Physical, rheological and mechanical properties of alkali activated hydrogels based on nanofibrillated cellulose

Žepič Bogataj, Vesna (author), Oven, Primož (author), Čop, Matjaž (author), Vek, Viljem (author), Janković, Biljana (author), Poljanšek, Ida (author)

Hydrogels are classified as a three-dimensional network system, capable of retaining large amounts of water while preserving their shape and dimensional stability. Due to their natural origin and biocompatibility with human tissue, cellulose nanofibrils are often considered to be promising candidates for bioactive hydrogels preparation. For such applications, their responsiveness under different types of mechanical load, including multiple cyclic compressions, is of crucial importance. In the present study, cellulose nanofibril-based hydrogels were initiated though a simple alkali neutralization treatment. Structural, rheological and compressive features were investigated as a function of elevated NaOH concentration and physical gelling conditions. It was found that a sufficiently concentrated alkaline solution allows the formation of mechanically robust cellulose nanofibril hydrogels, which can be dried to the state of ultralight material, aerogel, of low density (0.057 g cm$^{−3}$), superior porosity (96.2%), super water absorbant capacity (1200%), and exceptional shear and compressive load resilience with elasticity modulus of 9.3 kPa. These outstanding characteristics can be predominantly attributed to the polymorphic conversion of cellulose I to cellulose II, which results from the mercerization of cellulose nanofibrils and creates a stable and firm hydrogels texture.

• Language: English
• Keywords: nanofibrillated cellulose, hydrogel, mercerization, water absorption, compression, shear properties
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty; FFA - Faculty of Pharmacy
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: Str. 16040-16052
• Numbering: Vol. 19, no. 17
• PID: 20.500.12556/RUL-143951
• UDC: 630*8
• ISSN on article: 1544-046X
• DOI: 10.1080/15440478.2022.2123879
• COBISS.SI-ID: 122854147

Note

KLJUČNE BESEDE: absorpcija vode, kompresija, mercerizacija, strižne lastnosti, hidrogel, nanofibrilirana celuloza

• Publication date in RUL: 23.01.2023

Record is a part of a journal

• Title: Journal of natural fibers
• Publisher: Haworth Press
• ISSN: 1544-046X
• COBISS.SI-ID: 521905689

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Chinese

Abstract

水凝胶被分类为三维网络系统, 能够保留大量水, 同时保持其形状和尺寸稳 定性. 由于其天然来源和与人体组织的生物相容性, 纤维素纳米纤维通常被 认为是生物活性水凝胶制备的有前景的候选材料. 对于此类应用, 它们在不 同类型的机械载荷(包括多次循环压缩)下的响应性至关重要. 在本研究中, 通过简单的碱中和处理引发纤维素纳米纤维基水凝胶. 研究了作为提高 NaOH浓度和物理胶凝条件的函数的结构、流变和压缩特性. 发现充分浓缩 的碱性溶液允许形成机械坚固的纤维素纳米纤维水凝胶, 其可干燥至超轻 材料、低密度(0.057 gcm) 气凝胶的状态−3) 具有优异的孔隙率(96.2%)、 超强吸水能力(1200%)以及优异的剪切和压缩载荷弹性, 弹性模量为9.3 kPa. 这些突出的特征主要归因于纤维素I向纤维素II的多晶型转化, 这是纤 维素纳米纤维丝光化的结果, 并产生稳定和牢固的水凝胶纹理.

• Keywords: 纳米原纤化纤维素, 丝光 化, 水凝胶, 吸水率, 压缩, 剪切特性