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Fully biodegradable packaging materials are demanded to resolve the issue of plastic pollution. However, the fresh food storage performance of biodegradable materials is generally much lower than that of plastics due to their high permeability, microbial friendliness, and limited stretchability and transparency. Here a biodegradable packaging material is reported with high fresh food storage performance based on an oil‐infused bacterial cellulose (OBC) porous film. The oil infusion significantly improved cellulose's food‐keeping performance by reducing its gas permeability, increasing its stretchability and transparency, and enabling the active release of green vapor‐phase preservative molecules, while maintaining its intrinsically high degradability. Strawberries stored in a container with the OBC lid at 23 °C after 5 days exhibited a moldy rate of 0%, in contrast to the 100% moldy rate of those stored by poly(ethylene). Enhanced storage performance is also obtained on tomatoes, pork, and shrimp. The OBC film is naturally degraded after being buried in wet soil at 30 °C for 9 days, identical to the degradation rate of bacterial cellulose. The liquid seal strategy broadly applies to different celluloses, providing a general option for developing cellulose‐based biodegradable packaging materials. [ABSTRACT FROM AUTHOR]

Abstract Fully biodegradable packaging materials are demanded to resolve the issue of plastic pollution. However, the fresh food storage performance of biodegradable materials is generally much lower than that of plastics due to their high permeability, microbial friendliness, and limited stretchability and transparency. Here a biodegradable packaging material is reported with high fresh food storage performance based on an oil‐infused bacterial cellulose (OBC) porous film. The oil infusion significantly improved cellulose's food‐keeping performance by reducing its gas permeability, increasing its stretchability and transparency, and enabling the active release of green vapor‐phase preservative molecules, while maintaining its intrinsically high degradability. Strawberries stored in a container with the OBC lid at 23 °C after 5 days exhibited a moldy rate of 0%, in contrast to the 100% moldy rate of those stored by poly(ethylene). Enhanced storage performance is also obtained on tomatoes, pork, and shrimp. The OBC film is naturally degraded after being buried in wet soil at 30 °C for 9 days, identical to the degradation rate of bacterial cellulose. The liquid seal strategy broadly applies to different celluloses, providing a general option for developing cellulose‐based biodegradable packaging materials.

[Display omitted] • A universal approach was proposed to introduce microporous metallic scaffolds in the LIS construction to prompt the potential of LIS for ice mitigation. • The new LIS construction offered a solution for the rapid oil depletion by restraining the deformation of the matrix material. • The multiphase icephobic layer structures have demonstrated good icephobicity and significantly improved durability. Hypothesis: Ice accretion on component surfaces often causes severe impacts or accidents. Liquid-infused surfaces (LIS) have drawn much attention as icephobic materials for ice mitigation in recent years due to their outstanding icephobicity. However, the durability of LIS constructions remains a big challenge, including mechanical vulnerability and rapid depletion of lubricants. The practical applications of LIS materials are significantly restrained, and the full potential of LIS for ice prevention has yet to be demonstrated. Experiments: A universal approach was proposed to introduce microporous metallic scaffolds in the LIS construction to increase the applicability and durability, and to prompt the potential of LIS for ice mitigation. Microporous Ni scaffolds were chosen to integrate with polydimethylsiloxane modified by silicone oil addition. Findings: The new LIS construction demonstrated significantly improved durability in icing/de-icing cyclic test, and it also offered a solution for the rapid oil depletion by restraining the deformation of the matrix material. Low ice adhesion strength could be maintained via a micro-crack initiation mechanism. The results indicated that the multi-phase LIS construction consisting of microporous Ni scaffolds effectively addressed the shackles of the icephobicity deterioration of LIS materials, confirming a new design strategy for the R&D of icephobic surfaces. [ABSTRACT FROM AUTHOR]

This study unleashes the potential of nanoporous connected networks as excellent oil reservoirs for reducing friction and wear in Al2O3-Al2O3 tribo-pairs. Alumina were fabricated via slip casting and sintering to generate wide-ranging densifications (70–99.5%) and slid in a reciprocating flat-on-flat configuration. Friction coefficients (FCs) lie between 0.025 and 0.37 which decreased with an increase in normal load (10–220 N), lubricant’s viscosity (19, 289 mPa·s) and sliding frequency (6, 12, 24 Hz). A central finding is that FCs of infused specimens are smaller than those of surface lubricated. Wear rates decreased from 10−5 to

Many polymer materials have found a wide variety of applications in biomedical industries due to their excellent mechanical properties. However, the infections associated with the biofilm formation represent serious problems resulting from the initial bacterial attachment on the polymeric surface. The development of novel slippery liquid-infused porous surfaces (SLIPSs) represents promising method for the biofilm formation prevention. These surfaces are characterized by specific microstructural roughness able to hold lubricants inside. The lubricants create a slippery layer for the repellence of various liquids, such as water and blood. In this study, effective antimicrobial modifications of polyethylene (PE) and polyurethane (PU), as commonly used medical polymers, were investigated. For this purpose, low-temperature plasma treatment was used initially for activation of the polymeric surface, thereby enhancing surface and adhesion properties. Subsequently, preparation of porous microstructures was achieved by electrospinning technique using polydimethylsiloxane (PDMS) in combination with polyamide (PA). Finally, natural black seed oil (BSO) infiltrated the produced fiber mats acting as a lubricating layer. The optimized fiber mats’ production was achieved using PDMS/PA mixture at ratio 1:1:20 (g/g/mL) using isopropyl alcohol as solvent. The surface properties of produced slippery surfaces were analyzed by various microscopic and optics techniques to obtain information about wettability, sliding behavior and surface morphology/topography. The modified PE and PU substrates demonstrated slippery behavior of an impinged water droplet at a small tilting angle. Moreover, the antimicrobial effects of the produced SLIPs using black seed oil were proven against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli).

[Display omitted] • Fomblin® Y25/6 oil is an excellent lubricant for self-mating nanoporous alumina. • 90% Al 2 O 3 relative density is the optimal in the range of 70–99.5% for achieving best tribological properties. • Friction coefficients decreased with increase in normal loads (10–220 N) and sliding frequencies (1–24 Hz). • Lowest friction coefficient of 0.025 was recorded for 95% dense self-mating lubricated Al 2 O 3. • Wear occurred by intergranular fracture in 70–90% dense Al 2 O 3 and transgranular fracture in 95–99.5% dense Al 2 O 3. This study unleashes the potential of nanoporous connected networks as excellent oil reservoirs for reducing friction and wear in Al 2 O 3 -Al 2 O 3 tribo-pairs. Alumina were fabricated via slip casting and sintering to generate wide-ranging densifications (70–99.5%) and slid in a reciprocating flat-on-flat configuration. Friction coefficients (FCs) lie between 0.025 and 0.37 which decreased with an increase in normal load (10–220 N), lubricant's viscosity (19, 289 mPa·s) and sliding frequency (6, 12, 24 Hz). A central finding is that FCs of infused specimens are smaller than those of surface lubricated. Wear rates decreased from 10−5 to <10−8 mm3·N−1·m−1 for an increase in Al 2 O 3 density. Wear occurred predominantly via intergranular and transgranular fracture modes as revealed by the electron microscopy studies. [ABSTRACT FROM AUTHOR]

HD lubricant is more effective than PDMS and PHMS to prepare a slippery liquid-infused porous surface (SLIPS) for anti-icing application. The formation of solid HD crystals under freezing condition makes the HD-infused surface physically smooth and chemically homogenous, decreasing the ice adhesion strength and the interface abrasion of HD. • SLIPS is easily fabricated by infusing lubricant into porous polymer matrix. • The solid nature of HD under freezing condition favors the robust icephobicity. • Affinity between matrix and lubricant is important to anti-icing robustness. • This work helps to select lubricant and matrix to design robust icephobic SLIPS. This work concentrated on the fabrication of effective slippery liquid-infused porous surfaces (SLIPSs) to robustly resist ice adhesion by using facile method and smart composition. Firstly, poly(methyl methacrylate) (PMMA), polyhedral oligomeric silsesquioxane end-functionalized PMMA (POSS- ef -PMMA) and polydimethylsiloxane-blocked PMMA (PDMS- b -PMMA) were synthesized. Secondly, micro-sized pores arranged in a three-layer honeycomb-like array at a thickness of ca. 10 μm were elicited on each surface of these three cast polymer films by breath-figure (BF) method. After a separate infiltration of polydimethylsiloxane (PDMS), poly (hydrogenmethylsiloxane) (PHMS) and hexadecane (HD) into the porous matrixes, typical SLIPSs were formed. PDMS-b-PMMA matrix with preferential lipophilicity towards PDMS endowed the obtained SLIPS with better icephobicity. However, HD-induced SLIPSs performed the lowest sliding angles at 6° for 3 μL of water droplet, the lowest ice adhesional strength ranging from 40.8–46.3 kPa and the most robust anti-icing properties of resisting more than 30 icing/de-icing cycles without changing the ice adhesional strength. Such effective anti-icing performance was ascribed to the better liquid nature of HD in contact with water and the solid nature of HD under freezing condition, which could decrease the interfacial friction and abrasion of HD against water or ice. [ABSTRACT FROM AUTHOR]

Many polymer materials have found a wide variety of applications in biomedical industries due to their excellent mechanical properties. However, the infections associated with the biofilm formation represent serious problems resulting from the initial bacterial attachment on the polymeric surface. The development of novel slippery liquid-infused porous surfaces (SLIPSs) represents promising method for the biofilm formation prevention. These surfaces are characterized by specific microstructural roughness able to hold lubricants inside. The lubricants create a slippery layer for the repellence of various liquids, such as water and blood. In this study, effective antimicrobial modifications of polyethylene (PE) and polyurethane (PU), as commonly used medical polymers, were investigated. For this purpose, low-temperature plasma treatment was used initially for activation of the polymeric surface, thereby enhancing surface and adhesion properties. Subsequently, preparation of porous microstructures was achieved by electrospinning technique using polydimethylsiloxane (PDMS) in combination with polyamide (PA). Finally, natural black seed oil (BSO) infiltrated the produced fiber mats acting as a lubricating layer. The optimized fiber mats' production was achieved using PDMS/PA mixture at ratio 1:1:20 (g/g/mL) using isopropyl alcohol as solvent. The surface properties of produced slippery surfaces were analyzed by various microscopic and optics techniques to obtain information about wettability, sliding behavior and surface morphology/topography. The modified PE and PU substrates demonstrated slippery behavior of an impinged water droplet at a small tilting angle. Moreover, the antimicrobial effects of the produced SLIPs using black seed oil were proven against Gram-positive Staphylococcus aureus ( S. aureus ) and Gram-negative Escherichia coli ( E. coli ).

Condensation widely exists in nature and industry, and its performance heavily relies on the efficiency of condensate removal. Recent advances in micro-/nanoscale surface engineering enable condensing droplet removal from solid surfaces without extra energy cost, but it is still challenging to achieve passive transport of microdroplets over long distances along horizontal surfaces. The mobility of these condensate droplets can be enhanced by lubricant oil infusion on flat surfaces and frequent coalescence, which lead to fast growth but random motion of droplets. In this work, we propose a novel design of diverging microchannels with oil-infused surfaces to achieve controllable, long-distance, and directional transport of condensing droplets on horizontal surfaces. This idea is experimentally demonstrated with diverging copper and silicon microchannels with nanoengineered surfaces. Along these hierarchical surface structures, microdroplets condense on the top channel wall and submerge into microchannels owing to the capillary pressure gradient in infusing oil. Confined by the microchannel walls, the submerged droplets deform and maintain the back-front curvature difference, which enables the motion of droplets along the channel diverging direction. Subsequent droplet coalescences inside the channel further enhance this directional transport. Moreover, fast-moving deformed droplets transfer their momentum to downstream spherical droplets through the infusing oil. As a result, simultaneous passive transport of multiple droplets (20-400 μm) is achieved over long distances (beyond 7 mm). On these oil-infused surfaces, satellite microdroplets can further nucleate and grow on an oil-cloaked droplet, demonstrating an enlarged surface area for condensation. Our findings on passive condensate removal offer great opportunities in condensation enhancement, self-cleaning, and other applications requiring directional droplet transport along horizontal surfaces.