Lightweight, Anisotropic, Compressible, and Thermally-Insulating Wood Aerogels with Aligned Cellulose Fibers

Sun, Hao; Bi, Hongjie; Lin, Xin; Cai, Liping; Xu, Min

doi:10.3390/polym12010165

Cited by 37 publications

(15 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The density of an aerogel can be as low as 0.004–0.5 g/cm 3 with a high porosity of up to 99.8% and a large specific surface area of 100–1600 m 2 /g [ 11 ]. Due to these properties, the aerogels have been applied as adsorbents of CO 2 [ 12 , 13 , 14 , 15 , 16 ], dyes, and heavy metals [ 2 , 3 , 11 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], as tissue engineering and blood system scaffolds in the biomedical field [ 3 , 22 , 23 , 24 , 25 , 26 , 27 ], and as materials for thermal insulation [ 4 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] and food packaging [ 37 , 38 , 39 , 40 , 41 ]. These versatile materials also exhibit high optical transparencies, low thermal conductivities (down to 12 mW/mK) and low sound speeds [ 42 , 43 ].…”

Section: Introductionmentioning

confidence: 99%

“…Natural polysaccharides contain crystalline and amorphous regions that are highly susceptible to hydrolysis. Various polysaccharides can be used to produce aerogels, including cellulose [ 24 ], starch [ 45 ], alginate [ 46 ], pectin [ 47 ], lignin [ 29 ], collagen [ 48 ], and chitosan [ 44 ]; however, cellulose and chitosan/chitin are the most commonly used and have therefore attracted current research interest. This is reflected in the plot of four types of polysaccharide gel reported in the literature against the year of publication in Figure 2 , where cellulose is seen to be the most reported since 2016.…”

Section: Introductionmentioning

confidence: 99%

“…Long, Weng and Wang (2018) classified cellulose aerogel into three categories, namely: natural cellulose, regenerated cellulose, and cellulose derivative aerogels [ 50 ]. Aerogels produced from plant cellulose require the extraction of impurities such as lignin, wax, pectin, and hemicellulose, a process that is also known as delignification [ 29 ]. The isolation of a nanocrystal from cellulose can be performed using chemical or enzymatic hydrolysis with or without mechanical treatment [ 41 ].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Recent Progress in Polysaccharide Aerogels: Their Synthesis, Application, and Future Outlook

Muhammad¹,

Lee²,

Shin³

et al. 2021

Polymers

View full text Add to dashboard Cite

Porous polysaccharides have recently attracted attention due to their porosity, abundance, and excellent properties such as sustainability and biocompatibility, thereby resulting in their numerous applications. Recent years have seen a rise in the number of studies on the utilization of polysaccharides such as cellulose, chitosan, chitin, and starch as aerogels due to their unique performance for the fabrication of porous structures. The present review explores recent progress in porous polysaccharides, particularly cellulose and chitosan, including their synthesis, application, and future outlook. Since the synthetic process is an important aspect of aerogel formation, particularly during the drying step, the process is reviewed in some detail, and a comparison is drawn between the supercritical CO2 and freeze drying processes in order to understand the aerogel formation of porous polysaccharides. Finally, the current applications of polysaccharide aerogels in drug delivery, wastewater, wound dressing, and air filtration are explored, and the limitations and outlook of the porous aerogels are discussed with respect to their future commercialization.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Recent Progress in Polysaccharide Aerogels: Their Synthesis, Application, and Future Outlook

Muhammad¹,

Lee²,

Shin³

et al. 2021

Polymers

View full text Add to dashboard Cite

show abstract

“…The excellent adsorption performance of biochar is governed by many characteristics of its own, such as a high SSA and a highly developed internal void structure. , N 2 adsorption–desorption experiments were carried out for CW, activated CW (ACW), and ACDW samples to determine the SSA and the pore structures. As shown in Figure g, both the CW and CDW display a reversible type II isotherm according to the International Union of Pure and Applied Chemistry (IUPAC) classification, which is indicative of the typical mesoporous material.…”

Section: Results and Discussionmentioning

confidence: 99%

Versatile Strategy for the Preparation of Woody Biochar with Oxygen-Rich Groups and Enhanced Porosity for Highly Efficient Cr(VI) Removal

et al. 2021

View full text Add to dashboard Cite

Biochar is widely used to remove hexavalent chromium [Cr(VI)] from wastewater through adsorption, which is recognized as a facile, cost-efficient, and high-selectivity approach. In this study, a versatile strategy that combines delignification with subsequent carbonization and KOH activation is proposed to prepare a novel woody biochar from waste poplar sawdust. By virtue of the unique multilayered and honeycomb porous structure induced by delignification and activation processes, the resultant activated carbonized delignified wood (ACDW) exhibits a high specific surface area of 970.52 m 2 g –1 with increasing meso- and micropores and abundant oxygen-containing functional groups. As a benign adsorbent for the uptake of Cr(VI) in wastewater, ACDW delivers a remarkable adsorption capacity of 294.86 mg g –1 in maximum, which is significantly superior to that of unmodified counterparts and other reported biochars. Besides, the adsorption behaviors fit better with the Langmuir isotherm, the pseudo-second-order kinetic model, and the adsorption diffusion model in batch experiments. Based on the results, we put forward the conceivable adsorption mechanism that the synergistic contributions of the capillary force, electrostatic attraction, chemical complexation, and reduction action facilitate the Cr(VI) capture by ACDW.

show abstract

“…Fabrication of Wood Scaffolds: The wood scaffolds were prepared by chemical extraction process following the previous study with slight modification. [26] Specifically, the wood specimens were initially ovendried at 103 °C for 12 h prior to experiments. A delignification solution containing 2 wt% NaClO 2 was prepared and buffered with acetic acid to pH 4.6.…”

Section: Methodsmentioning

confidence: 99%

Flexible, Strong, Anisotropic Wood‐Derived Conductive Circuit

Sun

et al. 2021

Advanced Sustainable Systems

Self Cite

View full text Add to dashboard Cite

its flexibility, low cost, and simple process technology. [2] However, the continuous generation and accumulation of plastic waste has severely damaged the environment and human health.Cellulose is the most abundant natural polymer, extracted from bioresources and degraded under natural conditions. [3] Furthermore, cellulose exhibits outstanding mechanical properties, low thermal expansion coefficient, and chemically accessible for the modification. [4] Given these properties, the cellulose film holds great potential to construct substrate materials for flexible electronics. [5] Traditionally, the cellulose film is produced by a complex process, which mainly includes three steps: 1) removing lignin and hemicellulose from wood flour or other biomass powder; 2) releasing cellulose nanofibrils and cellulose nanocrystal through the mechanical nanofibrillation and chemical treatment such as high-pressure homogenizers, high-intensity ultrasonicator, [6] grinders, [7] acid hydrolysis, [8] and TEMPO-mediated oxidation; [9] 3) reconstructing cellulose film by different manufacturing approaches. [10] This bottom-up method is low efficient and high energy consumption, and simultaneously requires to use specific equipment and complicated process, which is an obstacle to large-scale application.Generally, the cellulose-based conductive composites composed of cellulose substrate and conductive filler are fabricated by blending, which leads to a randomly oriented structure. Moreover, the cellulose-based film exhibits poor electrical conductivity at a low content of conductive fillers. [11] To improve its electrical conductivity, the high volume of the conductive fillers is mixed into the cellulose substrate, which causes high cost and filler aggregation, even destroys the structure of composites, and then affects the mechanical strength. By designing an anisotropic and ordered structure, the high conductivity of composites with a low content of conductive fillers can be achieved. It is worth noting that some technology has been used to design, synthesis, and construct anisotropic structure such as ice-template, [12] mechanical stretch, [13] and magnetic field method. [14] Despite the tremendous efforts have been devoted, challenges still remain in achieving the scalable application, simple manufacturing process, and low energy consumption.Natural wood consists of a large amount of cellulose. The highly aligned microchannels of trees transport water and Flexible electronics have attracted tremendous attention because of the potential applications in flexible sensors and wearable electronics. Herein, a wood-derived conductive circuit is prepared through a simple top-down wood nanotechnology. Wood scaffolds with layered structure and aligned micro-nano channels are used as the flexible substrate and multi-walled carbon nanotubes (MWCNTs) are used as the conductive materials. Driven by the hydroxyl groups-induced hygroscopicity of wood scaffold, the MWCNTs are uniformly embedded into the wood scaffold. The conductive circuit exh...

show abstract

Lightweight, Anisotropic, Compressible, and Thermally-Insulating Wood Aerogels with Aligned Cellulose Fibers

Cited by 37 publications

References 45 publications

Recent Progress in Polysaccharide Aerogels: Their Synthesis, Application, and Future Outlook

Recent Progress in Polysaccharide Aerogels: Their Synthesis, Application, and Future Outlook

Versatile Strategy for the Preparation of Woody Biochar with Oxygen-Rich Groups and Enhanced Porosity for Highly Efficient Cr(VI) Removal

Flexible, Strong, Anisotropic Wood‐Derived Conductive Circuit

Contact Info

Product

Resources

About