Resilient and compressible three‐dimensional nanomaterials comprising polymers, carbon, and metals have been prepared in diverse forms. However, the creation of thermostable elastic ceramic aerogels remains an enormous challenge. We demonstrate an in situ synthesis strategy to develop biomimetic silica nanofibrous (SNF) aerogels with superelasticity by integrating flexible electrospun silica nanofibers and rubber‐like Si−O−Si bonding networks. The stable bonding structure among nanofibers is in situ constructed along with a fibrous freeze‐shaping process. The resultant SNF aerogels exhibit integrated properties of ultralow density (>0.25 mg cm−3), temperature‐invariant superelasticity up to 1100 °C, and robust fatigue resistance over one million compressions. The ceramic nature also endows the aerogels with fire resistance and ultralow thermal conductivity. The successful synthesis of the SNF aerogels opens new pathways for the design of superelastic ceramic aerogels in a structurally adaptive and scalable form.
Disinfecting drinking
water in a reliable, sustainable, and affordable
manner is a great challenge, especially for water contaminated with
pathogenic microbes, and traditional water disinfection strategies
still suffer from biofouling, irreversible depletion of disinfectants,
and energy consumption. In this study, we developed biomimetic and
superelastic skeletal-structured silica nanofibrous aerogels (SNAs)
with rechargeable bactericidal and antifouling property via the combination
of electrospun silica nanofibers and a functional Si–O–Si
bonding network. The premise for our design is that the Si–O–Si
network comprising rechargeable N-halamine moieties
can provide the aerogels with structural stability yet durable bactericidal
activity. The resulting aerogels exhibit intriguing properties of
high porosity, superhydrophilicity, superelasticity, rechargeable
chlorination capability (>4800 ppm), and exceptional bactericidal
activity (99.9999%), enabling the aerogels to effectively disinfect
the bacteria-contaminated water with ultrahigh flux (57 600
L m–2 h–1) and antifouling function.
The synthesis of the SNAs opens pathways for exploring antibacterial
and antifouling materials in a renewable and nanofibrous form.
Resilient and compressible three‐dimensional nanomaterials comprising polymers, carbon, and metals have been prepared in diverse forms. However, the creation of thermostable elastic ceramic aerogels remains an enormous challenge. We demonstrate an in situ synthesis strategy to develop biomimetic silica nanofibrous (SNF) aerogels with superelasticity by integrating flexible electrospun silica nanofibers and rubber‐like Si−O−Si bonding networks. The stable bonding structure among nanofibers is in situ constructed along with a fibrous freeze‐shaping process. The resultant SNF aerogels exhibit integrated properties of ultralow density (>0.25 mg cm−3), temperature‐invariant superelasticity up to 1100 °C, and robust fatigue resistance over one million compressions. The ceramic nature also endows the aerogels with fire resistance and ultralow thermal conductivity. The successful synthesis of the SNF aerogels opens new pathways for the design of superelastic ceramic aerogels in a structurally adaptive and scalable form.
Bioprotective materials
with bactericidal activity could largely
protect healthcare workers from being infected by emerging infectious
diseases; however, creating such materials has turned out to be extremely
challenging. Here, we fabricate a novel polysulfonamide (PSA) N-halamine electrospun nanofibrous membrane with rechargeable
and rapid bactericidal properties by a Lewis acid-assisted chlorination
process. The hydrogen bonds between PSA molecular chains can be weakened
through Lewis acid–base complexation during chlorination, enabling
more available amide groups to be chlorinated into N-halamine biocidal groups. The resulting nanofibrous membranes render
intriguing features such as rechargeable chlorination capability (>4500
ppm), rapid bactericidal activity (6 log reduction of bacteria in
1 min), high particle removal efficiency (>99.8%), long-term durability,
and ease of scalable production, which can be perceived as a functional
layer of protective equipment that is capable of not only intercepting
but also inactivating the pathogens effectively. The successful synthesis
of the PSA N-halamine antibacterial nanomaterials
opens new ways toward the development of bioprotective materials in
a multifunctional and rechargeable form.
The healing of chronic wounds, which bring profound problems, can be effectively promoted by skin tissue engineering using scaffolds with features of extracellular matrix (ECM) for supporting native cell growth. Protein ultrafine fibrous scaffolds, although with similar morphology and chemical composition to ECMs, show poor wet stability which leads to substantial deformation, low mechanical properties, and fast degradation. This research provides a two-step dry state treatment including a cross-linking process by ethylene glycol diglycidyl ether (EGDE) and a blocking process by lysine for the modification of zein ultrafine fibrous scaffold model. This distinctive two-step dry state treatment could effectively avoid fiber deformation before fully cross-linking and more importantly the concern of cytotoxicity. The modified zein/EGDE scaffolds displayed remarkable reduced shrinkage of merely 1.25%, enhanced thermal stability, improved mechanical properties around 3−4 fold, retardant degradation to above 60 days, and promoted cytocompatibility about three fold. This work revealed the possibility to develop strong, wet stable, and cytocompatible ultrafine fibers from various proteins for a wide variety of applications in the fields, such as, tissue engineering scaffolds, biosensors, and drug carriers.
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