidification and mechanical reinforcement of paper artifacts
Matej Bračič, Jasna Malešič, Mihael Brunčko, Doris Bračič, Alenka Ojstršek, Tea Kapun, Sašo Gyergyek, Karin Stana-Kleinschek, Tamilselvan Mohan, 2025, izvirni znanstveni članek

Opis: Paper artifacts susceptible to acid hydrolysis and mechanical stress require effective conservation methods to ensure their longevity. In this study, a novel approach for the deacidification of acidic paper using calcium carbonate (CaCO3) [1,2]-ethylcellulose nanoparticles (CaCO3-EC NPs) dispersed in a non-aqueous ethyl acetate solution is presented. The dispersions were carefully prepared and applied to model acidic paper samples using a dipcoating method and then analyzed for their effectiveness. Transmission electron microscopy showed the formation of agglomerates containing quadrangular alkaline nanoparticles with diameters of 40 to 100 nm and a total agglomerate size of 250 nm. Hydrodynamic analyzes indicate the presence of a swollen ethyl cellulose coating on these agglomerates, which facilitates their dispersion. The results show the effectiveness of the CaCO3-EC NPs system in neutralizing acidic components (change of paper pH from 4.3 to 7) due to the homogeneous distribution within the paper substrates, effectively arresting the degradation processes. Acid-base titration showed a linear correlation between the concentration of alkaline nanoparticles and the alkaline reserve, emphasizing the role of ethylcellulose in facilitating particle transport within the paper matrix. In addition, ethylcellulose was found to improve the mechanical properties of the treated paper, as demonstrated by the standard mechanical tests. Importantly, the optical properties remained unchanged after treatment, as no adverse changes in color were observed. These results underline the effectiveness of the developed deacidification dispersions for the treatment of acidic paper and potentially other cellulose-based cultural heritage documents prone to acidic degradation. This approach offers promising implications for preserving and restoring valuable historical materials.
Ključne besede: ethylcellulose, calcium carbonate, functional coating, deacidification, strengthening, cultural heritage
Objavljeno v DKUM: 20.03.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (184,18 KB)

Grafting of ethylcellulose microcapsules onto cotton fibres
Roxana Badulescu, Vera Vivod, Darja Jaušovec, Bojana Vončina, 2008, izvirni znanstveni članek

Opis: In this paper a treatment of cotton with ethylcellulose (EC) microcapsules wasinvestigated. EC microcapsules containing Rosemary oil were obtained by phase separation method. The surface and morphology of microcapsules were characterized by scanning electron microscopy (SEM). Microcapsules with a regular spherical shape in the 10-90 m size range were prepared and grafted onto cotton using the crosslinking reagent 1,2,3,4-butanetetracarboxylic acid (BTCA) in the presence of catalysts. The influence of the two catalysts, cyanamide (CA) and N,N'-dicyclohexylcarbodiimide (DCC) on curing efficiency (grafting) was investigated. SEM and Fourier transform infrared spectroscopy (FT-IR) were used to study the formation of ester bonds between BTCA and hydroxyl groups of cotton and/or hydroxyl groups of EC. When DCC was used as acatalyst, the esterification took place slowly at room temperature. In the case of CA, the cotton was cured at 110 °C for several minutes. After 2 min curing, the microcapsules, which kept their original shape, were bonded to thecotton fibers. Increasing the curing time altered the microcapsule shell. Grafting and crosslinking reactions of the thermofixed EC microcapsules onto cotton were proposed.
Ključne besede: textiles, chemical modification, cotton fibres, ethylcellulose, microcapsules, BTCA, SEM, FT-IR, grafting
Objavljeno v DKUM: 01.06.2012; Ogledov: 2211; Prenosov: 45
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