Chitin Nanofibrils to Stabilize Long-Life Pickering Foams and Their Application for Lightweight Porous Materials

Abstract

The demand of sustainable development is challenging researchers to convert renewable resourced biomass into functional materials via environmentally friendly and sustainable pathways. This work introduces a long-life Pickering foam stabilized by chitin nanofibers (CNFs) as colloidal rod-like particles, and a facile method for fabricating lightweight porous solid foams that recycles biomass materials derived from seafood waste. These foams were formed by combining nonionic surfactant Tween 20 (T20) and CNFs, with the CNFs being irreversibly adsorbed at the air–water interface to provide Pickering stabilization. At a concentration of 7.5 mg/mL, the foams could be stable for over 1 week without any apparent drainage. The rheological data indicated the formation of gel networks by self-aggregated CNFs at the air–water interface, which provided long-term stabilization by preventing foam coalescence and disproportionation. This long-term stability of CNF-T20 wet foam has permitted the fabrication of solid porous matrix by removal of the water through simple air-drying. The air-dried chitin foams were ultralight weight porous materials with porosity of 99.4% and a density of 8.84 kg/m3. In addition, they exhibited significantly improved mechanical performance (Young’s modulus of ∼290.2 kPa) compared to porous chitin materials of comparable densities prepared by a traditional freeze-drying method. Therefore, this research has provided a convenient pathway for scalable processing of macroporous material from renewable biomass for potential applications in packaging, pollutant treatment, catalysis, tissue engineering and other related fields.

Self-Assembled Networks of Short and Long Chitin Nanoparticles for Oil/Water Interfacial Superstabilization

“…33 Therefore, NCh can be considered as a better chitin-based Pickering stabilizer compared to the commonly reported ChNC. 34,35 One recent example shows that NCh could stabilize Pickering emulsion but TEMPO-mediated zwitterionical modification of NCh was required, undermining its nature as green stabilizer. 36…”

Chitin nanocrystals as Pickering stabilizer for O/W emulsions: Effect of the oil chemical structure on the emulsion properties

“…The first work on the possibility of using ChNCs in emulsions was reported by Tzoumaki et al [18]who produced corn O/W emulsions stabilized by ChNCs and investigated the effect of ChNC concentration, ionic environment, pH and temperature on the emulsion properties. Since then, several articles have described the emulsification potential of nanochitins to produce nanocomposites [19,20], food emulsions [21], functional materials [22], foams [23], among others. Recently, stable O/W high-internal-phase (HIPE) Pickering emulsions stabilized solely by ChNCs were produced at a volume fraction amounting 88% [24,25].…”

Gel–Emulsion‐Templated Polymeric Aerogels for Water Treatment by Organic Liquid Removal and Solar Vapor Generation

“…Among materials used in water purification, porous materials have attracted extensive attention because of their low density, high porosity, and large specific surface area . A series of porous materials has been developed, and many have been proven to be efficient in water purification .…”

“…Among materials used in water purification, porousmaterials have attracted extensive attention because of their low density, high porosity,a nd large specific surfacea rea. [7][8][9] As eries of porousm aterials has been developed, and many have been provent ob ee fficient in water purification. [10] For example, some typical porousm aterials were able to remove heavy metal ions; [11] and favorable sorbents could be used repeatedly to remove crude oil from model seawater.…”