Preparation of photoreactive nanocellulosic materials via benzophenone grafting

Orelma, Hannes; Vuoriluoto, Maija; Johansson, Leena‐Sisko; Campbell, J.M.; Filpponen, Ilari; Biesalski, Markus; Rojas, Orlando J.

doi:10.1039/c6ra15015b

Cited by 28 publications

(27 citation statements)

References 27 publications

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“…Oxidative treatments (e.g., TEMPO-oxidation, [68,73,79] hydrolysis with dicarboxylic acids, [80,81] carboxymethylation [82,83] ) are an exception here. They introduce surface carboxyls, which facilitate covalent, [84,85] and noncovalent, [86,87] modification (4, 5 in Figure 3a). The directionality of native cellulose provides additional synthetic freedom: nanocelluloses bear aldehyde (hemiacetal) groups exclusively on one end, [88] allowing topochemical modifications-a recently emerging trend in the realm of material concepts for CNCs.…”

Section: Advances In Chemical Modificationmentioning

confidence: 99%

Nanocellulose: Recent Fundamental Advances and Emerging Biological and Biomimicking Applications

et al. 2020

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In the effort toward sustainable advanced functional materials, nanocelluloses have attracted extensive recent attention. Nanocelluloses range from rod‐like highly crystalline cellulose nanocrystals to longer and more entangled cellulose nanofibers, earlier denoted also as microfibrillated celluloses and bacterial cellulose. In recent years, they have spurred research toward a wide range of applications, ranging from nanocomposites, viscosity modifiers, films, barrier layers, fibers, structural color, gels, aerogels and foams, and energy applications, until filtering membranes, to name a few. Still, nanocelluloses continue to show surprisingly high challenges to master their interactions and tailorability to allow well‐controlled assemblies for functional materials. Rather than trying to review the already extensive nanocellulose literature at large, here selected aspects of the recent progress are the focus. Water interactions, which are central for processing for the functional properties, are discussed first. Then advanced hybrid gels toward (multi)stimuli responses, shape‐memory materials, self‐healing, adhesion and gluing, biological scaffolding, and forensic applications are discussed. Finally, composite fibers are discussed, as well as nanocellulose as a strategy for improvement of photosynthesis‐based chemicals production. In summary, selected perspectives toward new directions for sustainable high‐tech functional materials science based on nanocelluloses are described.

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Section: Advances In Chemical Modificationmentioning

confidence: 99%

Nanocellulose: Recent Fundamental Advances and Emerging Biological and Biomimicking Applications

et al. 2020

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“…The TEMPO-oxidation of the cellulose fibers was made following the procedure described elsewhere [75][76][77][78][79] . In particular, the procedure reported by Orelma et al 80 has been followed, starting from milled and sieved 45g cellulose. The original pulp hard sheets were milled using a Wiley mill with a 1 mm sieve; the pulp was then oven-dried to a constant weight at 105°C.…”

Section: Methodsmentioning

confidence: 99%

Coaxial Spinning of All-Cellulose Systems for Enhanced Toughness: Filaments of Oxidized Nanofibrils Sheathed in Cellulose II Regenerated from a Protic Ionic Liquid

et al. 2020

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Hydrogels of TEMPO-oxidized nanocellulose (TO-CNF) were stabilized for dry-jet wet spinning using a shell of cellulose dissolved in 1,5-diazabicyclo[4.3.0]non-5-enium propionate ([DBNH][CO2Et]), a protic ionic liquid (PIL). Coagulation in an acidic water bath resulted in continuous core-shell filaments (CSF) that were tough and flexible: average dry (and wet) toughness of ~11 (2) MJ . m -3 and elongation of ~9 ( 14) %. CSF morphology, chemical composition, thermal stability, crystallinity, and bacterial activity were assessed using scanning electron microscopy with energy dispersive X-ray spectroscopy, liquid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, pyrolysis gas chromatography-mass spectrometry, wide angle X-ray scattering and bacterial cell culturing, respectively. The coaxial wet spinning yields PIL-free systems carrying on the surface the cellulose II polymorph, which not only enhances the toughness of the filaments but facilities their functionalization.apply a strategy based on the principles of the circular economy. Bio-based materials and, in particular, cellulose nanomaterials (CNMs) have become excellent candidates in this regard, as they could partially replace materials based on non-renewable resources. Indeed, CNMs enable high-performance, green functional materials with a broad spectrum of applications, e.g., electronics, biomedical and tissue engineering scaffolds, coatings, food, textiles, and even in daily use goods [1][2][3][4][5][6][7][8] .Cellulose resources have the potential of becoming a platform to develop novel CNMs with high mechanical performance since nanocellulose, in its cellulose I crystalline phase, possess an elastic modulus of about 150 GPa and 18-50GPa in the longitudinal and transverse directions, respectively 9,10 . The regioselective C6 oxidation of nanocellulose fibers can be additionally catalyzed by the use of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) nitroxyl radical to produce hydrogels with high transparency 11 , an extensive degree of fibrillation 12 , and low cytotoxicity 13 . These TEMPO-oxidized cellulose nanofibers (TO-CNF) are suitable for applications in diverse fields such as packaging 3,4,[14][15][16] , textiles [17][18][19][20] , biosensing and bioelectronics 21,22 , fire retardancy 23 , wound dressing and cell delivery [24][25][26] , among others 3 . Despite its excellent mechanical properties, materials derived from nanocellulose and, in particular, TEMPO-oxidized nanocellulose, have several drawbacks inherent to its nature. For instance, these materials are mostly hydrophilic owing to the high concentration of hydroxyl and carboxylate groups; this causes mechanical instability of the formed materials under wet/humid conditions, and exhibit rather low aspect ratios compared to dissolved polymers. The limited aspect ratio makes it difficult to create oriented structures of cellulose nanofibrils by drawing 27,28 . Many attempts to overcome hydrophilicity challenges have been made through appr...

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“…First, an aqueous dispersion of 2% solid content was prepared followed by fibrillation through a high-pressure M-110 P fluidizer (Microfluidics corp. Newton, MA, U.S.A.) for 6 passes. The method for tempo-oxidized cellulose nanofibril (TOCNF) preparation is detailed in our previous report . Purified chitin flakes from shrimp shells, with the degree of acetylation (DA) of ∼72%, were purchased from Sigma-Aldrich.…”

Section: Methodsmentioning

confidence: 99%

Nanocellulose and Nanochitin Cryogels Improve the Efficiency of Dye Solar Cells

Poskela

Miettunen

Borghei

et al. 2019

ACS Sustainable Chem. Eng.

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Biobased cryogel membranes were applied as electrolyte holders in dye solar cells (DSC) while facilitating carrier transport during operation. They also improved device performance and stability. For this purpose, cellulose nanofibers (CNF), TEMPO-oxidized CNF (TOCNF), bacterial cellulose (BC), and chitin nanofibers (ChNF) were investigated. The proposed materials and protocols for incorporating the electrolyte, via simple casting, avoided the typical problems associated with injection of the electrolyte through filling holes, a major difficulty especially in manufacturing large area cells. Owing to the fact that cryogel membranes did not require any orifice for injection, they were effective in minimizing leakage and in retaining liquid electrolyte. The results indicated the reduction of performance losses compared to conventional electrolyte filling, likely due to the better spatial distribution of electrolyte. DSCs based on BC cryogels had an initially higher performance and similar stability compared to those of the reference cells. When compared to reference cells, CNF and ChNF cryogels produced higher initial performance, but they underwent a faster degradation. The difference in stability was attributed to the effect of residual components, including lignin in CNF and proteins in ChNF, as demonstrated in bleaching experiments. TOCNF indicated a relatively poor performance, most likely because of residual aldehydes. Overall, we offer a comprehensive evaluation based on current−voltage (IV) profiles under simulated sunlight, incident photon-to-charge carrier efficiency (IPCE), electrochemical impedance spectroscopy (EIS), and color image processing, together with accelerated DSC stability tests, to unveil the effects of new membrane-based assembly. Our results give guidelines for future developments related in particular to the effects of the tested biomaterials on device stability.

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Preparation of photoreactive nanocellulosic materials via benzophenone grafting

Abstract: A method for preparing photo-crosslinkable cellulose nanofibrils (CNF) was investigated.

Cited by 28 publications

References 27 publications

Nanocellulose: Recent Fundamental Advances and Emerging Biological and Biomimicking Applications

Nanocellulose: Recent Fundamental Advances and Emerging Biological and Biomimicking Applications

Coaxial Spinning of All-Cellulose Systems for Enhanced Toughness: Filaments of Oxidized Nanofibrils Sheathed in Cellulose II Regenerated from a Protic Ionic Liquid

Nanocellulose and Nanochitin Cryogels Improve the Efficiency of Dye Solar Cells

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