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The substitution of synthetic raw materials with renewable feedstock is fueling a lot of interest to drive new scientific and technical advancements that underpin this strategy. In this context and looking at the broad prospect of chitosan, herein, we proposed a facile, economical, and novel strategy to process high-yield (44% ± 3) chitosan from waste crab shells and apply the processed chitosan to fabricate a durable, multifunctional, ecofriendly superhydrophobic coating. The coating was developed by binding the amines of chitosan and a long-chain polymer, octadecylamine using a cross-linking agent (glutaraldehyde). Applying the coating onto intrinsically hydrophilic polyester fabric and typical surgical-grade cotton yielded superhydrophobic materials with water contact angles of 158.6 and 161.4°(± 3), respectively. A preliminary study revealed that the coating could endure multiple cycles of laundry (60×), sandpaper abrasion (55×), and tape peel test (80×) with little diminution in the superhydrophobic property. Interestingly, any decrease in the superhydrophobicity could be restored after ironing the fabrics for 2 min, indicating that the effect was reversible. Furthermore, the coating could transform an ordinary hydrophilic polyurethane sponge into an excellent superhydrophobic− superoleophilic absorbent, which can rapidly absorb and separate a variety of organic solvents and oils from oil/water mixtures.

Micro-fluidized bed has aroused much attention due to its low-cost, intensified-process and fast-screening properties. In this paper, a micro-fluidized bed (15 × 15 mm in cross-section) was designed and fabricated with the use of the stereolithography printing technique, for the investigation of bubbles’ hydrodynamics and comparison of the solids (3D-printed particles VS fungal pellets) fluidization characteristics. In a liquid–gas system, bubble flow regime started from mono-dispersed homogeneous regime, followed by poly-dispersed homogeneous regime, transition bubble regime and heterogeneous bubble regime with increasing gas flowrates from 3.7 mL/min to 32.7 mL/min. The impacts from operating parameters such as gas flowrate, superficial liquid velocity and gas sparger size on bubble size, velocity and volume fraction have been summarized. In liquid–solid fluidization, different solid fluidization regimes for both particles bed and pellets bed were identified. From the bed expansion results, much higher Umf of 7.8 mm/s from pellets fluidization was observed compared that of 2.3 mm/s in particles fluidization, because the hyphal structures of fungal pellets increased surface friction but also tended to agglomerate. The similar R–Z exponent n (5.7 and 5.5 for pellets and particles, respectively) between pellets and particles was explained by the same solid diameter, but much higher Ut of 436 µm/s in particles bed than that of 196 µm/s in pellets bed is a consequence of the higher density of solid particles. This paper gives insights on the development of MFB and its potential in solid processing.

Prolonged exposure of fiber reinforced composite structures to high moisture and temperature in outdoor environment could lead to the degradation of mechanical properties of the materials. To provides reliable prediction of the delamination behavior as the moisture progressively ingresses into the composites, we proposed a Bilinear-Exponential Traction-Separation (BETS) lawwhich can account for the fiber bridging mechanism-for investigating the mode I delamination of unidirectional carbon fiber reinforced epoxy composite laminates in wet states. Finite element analysis (FEA) of the delamination model was conducted to evaluate the effects of moisture content on the global force-displacement curves. A cohesive zone model (CZM) was used to describe the delamination behavior at the interface. With regard to the forcedisplacement curves, the BETS law agrees well with results from experimental study (using the double cantilever beam testing on the wet specimens) at both the elastic and failure regions. The delamination model governed by the BETS law also showed good agreement with the crack length versus the crosshead displacement. The FE model that considered the inputs from the BETS law yielded prediction about the evolution of the damage parameter and crack growth profile. In particular, the predicted crack extension increases linearly with increasing crosshead displacement. The proposed BETS law has the advantage of not requiring crack growth monitoring during experiment, and only one fitting parameter was needed to describe the bridging law at different moisture content levels.Abbreviations: a o , initial crack length; BETS, bilinear-exponential traction-separation; BTS, bilinear traction-separation; COD, crack opening displacement; COH3D8, cohesive elements; CT, compact tension; CZL, cohesive zone length; CZM, cohesive zone model; d, crosshead displacement; D, damage parameter; da, crack extension (or incremental crack length); da ss , crack extension when steady-state fracture toughness is attained; DCB, double cantilever beam; E 11 , longitudinal modulus of the composite; E 22 , transverse modulus of the composite; E m , young's modulus of the epoxy resin; FML, fiber-metal laminates; G, fracture energy; G Ib , fracture energy due to fiber bridging effect; G IC , fracture toughness; G ss , steady-state fracture toughness; h ce , thickness of the cohesive element; K nn , mode I penalty stiffness; m, fracture toughness ratio; M, moisture content levels; n, strength ratio; SC8R, continuum shell elements; t b,n , bridging initiation traction; t n , normal traction; TTS, trilinear Traction-Separation; t u,n , mode I interface strength; VCCT, virtual crack closure technique; V f , fiber volume fraction; Y T , transverse tensile strength; α, cohesive zone model parameter; γ, fitting parameter in the damage parameter equation; δ b,n , bridging initiation separation; δ f,n , separation at ultimate failure; δ n -δ o,n , relative separation between normal and at damage initiation; δ n , normal separation; δ o,n , separatio...