Nano‐enabled, bio‐based, functional materials are key for the transition to a sustainable society as they can be used, owing to both their performance and nontoxicity, to gradually replace existing ...nonrenewable engineering materials. Cellulose nanocrystals (CNCs), produced by acid hydrolysis of cellulosic biomass, have been shown to possess distinct self‐assembly, optical, and electromechanical properties, and are anticipated to play an important role in the fabrication of photonic, optoelectronic, and functional hybrid materials. To facilitate CNCs’ technological viability, a method suitable for industrial exploitation is developed to produce photonic films possessing long‐range chirality on conductive, rigid, or flexible, substrates within a few minutes. The approach is based on electrophoretic deposition (EPD)‐induced self‐assembly of CNCs, where photonic films of any size can be produced by controlling CNC surface properties and EPD parameters. CNC film coloration can be determined by the CNC aqueous suspension characteristics, while their reflected intensity can be tuned by changing the duration and number of electrodeposition cycles. EPD‐induced self‐assembly of CNCs is compatible with in situ reduction of gold precursors without the need to use additional reducing agents (some of which are considered toxic), thereby allowing the preparation of hybrid photonic films with tunable plasmonic response in a one‐pot process.
A fast and scalable electrophoretic‐deposition‐induced self‐assembly technique of photonic cellulose nanocrystal films, that can circumvent the long process evaporation‐induced self‐assembly (EISA), is developed. Iridescent films with tunable color can be achieved in a few minutes by simple adjustment of the suspension properties. Co‐assembly with plasmonic metal nanoparticles can be performed in one step with no addition of reducing agent.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The fabrication of self‐assembled cellulose nanocrystal (CNC) films of tunable photonic and mechanical properties using a facile, green approach is demonstrated. The combination of tunable ...flexibility and iridescence can dramatically expand CNC coating and film barrier capabilities for paints and coating applications, sustainable consumer packaging products, as well as effective templates for photonic and optoelectronic materials and structures.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Oil-in-water emulsions stabilized solely by cellulose filaments (CF), a biomaterial produced from renewable sources (wood pulp) by mechanical processing without chemical treatments.
Display omitted
...•Cellulose filaments (CF) stabilize medium and high internal phase oil-in-water Pickering emulsions.•CF fibrils form a fibrillar layer at the oil-water interface in Pickering emulsions.•The inhomogeneity of CF morphology plays a critical role in emulsion stabilization.•The fibrillation level and concentration of CF have strong effect on emulsion stability.•Lignin-containing CF has superior performance in emulsion stabilization at high pH.
Cellulose filaments (CFs) are produced from wood-pulp fibres through solely mechanical treatment. They are inhomogeneous materials comprising both relatively large fibre fragments and fine fibrils. CFs can stabilize oil-in-water medium- and high-internal phase Pickering emulsions, where the presence of fibre fragments plays a critical role in emulsion stabilization by preventing CF fibrils from forming highly entangled structures. The emulsion properties are shown to be influenced by both the refining energy and CF concentration. CFs are distinct from cellulose nanofibrils (CNF) or microfibrillated cellulose (MFC), which flocculate and collapse owing to the entanglement of the homogeneous fibrous mass. Typically, other additives – surfactants or cellulose nanocrystals – are necessary to stabilize such emulsions. Further, lignin-containing CFs, produced from unbleached pulps, are particularly beneficial for emulsion stabilization at higher pH when the functional groups on lignin molecules are ionized. Our findings present CFs as potentially inexpensive, sustainable, and efficient emulsifiers for a wide variety of systems, from food to personal care products or engineering materials.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A systematic examination of the structureproperty relations to create nanocomposite coatings
via
electrophoretic deposition (EPD) of a cathodic polymer for instance, polyacrylate reinforced with ...cellulose nanocrystals (CNCs) is discussed in this work. EPD, a scalable and green technique, has also been used in our approach to polymerize dopamine in the presence of CNCs and cathodic polymer to improve adhesion properties. This study investigated the interactions between CNCs, polydopamine (PDA) and the cathodic polyacrylic polymer to elucidate the dispersion state of the nanoparticles in the system by carefully examining
-potential, particle size, and electrophoretic mobility dependence in the colloidal suspension. We examined the morphology and structure of the electrodeposited nanocomposites using SEM and XPS, and the results indicate the formation of a compact, homogeneous structure. The incorporation of CNCs or PDA introduces different levels of roughness to the surface as revealed by AFM. Our results indicate improved adhesion, as determined by bond strength, using CNCs (>20%) or CNCPDA (>30%) relative to the cathodic polymer, as well as significant improvement in hardness. The technique and materials used show promise to develop industrial organic coatings with low emissions for applications in automotive coatings and other applications.
Cathodic electrophoretic deposition (EPD) of cellulose nanocrystals and suitable polymers with enhanced performance.
We have developed an essentially green, bottom-up approach for synthesising flexible, organic, semi-conducting nanocomposite films based on cellulose nanocrystals (CNCs) and polyaniline (PANI) ...through aqueous emulsion polymerization. Dodecylbenzene sulfonic acid (DBSA) was used as surfactant and dopant for the emulsion. CNCs and DBSA micelle concentrations, their structural organization and alignment with the monomer in the emulsion have a significant effect on the physical and mechanical properties of the resulting nanocomposite films with electrical conductivity reaching as high as 5.29 × 10 −1 S cm −1 which falls in the electrical conductivity range of germanium (2.24 × 10 −2 S cm −1 ) and silicon (0.43 × 10 −5 S cm −1 ) S. L. Kakani, Electronics Theory and Applications, New Age International, 23–24, 2005. The CNCs–PANI–DBSA nanocomposite films show a maximum tensile stress and strain values of 22 MPa and 0.89%, respectively and are significantly stronger and more flexible films than those obtained with, for instance, graphene/polyaniline composite paper or graphene paper, where it has been reported in the literature that the tensile strengths were 12.6 and 8.8 MPa, and maximum strains, 0.11 and 0.08%, respectively Wang et al. , ACS Nano , 2009, 3 , 1745.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
Our paper presents two approaches that are potentially industrially scalable to prepare polymer electrolytes for the development of next-generation rechargeable batteries involving new atoms like Na, ...Zn or Mg: (1) gel polymer electrolytes, GPE, and (2) solid polymer electrolytes, SPE. Cellulose nanocrystals (CNC) are used with different surface functions, surface charge and concentrations as a functional component in both systems. Systematic testing of their ionic conductivity as well as their dynamic mechanical behavior, which is critical for creating mechanically durable systems, has been performed. Higher ionic conductivity reaching up to 2.60 ± 0.57 mS/cm was obtained for cellulose based GPE, which is more than double the ionic conductivity tested for non-renewable Celgard® 2400 (1.15 ± 0.06 mS/cm). Whereas cellulose based SPE showed an ionic conductivity of up to 2.34 ± 0.28 × 10−6 S/cm, and in both systems, tailoring the surface charge on CNC surfaces significantly influenced the counterion mobility thereby improving the ionic conductivity.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Conducting poly(3,4-ethylenedioxythiophene) (PEDOT) was synthesized via an oxidative polymerization process in the presence of cellulose nanocrystals (CNCs). The polymerization kinetics and ...parameters affecting the physical and electrical properties of the PEDOT:CNC nanomaterials were systematically investigated. Our findings reveal that the unique nanostructure of PEDOT:CNC and the tunable surface functionality of CNCs play a major role in conductivity enhancement. The conductivity of PEDOT:CNC films reached up to 23.8 S cm–1 without post-treatment; this is ∼2 orders of magnitude higher than commercial PEDOT:PSS (ca. 0.26 S cm–1). PEDOT:CNC aqueous suspensions exhibit shear-thinning and gel-like behavior as opposed to PEDOT:PSS, which predominantly behaves as a viscous fluid. These findings highlight the potential utility of PEDOT:CNC nanomaterials in organic electronic applications, particularly as conductive inks for printed electronics.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
We have developed an essentially green, bottom-up approach for synthesising flexible, organic, semi-conducting nanocomposite films based on cellulose nanocrystals (CNCs) and polyaniline (PANI) ...through aqueous emulsion polymerization. Dodecylbenzene sulfonic acid (DBSA) was used as surfactant and dopant for the emulsion. CNCs and DBSA micelle concentrations, their structural organization and alignment with the monomer in the emulsion have a significant effect on the physical and mechanical properties of the resulting nanocomposite films with electrical conductivity reaching as high as 5.29 × 10
−1
S cm
−1
which falls in the electrical conductivity range of germanium (2.24 × 10
−2
S cm
−1
) and silicon (0.43 × 10
−5
S cm
−1
) S. L. Kakani, Electronics Theory and Applications, New Age International, 23-24, 2005. The CNCs-PANI-DBSA nanocomposite films show a maximum tensile stress and strain values of 22 MPa and 0.89%, respectively and are significantly stronger and more flexible films than those obtained with, for instance, graphene/polyaniline composite paper or graphene paper, where it has been reported in the literature that the tensile strengths were 12.6 and 8.8 MPa, and maximum strains, 0.11 and 0.08%, respectively Wang
et al.
,
ACS Nano
, 2009,
3
, 1745.
Flexible, organic electronics for sustainable technologies.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
PDF
