Icing imposes a significant burden on those living in cold climates, with negative impacts on inf... more Icing imposes a significant burden on those living in cold climates, with negative impacts on infrastructure, transportation, and energy systems. Over the past few decades, a wide range of materials...
Capillary wicking drives liquid motion in miniature channels and capillaries, which are omniprese... more Capillary wicking drives liquid motion in miniature channels and capillaries, which are omnipresent in the human body and technology such as the brain’s capillary network, plants, power systems, na...
Water-ice transformation of few nm nanodroplets plays a critical role in nature including climate... more Water-ice transformation of few nm nanodroplets plays a critical role in nature including climate change, microphysics of clouds, survival mechanism of animals in cold environments, and a broad spectrum of technologies. In most of these scenarios, water-ice transformation occurs in a heterogenous mode where nanodroplets are in contact with another medium. Despite computational efforts, experimental probing of this transformation at few nm scales remains unresolved. Here, we report direct probing of water-ice transformation down to 2 nm scale and the length-scale dependence of transformation temperature through two independent metrologies. The transformation temperature shows a sharp length dependence in nanodroplets smaller than 10 nm and for 2 nm droplet, this temperature falls below the homogenous bulk nucleation limit. Contrary to nucleation on curved rigid solid surfaces, ice formation on soft interfaces (omnipresent in nature) can deform the interface leading to suppression of ...
In the past decades, the omnipresent bacterial attachment and biofilm formation on surfaces have ... more In the past decades, the omnipresent bacterial attachment and biofilm formation on surfaces have facilitated the transmission of infectious diseases on global scale, inflicting significant public health concern and financial burden. Among the most affected surfaces, polyurethane (PU) based coatings used in wide range of human-touching settings were profoundly influenced by bacterial adhesion. To eliminate the undesired bacterial attachment on PU coatings, we designed a novel zwitterionic polyurethane (ZPU) with high content of sulfobetaine zwitterionic moieties for enabling surface hydrophilicity to hydrophobic acrylic polyurethane (APU) via an inter-diffused structured coating. The diffusion between ZPU and the underlying APU base ensures long-lasting surface hydrophilicity by allowing the zwitterionic moieties to be anchored into the interior of the coating films. Moreover, the excess ZPU on the surface during inter-diffusion also enhanced biocompatibility by quenching the toxic i...
Icing imposes a significant burden on those living in cold climates, with negative impacts on inf... more Icing imposes a significant burden on those living in cold climates, with negative impacts on infrastructure, transportation, and energy systems. Over the past few decades, a wide range of materials...
Capillary wicking drives liquid motion in miniature channels and capillaries, which are omniprese... more Capillary wicking drives liquid motion in miniature channels and capillaries, which are omnipresent in the human body and technology such as the brain’s capillary network, plants, power systems, na...
Water-ice transformation of few nm nanodroplets plays a critical role in nature including climate... more Water-ice transformation of few nm nanodroplets plays a critical role in nature including climate change, microphysics of clouds, survival mechanism of animals in cold environments, and a broad spectrum of technologies. In most of these scenarios, water-ice transformation occurs in a heterogenous mode where nanodroplets are in contact with another medium. Despite computational efforts, experimental probing of this transformation at few nm scales remains unresolved. Here, we report direct probing of water-ice transformation down to 2 nm scale and the length-scale dependence of transformation temperature through two independent metrologies. The transformation temperature shows a sharp length dependence in nanodroplets smaller than 10 nm and for 2 nm droplet, this temperature falls below the homogenous bulk nucleation limit. Contrary to nucleation on curved rigid solid surfaces, ice formation on soft interfaces (omnipresent in nature) can deform the interface leading to suppression of ...
In the past decades, the omnipresent bacterial attachment and biofilm formation on surfaces have ... more In the past decades, the omnipresent bacterial attachment and biofilm formation on surfaces have facilitated the transmission of infectious diseases on global scale, inflicting significant public health concern and financial burden. Among the most affected surfaces, polyurethane (PU) based coatings used in wide range of human-touching settings were profoundly influenced by bacterial adhesion. To eliminate the undesired bacterial attachment on PU coatings, we designed a novel zwitterionic polyurethane (ZPU) with high content of sulfobetaine zwitterionic moieties for enabling surface hydrophilicity to hydrophobic acrylic polyurethane (APU) via an inter-diffused structured coating. The diffusion between ZPU and the underlying APU base ensures long-lasting surface hydrophilicity by allowing the zwitterionic moieties to be anchored into the interior of the coating films. Moreover, the excess ZPU on the surface during inter-diffusion also enhanced biocompatibility by quenching the toxic i...
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Papers by Sina Nazifi