•Up-to-date usage of cellulose and its derivatives for 3D printing.•Summary of different functions of cellulose and its derivatives in 3D printing.•The shear-thinning feature imparts cellulose/its ...derivatives with good printability.•Water-soluble/water-dispersible cellulose derivatives preferred for 3D printing.•Various examples of cellulose/its derivatives in 3D printing discussed.
Three-dimensional (3D) printing is classified as a revolutionary, disruptive manufacturing technology. Cellulose (the most abundant natural polymer) and its many derivatives have been widely studied for many applications. The combination of 3D printing with cellulose-based feedstocks is therefore of critical interest. This review highlights many studies on 3D printing applications of plant-derived cellulose and its derivatives. Potential materials include cellulose ethers/esters, microcrystalline cellulose, nanocellulosic materials, and other products. It focuses on their roles and functions in 3D printing processes and the performance of the resultant printed objects. The outlook for future work is also provided, to underscore critical issues and opportunities.
Fabrication of aqueous particulate dispersions of biodegradable cellulose esters (CEs) as efficient carriers of agrochemical active‐ingredients (AIs) for foliar applications, is reported. The use of ...different ester substituent groups on CE permits modulation of particle morphology and size, from irregular shapes (<350 nm) to spheres (≈1.1 µm diameter), while maintaining stability as supported by minimal change in zeta potential and particle size over one year. Rainfastness is tested by simulating >50 mm h−1 rainfall on coated banana and tomato leaves and silicon. Surface coverage loss as low as 9%, based on the nature of leaf and formulation, confirms the rainfastness of the formulations. Variation in the release kinetics of a model AI fluopyram from different CEs can be attributed to the particle morphology and the nature of binding between fluopyram and various CEs. Thermodynamic analysis demonstrates spontaneous binding between fluopyram and multiple sites of CEs, justifying its two‐step release from CE particles. System functionalities are corroborated via in‐vitro fungal inhibition assays demonstrating a 100% inhibition of the fungal growth. This “lab‐to‐leaf” approach of materials development involving fundamental insights and functional performance reveals CE dispersions are promising green agricultural formulations with the potential to impact a myriad of crops around the globe.
Sustained release formulations with strong adherence and efficient rainfastness on various types of plants are developed from aqueous dispersion of biodegradable cellulose esters particles. These dispersions loaded with active ingredients (AI) can serve as smart formulations, which can be tailored based on the requirements of the crop and nature of the AI.
Cellulose Ester Dispersion
To minimize the deleterious impacts of agrochemicals and polymer carriers, in article number 2108046, Charles H. Opperman, Saad A. Khan, and co‐workers design aqueous ...dispersions of biodegradable polymers with tunable morphology. These green formulations show controlled release, fast spread, and impressive resistance to washing off from rain when used in foliar applications.
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•Mixed cellulose ester (MCE) separator is applied to tailor the zinc deposition in AZBs based on physical and chemical effect.•The physical shunting effect by the uniform and dense ...pore structure can control and homogenize the ion movement.•The mechanism of physical pore effect is illuminated by comparing MCE membranes with similar component but different pore size.•The chemical guiding effect for ion diffusion is realized by the coordination between polar functional groups in MCE and Zn2+.
Aqueous zinc-ion batteries (AZBs) with high energy density, low cost and environmental characteristics, have become the promising device for energy storage. However, uncontrolled zinc dendrite growth remains an impediment to the popularization of AZBs. The unrestricted two-dimensional (2D) ions diffusion is the main cause of the above defect. In this work, mixed cellulose ester (MCE) membrane is proposed as the separator. A dense homogeneous pore structure can achieve a physical shunting effect on ion diffusion, which can control and homogenize the ion motion. Further, the mechanism of this physical pore effect is confirmed by comparing the behavior of Zn deposition in MCE systems with different pore sizes but the same composition. As conjectured, a membrane with a smaller pore size is more favorable. In addition, the MCE contains many polar oxygen-containing functional groups that can facilitate and modulate ion diffusion through coordination. This chemical ion guiding effect, together with the above physical pore effect, gives the separator the ability to suppress dendrite formation. Zn/Zn symmetric cells with this membrane exhibit ultralong cycle life exceeding 1250 h at 0.5 mA cm−2 and 1000 h at 5 mA cm−2. And the Zn//MnO2 battery presents excellent cycle stability for more than 500 cycles with a capacity retention of 90.67%. This work proposes MCE separators and reveals their coordinated regulation of physical and chemical effects on metal-based anodes. This will shed light on the development of high-performance separators and AZBs.
•The cellulose ester–graft–polylactide copolymers was synthesized using an ionic liquid one-pot system.•The structures and compositions of the copolymers were controlled by varying the feed content ...of reagents and the copolymers exhibited DSAcyl values of 0.7–2.7 and MSPLA values of 3.2–14.2.•The effect of graft-chain composition on thermal stabilities, thermoplasticities, mechanical properties and biodegradability was investigated.
With the aim of developing polymers having controlled thermoplasticities and biodegradabilities, a series of cellulose ester–graft–polylactide copolymers was synthesized using a homogeneous one-pot system in which the reaction medium was the ionic liquid 1-ethyl-3-methylimidazolium diethylphosphate (EmimDEP). The structures and compositions of the copolymers were controlled by varying the feed ratio of the carboxylic anhydride (acetic (C2), propionic (C3), or hexanoic (C6)) and L-lactide. In terms of side-chain substitution, the copolymers exhibited DSAcyl values of 0.7–2.7 and MSPLA values of 3.2–14.2. With increasing DSAcyl, the copolymers presented enhanced thermal stability and thermoplasticity due to the intermolecular interactions between the acyl groups and polylactide side-chains. The effect of graft-chain composition on mechanical properties and biodegradability was investigated using homogeneous cast films prepared with the copolymers. The mechanical properties were found to be affected by the carbon number of the acyl group (C2–C6), with higher carbon numbers imparting better plasticization. To investigate biodegradability, a two-step enzymatic degradation was performed using proteinase K and then cellulase. The copolymers with DSAcyl values below 1.3 exhibited enzymatic biodegradability with weight losses in the range 15.2%–34.6% (cf. 58.4% for polylactide).
•A universal strategy is proposed to improve the environmental resistance of air filters.•An ultrathin alumina layer is conformally deposited on a porous membrane via ALD.•An alumina shell ...effectively protects a polymer core from various external stimuli.•The resulting composite membrane shows excellent PM filtration efficiency (∼99%).•PM filtration efficiency does not deteriorate even after water spraying.
In this study, a composite membrane was developed by conformally coating an ultrathin Al2O3 layer through low-temperature (90 °C) atomic layer deposition (ALD) on a hydrophilic mixed cellulose ester (MCE) membrane with a 3D networked microporous structure. The thickness of the deposited Al2O3 layer, without clogging the pores of the membrane, was precisely controlled by varying the number of ALD cycles from 100 to 300. The ultrathin (∼33 nm) Al2O3 layer greatly enhanced the resistance to various environmental stimuli and contributed to the improved removal efficiency of airborne particulate matter (PM), owing to the reduced pore size. The resulting composite membrane installed on an insect screen exhibited excellent removal efficiency (>99%) for PM of various sizes (PM1.0, PM2.5, and PM10) at a controlled flow rate of 1 L/min. In particular, unlike polypropylene-based commercial PM filters that strongly rely on electrostatic adsorption for PM filtration, the reduction in the PM removal efficiency caused by water or ethanol was negligible in the developed composite membrane, enabling long-term use even in extreme environments.
The development of economically and ecologically viable strategies for superhydrophobization offers a vast variety of interesting applications in self-cleaning surfaces. Examples include packaging ...materials, textiles, outdoor clothing, and microfluidic devices. In this work, we produced superhydrophobic paper by spin-coating a dispersion of nanostructured fluorinated cellulose esters. Modification of cellulose nanocrystals was accomplished using 2H,2H,3H,3H-perfluorononanoyl chloride and 2H,2H,3H,3H-perfluoroundecanoyl chloride, which are well-known for their ability to reduce surface energy. A stable dispersion of nanospherical fluorinated cellulose ester was obtained by using the nanoprecipitation technique. The hydrophobized fluorinated cellulose esters were characterized by both solid- and liquid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and contact angle measurements. Further, we investigated the size, shape, and structure morphology of nanostructured fluorinated cellulose esters by dynamic light scattering, scanning electron microscopy, and X-ray diffraction measurements.
Wood-derived biopolymers have attracted great attention over the past few decades due to their abundant and versatile properties. The well-separated three main components, i.e., cellulose, ...hemicelluloses, and lignin, are considered significant candidates for replacing and improving on oil-based chemicals and materials. The production of nanocellulose from wood pulp opens an opportunity for novel material development and applications in nanotechnology. Currently, increased research efforts are focused on developing 3D printing techniques for wood-derived biopolymers for use in emerging application areas, including as biomaterials for various biomedical applications and as novel composite materials for electronics and energy devices. This Review highlights recent work on emerging applications of wood-derived biopolymers and their advanced composites with a specific focus on customized pharmaceutical products and advanced functional biomedical devices prepared via three-dimensional printing. Specifically, various biofabrication strategies in which woody biopolymers are used to fabricate customized drug delivery devices, cartilage implants, tissue engineering scaffolds and items for other biomedical applications are discussed.
Synopsis. Valorization of Eucalyptus bark for combined use of extracts, fiber bundles, and hemicellulose-rich hydrolysates.
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•Fiber bundles from eucalyptus bark can be separated under ...low alkaline conditions.•High compatibility between fiber bundles with cellulose acetate butyrate.•Valuable hot water extracts can be integrated together with fiber bundle separation.•Utilizing aligned fiber bundles as the reinforcement for composite is promising.•Valorization of Eucalyptus bark for co-production of extracts and fiber bundles.
High surface lignin content (i.e. 34.6 %) sclerenchyma fiber bundles were successfully isolated with a yield of 71 % by a mild alkali (NaOH dosage of 5 wt%) extraction of eucalyptus (Eucalyptus globulus) bark under 100 °C for 60 min.. The mechanical properties of the composites prepared by hot pressing of cellulose acetate butyrate (CAB) sheets with the fiber bundles were evaluated. The fiber bundles exhibited good compatibility with CAB due to their hydrophobic fiber surfaces. The mechanical properties of the fiber bundle/ cellulose acetate butyrate composites revealed the maximum at a weight ratio of 25:75, which demonstrates the promise of utilizing these isotropic aligned fiber bundles as the reinforcement to the cellulose acetate butyrate without the addition of plasticizers for composite uses.
3D bioprinting is a versatile technique that allows the fabrication of living tissue analogs through the layer-by-layer deposition of cell-laden biomaterials, viz. bioinks. In this work, composite ...alginate hydrogel-based bioinks reinforced with curcumin-loaded particles of cellulose esters (CEpCUR) and laden with human keratinocytes (HaCaT) are developed. The addition of the CEpCUR particles, with sizes of 740 ± 147 nm, improves the rheological properties of the inks, increasing their shear stress and viscosity, while preserving the recovery rate and the mechanical and viscoelastic properties of the resulting fully cross-linked hydrogels. Moreover, the presence of these particles reduces the degradation rate of the hydrogels from 26.3 ± 0.8% (ALG) to 18.7 ± 1.3% (ALG:CEpCUR_10%) after 3 days in the culture medium. The 3D structures printed with the ALG:CEpCUR inks reveal increased printing definition and the ability to release curcumin (with nearly 70% of cumulative release after 24 h in PBS). After being laden with HaCaT cells (1.2 × 106 cells mL–1), the ALG:CEpCUR bioinks can be successfully 3D bioprinted, and the obtained living constructs show good dimensional stability and high cell viabilities at 7 days post-bioprinting (nearly 90%), confirming their great potential for application in fields like wound healing.
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