Nanocrystalline cellulose

In the work from Liu [105], an eco-friendly superabsorbent based on flax yarn waste for sanitary napkin applications has been successfully prepared. Till now, most of the waste cellulose materials from textile industry, such as cotton linter, cotton yarn waste and flax yarn waste, are still burned or land filled, causing both resource waste and environmental pollution [105, 106]. Reutlllzatlon of these waste materials could not only reduce the consumption of cotton or flax cellulose but also decrease the treatment of industrial waste. The major component [70%] of flax yarn waste is cellulose, which has been introduced as a basic skeleton of superabsorbent in previous studies [105, 106-109]. Fluff pulp, as a good absorbent material, is a kind of special pulp with villiform fibers. Nowadays, it is widely used as raw material for the production of sanitary napkin and paper diaper [105]. 

The objectives of this study were to investigate the preparation of an eco-friendly superabsorbent based on flax yarn waste under different synthesis conditions and to determine the properties of the resulting superabsorbent used for absorbent core layer of sanitary napkins. The results gained from this study strongly suggest that the prepared FYW/PAA superabsorbent has potential application in the field of eco-friendly sanitary napkins as a low-cost and eco-friendly synthetic material [105]. 

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Bai, W. Holbery, J. Li, K. A techinique for production of nanocrystalline cellulose with a narrow size distribution. Cellulose 2009, 16 (3), 455-465. 

Nanocrystalline cellulose, a rod-shaped nanoscale material with exceptional strength and physicochemical properties, can be prepared from inexpensive renewable biomass. Besides its potential use as a reinforcing agent for industrial biocomposites, pristine NCC exhibits low toxicity and poses no serious environmental concerns, providing impetus for its use in bioapplications [115]. 

Applications of functionalized and nanoparticle-modified nanocrystalline cellulose, 30, 283-290. 

Pan, J., Hamad, W., and Straus, S. K. (2010). Parameters affecting the chiral nematic phase of nanocrystalline cellulose films. Macromolecules. 43(8), 3851-3858. 

Beck, S., Bouchard, J., and Berry, R. (2010). Controlling the reflection wavelength of iridescent solid films of nanocrystalline cellulose, Biomacromolecules. 12(1), 167-172. 

Cranston, E.D., Gray, D.G. Morphological and optical characterization of polyelectrol) te multilayers incorporating nanocrystalline cellulose. Biomacromolecules. 7, 2522-2530 (2006b)... 

Derakhshandeh B, Petekidis G, Shaflei-Sabet S et al (2013) Ageing, yielding, and rheology of nanocrystalline cellulose suspensions. J Rheol 57 131-148... 

Kelly JA, Shukaliak AM, Cheung CCY et al (2013) Responsive photonic hydrogels based on nanocrystalline cellulose. Angew Chem 52 8912-8916... 

Cha RT, He ZB, Ni YH (2012) Preparation and characterization of thermal/pH-sensitive hydrogel from carboxylated nanocrystalline cellulose. Carbohydr Polym 88 713-718... 

Peng BL, Han X, Liu HL, Berry RC, Tam KC (2013) Interactions between surfactants and polymer-grafted nanocrystalline cellulose. Colloid Surf A Physicochem Eng Asp... 

There are basically two families of nanosized cellulosic particles (1) Nanofibrillar cellulose, which includes mechanically isolated microfibrils, chemically isolated microfibrils (TEMPO-oxidation), bacterial cellulose and can be considered spaghetti-like, and (2) Cellulose nanocrystals - rods of highly crystalline cellulose which are isolated by acid hydrolysis. Cellulose nanocrystals are represented in literature by synonyms like cellulose whiskers, cellulose nanowhiskers, cellulose microfibrils, micro-crystalline cellulose and nanocrystalline cellulose because they are not yet commercially available. These are needle-shaped (100 run to 200 run X 10 nm), highly crystalline, strong (E - 150 GPa) and form liquid crystal suspensions. 

Different descriptors have been used in the literature to designate the crystalline rod-like nanoparticles. These particles are mainly referred to as whiskers, nanowhiskers, cellulose nanocrystals, NCC (nanocrystalline cellulose), monocrystals, microcrystals, or microcrystallites, despite their nanoscale dimensions. The terms microfibrils, microfibrillated cellulose (MFC), and nanofibrillated cellulose (NFC) are used to designate cellulosic nanoparticles obtained by a simple mechanical shearing disintegration process (Fig. 7.2) as described in the next section. 

Bai W, Holbery J, Li K (2009) A technique for production of nanocrystalline cellulose with a narrow size distribution. Cellulose 16 455-465 Balasubramani M, Kumar TR, Babu M (2001) Skin substitutes a review. Bums 27 534—544 Barud HS, Barrios C, Regiani T et al (2008) Selfsupported silver nanoparticles containing bacterial cellulose membranes. Mater Sci Eng C-Biomim Supramol Syst 28 515-518 Battista OA (1950) Hydrolysis and crystallization of cellulose. Ind Eng Chem 42 502-507 Battista OA, Coppick S, Howsmon JA et al (1956) Level-off degree of polymerization. Relation to polyphase stracture of cellulose fibres. Ind Eng Chem 48 333-335 Beck-Candanedo S, Roman M, Gray DG (2005) Effect of reaction conditions on the properties and behavior of wood cellulose nanocrystal suspensions. Biomacromolecules 6 1048-1054... 

At nanoscale thickness, fibrils are named as nanofibrillar cellulose (NFC) or nanocellulose [26-28]. Highly crystalline cellulose nanowhiskers, also called cellulose micelles, cellulose nanorods, cellulose nanocrystals, or nanocrystalline cellulose are produced under strong acid hydrolysis (e.g., mineral acids such as hydrochloric acid or sulphuric acid) combined with mechanical shearing [22, 29]. 

Tang, Y, Yang, S., Zhang, N., Zhang, J. (2014). Preparation and eharaeterization of nanocrystalline cellulose via low-intensity ultrasonic-assisted sulfuric acid hydrolysis. (1), 335-346. 

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