Comprehensive characterization of hygroscopic, fire‐retardant and thermally insulating sulfated nanocellulose aerogel

Jaouahar, Mohamed (author), Hanani, Zouhair (author), Ablouh, El-Houssaine (author), Humar, Miha (author), El Achaby, Mounir (author), Sehaqui, Houssine (author)

Nanocellulose aerogel is an interesting class of materials that combines lightweight, high porosity, and exceptional insulating properties of aerogels with abundance, renewability, and biodegradability of cellulose. These eco-friendly materials are highly desirable in insulation applications to replace petroleum-based counterparts, thus responding to major global challenges related to climate change and resources depletion. Herein, a nanocellulose aerogel with sulfate moieties (S-NC), is prepared via functionalization of cellulose in H2SO4 /urea, followed by mechanical defibrillation and freeze-drying processes. Advanced techniques such as static and dynamic compression tests, SEM, DVS, TG-MS, XPS, and micro combustion calorimetry were used to assess S-NC characteristics and comprehend its thermal behavior. As a result of its ultra-high porosity (99.3 %), and its sulfate-half ester functional groups, the S-NC aerogel exhibits both a low thermal conductivity of 26 mW.(m·K)-1 and a pronounced flame-retardant behavior. The total heat release registered by microscale combustion calorimetry analysis is only 1.68 kJ.g−1 for the S-NC aerogel. In addition, the hygroscopicity of the aerogel was evaluated via water vapor sorption analysis and fitted to the Guggenheim-Anderson-de Boer (GAB) model, revealing a type II sorption mechanism with moisture buffering capacity of 0.63 g/g S-NC at 95 % relative humidity. The S-NC aerogel is eco-friendly material combining moisture adsorption with flame retardancy and thermal insulation, properties that are critical for safety and performance in applications vulnerable to heat and fire risks.

• Language: English
• Keywords: sulfated nanocellulose, aerogel, flame-retardancy, thermal insulation, moisture adsorption
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 12 str.
• Numbering: Vol. 506, [article no.] ǂ160236
• PID: 20.500.12556/RUL-167115
• UDC: 630*8
• ISSN on article: 1873-3212
• DOI: 10.1016/j.cej.2025.160236
• COBISS.SI-ID: 225593347
• Publication date in RUL: 10.02.2025

Record is a part of a journal

• Title: Chemical engineering journal
• Publisher: Elsevier
• ISSN: 1873-3212
• COBISS.SI-ID: 23123973

Secondary language

• Language: Slovenian
• Keywords: sulfatirana nanoceluloza, ognjevarnost, toplotna izolacija, adsorpcija vlage