Abstract
In the field of cellulose nanofibers (CNF), the determination of their nano-scale fibre diameters is crucial for characterising the material and helping end-users compare different products available on the market. Yet, measuring CNF diameters from microscopy images is often a tedious task due to the limited field of view at high magnification, high fibre counts and complex entanglement of fibre networks. In this work, the effect of measuring all fibres in an entire image, 100 representative fibres in an image and all fibres in a reduced area of an image were investigated. Two CNF samples were analysed: a coarser more heterogeneous fibre sample and a finer more homogeneous fibre sample. Four high magnification images were analysed per sample. Different people (operators) were given the same task of measuring the fibres to study the effect of operator bias. All fibres from all images were first measured by Operator 1 (main operator) to determine the baseline distribution. Operators 2 and 3 were tasked with selecting and measuring 100 representative fibres from each image. The results showed that when the operators were asked to select fibres, they showed consistent bias towards larger fibres thus rendering the results unreliable. A more promising approach was found when Operators 2 and 3 analysed all fibres within a reduced area within an image. This showed a maximum deviation from the baseline fibre diameter distribution of 9 nm for the coarser more heterogeneous sample and 2 nm for the finer more homogeneous sample. Statistical analysis showed that approximately 150 fibres needed to be measured in order to obtain representative results, provided all fibres within the selected area were measured. Kruskal–Wallis statistical testing also showed that the technique of measuring all fibres in a reduced area of an SEM image yielded more representative results to the baseline distribution compared to the technique of measuring 100 representative fibres. The results here provide the foundation for future accurate measurements of CNF diameter distributions.
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References
Abe K, Yano H (2009) Comparison of the characteristics of cellulose microfibril aggregates of wood, rice straw and potato tuber. Cellulose 16:1017–1023. https://doi.org/10.1007/s10570-009-9334-9
Alemdar A, Sain M (2008) Biocomposites from wheat straw nanofibers: Morphology, thermal and mechanical properties. Compos Sci Technol 68:557–565. https://doi.org/10.1016/j.compscitech.2007.05.044
Ang S, Haritos V, Batchelor W (2019) Effect of refining and homogenization on nanocellulose fiber development, sheet strength and energy consumption. Cellulose 26:4767–4786. https://doi.org/10.1007/s10570-019-02400-5
Baati R, Mabrouk AB, Magnin A, Boufi S (2018) CNFs from twin screw extrusion and high pressure homogenization: a comparative study. Carbohydr Polym 195:321–328. https://doi.org/10.1016/j.carbpol.2018.04.104
Bhatnagar A, Sain M (2005) Processing of cellulose nanofiber-reinforced composites. J Reinf Plast Compos 24:1259–1268. https://doi.org/10.1177/0731684405049864
Chaker A, Alila S, Mutjé P, Vilar MR, Boufi S (2013) Key role of the hemicellulose content and the cell morphology on the nanofibrillation effectiveness of cellulose pulps. Cellulose 20:2863–2875. https://doi.org/10.1007/s10570-013-0036-y
Chen JH, Liu JG, Su YQ, Xu ZH, Li MC, Ying RF, Wu JQ (2019) Preparation and properties of microfibrillated cellulose with different carboxyethyl content. Carbohydr Polym 206:616–624. https://doi.org/10.1016/j.carbpol.2018.11.024
Delgado-Aguilar M, González I, Tarrés Q, Pèlach MT, Alcalà M, Mutjé P (2016) The key role of lignin in the production of low-cost lignocellulosic nanofibres for papermaking applications. Ind Crops Prod 86:295–300. https://doi.org/10.1016/j.indcrop.2016.04.010
Dimic-Misic K, Maloney T, Gane P (2018) Effect of fibril length, aspect ratio and surface charge on ultralow shear-induced structuring in micro and nanofibrillated cellulose aqueous suspensions. Cellulose 25:117–136. https://doi.org/10.1007/s10570-017-1584-3
Ding Q, Zeng J, Wang B, Tang D, Chen K, Gao W (2019) Effect of nanocellulose fiber hornification on water fraction characteristics and hydroxyl accessibility during dehydration. Carbohydr Polym 207:44–51. https://doi.org/10.1016/j.carbpol.2018.11.075
Diop CIK, Tajvidi M, Bilodeau MA, Bousfield DW, Hunt JF (2017) Isolation of lignocellulose nanofibrils (LCNF) and application as adhesive replacement in wood composites: example of fiberboard. Cellulose 24:3037–3050. https://doi.org/10.1007/s10570-017-1320-z
Errokh A, Magnin A, Putaux JL, Boufi S (2018) Morphology of the nanocellulose produced by periodate oxidation and reductive treatment of cellulose fibers. Cellulose 25:3899–3911. https://doi.org/10.1007/s10570-018-1871-7
Habibi Y, Mahrouz M, Vignon MR (2009) Microfibrillated cellulose from the peel of prickly pear fruits. Food Chem 115:423–429. https://doi.org/10.1016/j.foodchem.2008.12.034
Henriksson M, Berglund LA, Isaksson P, Lindström T, Nishino T (2008) Cellulose nanopaper structures of high toughness. Biomacromolecules 9:1579–1585. https://doi.org/10.1021/bm800038n
Hotaling NA, Bharti K, Kriel H, Simon CG Jr (2015) DiameterJ: a validated open source nanofiber diameter measurement tool. Biomaterials 61:327–338
Isogai A (2013) Wood nanocelluloses: fundamentals and applications as new bio-based nanomaterials. J Wood Sci 59:449–459. https://doi.org/10.1007/s10086-013-1365-z
Iwamoto S, Nakagaito AN, Yano H (2007) Nano-fibrillation of pulp fibers for the processing of transparent nanocomposites. Appl Phys A Mater Sci Process 89:461–466. https://doi.org/10.1007/s00339-007-4175-6
Jiang E et al (2017) Cellulose nanofibers as rheology modifiers and enhancers of carbonization efficiency in polyacrylonitrile. ACS Sustain Chem Eng 5:3296–3304. https://doi.org/10.1021/acssuschemeng.6b03144
Kangas H, Lahtinen P, Sneck A, Saariaho A-M, Laitinen O, Hellen E (2014) Characterization of fibrillated celluloses. A short review and evaluation of characteristics with a combination of methods. Nord Pulp Paper Res J 29:129–143
Karande VS, Bharimalla AK, Hadge GB, Mhaske ST, Vigneshwaran N (2011) Nanofibrillation of cotton fibers by disc refiner and its characterization. Fibers Polym 12:399–404. https://doi.org/10.1007/s12221-011-0399-3
Mandal A, Chakrabarty D (2011) Isolation of nanocellulose from waste sugarcane bagasse (SCB) and its characterization. Carbohydr Polym 86:1291–1299. https://doi.org/10.1016/j.carbpol.2011.06.030
McDonald JH (2009) Handbook of biological statistics, vol 2. Sparky house publishing, Baltimore
Osong SH, Norgren S, Engstrand P (2016) Processing of wood-based microfibrillated cellulose and nanofibrillated cellulose, and applications relating to papermaking: a review. Cellulose 23:93–123. https://doi.org/10.1007/s10570-015-0798-5
Raj P, Mayahi A, Lahtinen P, Varanasi S, Garnier G, Martin D, Batchelor W (2016) Gel point as a measure of cellulose nanofibre quality and feedstock development with mechanical energy. Cellulose 23:3051–3064. https://doi.org/10.1007/s10570-016-1039-2
Santucci BS, Bras J, Belgacem MN, Curvelo AADS, Pimenta MTB (2016) Evaluation of the effects of chemical composition and refining treatments on the properties of nanofibrillated cellulose films from sugarcane bagasse. Ind Crops Prod 91:238–248. https://doi.org/10.1016/j.indcrop.2016.07.017
Shanmugam K, Doosthosseini H, Varanasi S, Garnier G, Batchelor W (2018) Flexible spray coating process for smooth nanocellulose film production. Cellulose 25:1725–1741. https://doi.org/10.1007/s10570-018-1677-7
Siró I, Plackett D, Hedenqvist M, Ankerfors M, Lindström T (2011) Highly transparent films from carboxymethylated microfibrillated cellulose: the effect of multiple homogenization steps on key properties. J Appl Polym Sci 119:2652–2660. https://doi.org/10.1002/app.32831
Spence KL, Venditti RA, Habibi Y, Rojas OJ, Pawlak JJ (2010) The effect of chemical composition on microfibrillar cellulose films from wood pulps: mechanical processing and physical properties. Bioresour Technol 101:5961–5968. https://doi.org/10.1016/j.biortech.2010.02.104
Taheri H, Samyn P (2016) Effect of homogenization (microfluidization) process parameters in mechanical production of micro- and nanofibrillated cellulose on its rheological and morphological properties. Cellulose 23:1221–1238. https://doi.org/10.1007/s10570-016-0866-5
Taniguchi T, Okamura K (1998) New films produced from microfibrillated natural fibres. Polym Int 47:291–294. https://doi.org/10.1002/(SICI)1097-0126(199811)47:3%3c291:AID-PI11%3e3.0.CO;2-1
Varanasi S, He R, Batchelor W (2013) Estimation of cellulose nanofibre aspect ratio from measurements of fibre suspension gel point. Cellulose 20:1885–1896. https://doi.org/10.1007/s10570-013-9972-9
Wang B, Sain M (2007) Isolation of nanofibers from soybean source and their reinforcing capability on synthetic polymers. Compos Sci Technol 67:2521–2527. https://doi.org/10.1016/j.compscitech.2006.12.015
Wang QQ, Zhu JY, Gleisner R, Kuster TA, Baxa U, McNeil SE (2012) Morphological development of cellulose fibrils of a bleached eucalyptus pulp by mechanical fibrillation. Cellulose 19:1631–1643. https://doi.org/10.1007/s10570-012-9745-x
Zhang L, Batchelor W, Varanasi S, Tsuzuki T, Wang X (2012) Effect of cellulose nanofiber dimensions on sheet forming through filtration. Cellulose 19:561–574. https://doi.org/10.1007/s10570-011-9641-9
Acknowledgments
The authors wish to thank Australian Paper Maryvale for their ongoing support with the project. The authors wish to acknowledge the Monash Centre of Electron Microscopy (MCEM) for use of their SEM facilities. Shaun Ang would like to thank the Australian Government for a Research Training Program scholarship.
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Ang, S., Narayanan, J.R., Kargupta, W. et al. Cellulose nanofiber diameter distributions from microscopy image analysis: effect of measurement statistics and operator. Cellulose 27, 4189–4208 (2020). https://doi.org/10.1007/s10570-020-03058-0
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DOI: https://doi.org/10.1007/s10570-020-03058-0