Study of the lignin model compound supramolecular structure by combination of near-field scanning optical microscopy and atomic force microscopy

Mićić, Miodrag; Radotić, Ksenija; Jeremić, Milorad; Djikanović, Daniela; Kämmer, Stefan

doi:10.1016/j.colsurfb.2003.10.018

Cited by 38 publications

(27 citation statements)

References 41 publications

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“…Therefore, one might expect guaiacyl-syringyl lignins of angiosperms to display more coiled spiral conformation with a greater longitudinal expansion relative to gymnosperm lignins, which have a higher content of β-β and β-5 bonds ( Figure 5). On the other hand, several investigators have reported a spherical, globular or disk like conformation for technical lignin or synthetic DHP [131][132][133][134][135][136]140]. Deconvolution fluorescence spectroscopy of DHPs suggested a multi-layered structure for lignin [141].…”

Section: Lignin Conformationmentioning

confidence: 99%

“…Using microscopy, Micic and colleagues published a series of papers [131][132][133][134][135][136] describing the supramolecular self-assembly of lignin in model systems of in vitro DHPs and photopolymerization of coniferyl alcohol. They envisioned lignin at the nanoscale as being globular with elastic and viscoelastic properties due to intermolecular π-π interactions, hydrogen bonding and van der Waals forces amongst the macromolecular globules resulting in semi-ordered superstructures.…”

Section: Supramolecular Ligninmentioning

confidence: 99%

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Supramolecular Self-Assembled Chaos: Polyphenolic Lignin’s Barrier to Cost-Effective Lignocellulosic Biofuels

et al. 2010

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Phenylpropanoid metabolism yields a mixture of monolignols that undergo chaotic, non-enzymatic reactions such as free radical polymerization and spontaneous selfassembly in order to form the polyphenolic lignin which is a barrier to cost-effective lignocellulosic biofuels. Post-synthesis lignin integration into the plant cell wall is unclear, including how the hydrophobic lignin incorporates into the wall in an initially hydrophilic milieu. Self-assembly, self-organization and aggregation give rise to a complex, 3D network of lignin that displays randomly branched topology and fractal properties. Attempts at isolating lignin, analogous to archaeology, are instantly destructive and nonrepresentative of in planta. Lack of plant ligninases or enzymes that hydrolyze specific bonds in lignin-carbohydrate complexes (LCCs) also frustrate a better grasp of lignin. Supramolecular self-assembly, nano-mechanical properties of lignin-lignin, ligninpolysaccharide interactions and association-dissociation kinetics affect biomass deconstruction and thereby cost-effective biofuels production. OPEN ACCESSMolecules 2010, 15 8642

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Section: Lignin Conformationmentioning

confidence: 99%

Section: Supramolecular Ligninmentioning

confidence: 99%

Supramolecular Self-Assembled Chaos: Polyphenolic Lignin’s Barrier to Cost-Effective Lignocellulosic Biofuels

et al. 2010

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“…Different types of lignin have been described depending on the means of isolation [20][21][22][23][24]. From the chemical point of view, the parent lignin is an amorphous, polyphenolic material arising from an enzyme-mediated dehydrogenative polymerisation of three phenylpropanoid monomers: coumaryl, coniferyl and sinapyl alcohols [25][26][27][28]. The copolymer, thus, formed consists of substituted C 9 units (6 aromatic and 3 propene carbons) interconnected by C-O (mostly etheric) or C-C bonds [29].…”

Section: Introductionmentioning

confidence: 99%

Kraft lignin and silica as precursors of advanced composite materials and electroactive blends

2013

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In this study, advanced multifunctional silica/ lignin composite materials have been prepared. The main focus of this study includes the chemical modification of Kraft lignin, and its interaction with silica matrix, thereby providing the possibility of applying the obtained systems in a number of areas, including electrochemistry. Analysis of dispersive-morphological properties revealed that the samples containing 10-20 parts by weight of lignin had the best parameters. The elemental analysis of the final composites, thus, obtained indicated an increase in the contents of carbon, hydrogen and sulphur with increasing quantity of lignin used. Spectrophotometric evaluation of the products obtained, proves the successful synthesis of silica/ lignin composites which is manifested by the presence of characteristic bands of appropriate functional groups. The increasing intensity of these bands with increasing content of lignin in the silica matrix conforms entirely with the expectations. Thus, obtained composite powders were blended with multiwalled carbon nanotubes at the mass ratio of 1:2 with the aid of ultrasound. The blends were cast-deposited on glassy carbon electrode and the electrochemical activity was assessed by cyclic voltammetry. It revealed the presence of a redox system assigned to ligninderived quinone/hydroquinone couple.

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“…At the fracture surface, the spheres look similar and the NC phase can be identified as shown in Figure 9.2b. Fractured spheres indicate Recent work on lignin structure, coniferyl alcohol polymerization and organization on solid substrates, and coniferyl alcohol polymerization in the presence of cellulose and soluble hemicelluloses shows several common features that may be generic to lignification [33,37,[40][41][42][56][57][58][59][60][61]. It has been demonstrated that actual lignin fragments aggregate into particles with a cross-sectional area of 0.048 μm 2 , which would give aggregates of about 0.22 μm in diameter [57].…”

Section: Nanocomposite Morphologymentioning

confidence: 99%

Composites of Nanocellulose and Lignin‐like Polymers

Barone

2014

Cellulose Based Composites

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IntroductionPolymeric nanocomposites are defined as polymer matrices filled with a nanometersized filler. These materials are usually combinations of rigid nanoclay fillers in much less rigid polyolefins [1]. There has been more recent interest in using biobased reinforcements such as nanocrystalline cellulose. Nanocrystalline cellulose can assume several forms depending on the source and processing method. Most is produced through acid hydrolysis. Native cellulosic sources produce round nanocrystals that have diameters up to ∼10 nm when derived from wood and cotton and >10 nm when derived from algae or tunicate [2][3][4][5][6][7]. Tunicate nanocellulose (NC) can be up to micrometers in length, which is an order of magnitude longer than those obtained from other sources [8]. Bacterial cellulose is as long as that derived from tunicate but has a rectangular cross section of 10 nm thickness and 50 nm width [4]. A combination of shear and enzymatic processing produces nanocrystals with a bimodal distribution of D = 5 and 15 nm [6]. The modulus of cellulose nanocrystals is greater than 100 GPa and combined with the high aspect ratio makes the reinforcement potential very high [9][10][11]. Polymeric matrices incorporating NC as the reinforcing phase include synthetic and biobased thermoplastics [12][13][14][15][16][17][18]. Results are mixed with positive reinforcement occurring only for polymeric matrices of low modulus. Thermosetting matrices have also been used, most notably phenol-formaldehyde, the most common wood adhesive [19][20][21][22][23][24]. NC seems to be the best reinforcement for itself with cellulose-based polymer matrices or amorphous cellulose able to be positively reinforced [25][26][27][28][29].The use of NC in nanocomposites is leveraging the same technology that plants use to attain strength and rigidity: ordered cellulose in a more disordered polymeric matrix. The plant cell wall is made by in situ polymerization of phenolic monomers (lignin) into a web of polysaccharides (cellulose and hemicellulose), a process that is catalyzed by polyphenoloxidases (laccases) or peroxidases [30]. Typical lignin monomers are coniferyl alcohol, coumaryl alcohol, and sinapyl alcohol. In this highly structured fiber composite material, semicrystalline cellulose fibrils provide mechanical strength, while the relatively hydrophobic lignin acts

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Study of the lignin model compound supramolecular structure by combination of near-field scanning optical microscopy and atomic force microscopy

Cited by 38 publications

References 41 publications

Supramolecular Self-Assembled Chaos: Polyphenolic Lignin’s Barrier to Cost-Effective Lignocellulosic Biofuels

Supramolecular Self-Assembled Chaos: Polyphenolic Lignin’s Barrier to Cost-Effective Lignocellulosic Biofuels

Kraft lignin and silica as precursors of advanced composite materials and electroactive blends

Composites of Nanocellulose and Lignin‐like Polymers

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