The concept of slippery lubricant-infused surfaces has shown promising potential in antifouling for controlling detrimental biofilm growth. In this study, non-toxic silicone oil was either impregnated into porous surface nanostructures, referred as liquid infused surface (LIS), or diffused into a polydimethylsiloxane (PDMS) matrix, referred to as a swollen PDMS (S-PDMS), making two kinds of slippery surfaces. The slippery lubricant layers have extremely low contact angle hysteresis and both slippery surfaces showed superior anti-wetting performances with droplets bouncing off or rolling transiently after impacting the surfaces. We further demonstrated that water droplets can remove dust from the slippery surfaces thus showing a "cleaning effect". Moreover, "coffee-ring" effects were inhibited on these slippery surfaces after droplet evaporation, and deposits could be easily removed. The clinically biofilm-forming species P. aeruginosa (as a model system) was used to further evaluate the antifouling potential of the slippery surfaces. The dried biofilm stains could still be easily removed from the slippery surfaces. Additionally, both slippery surfaces prevented around 90% of bacterial biofilm growth after 6 days, compared to the unmodified control PDMS surfaces. This investigation also extended across another clinical pathogen, S. epidermidis, and showed similar results. The anti-wetting and anti-fouling analysis in this study will facilitate the development of more efficient slippery platforms for controlling biofouling.

Biofilms are central to some of the most urgent global challenges across diverse fields of application, from medicine to industries to the environment, and exert considerable economic and social impact. A fundamental assumption in anti-biofilms has been that the coating on a substrate surface is solid. The invention of slippery liquid-infused porous surfaces—a continuously wet lubricating coating retained on a solid surface by capillary forces—has led to this being challenged. However, in situations where flow occurs, shear stress may deplete the lubricant and affect the anti-biofilm performance. Here, we report on the use of slippery omniphobic covalently attached liquid (SOCAL) surfaces, which provide a surface coating with short (ca. 4 nm) non-cross-linked polydimethylsiloxane (PDMS) chains retaining liquid–surface properties, as an antibiofilm strategy stable under shear stress from flow. This surface reduced biofilm formation of the key biofilm-forming pathogens Staphylococcus epidermidis and Pseudomonas aeruginosa by three–four orders of magnitude compared to the widely used medical implant material PDMS after 7 days under static and dynamic culture conditions. Throughout the entire dynamic culture period of P. aeruginosa , SOCAL significantly outperformed a typical antibiofilm slippery surface [i.e., swollen PDMS in silicone oil (S-PDMS)]. We have revealed that significant oil loss occurred after 2–7 day flow for S-PDMS, which correlated to increased contact angle hysteresis (CAH), indicating a degradation of the slippery surface properties, and biofilm formation, while SOCAL has stable CAH and sustainable antibiofilm performance after 7 day flow. The significance of this correlation is to provide a useful easy-to-measure physical parameter as an indicator for long-term antibiofilm performance. This biofilm-resistant liquid-like solid surface offers a new antibiofilm strategy for applications in medical devices and other areas where biofilm development is problematic.

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Under mild conditions of room temperature and pressure, and using either pure oxygen or air, aldehydes are converted using a heterogeneous Fe-N/C catalyst to produce the corresponding organic peroxy acid...

The current route in the UK for the conditioning and immobilization of most intermediate level waste for interim storage and geological disposal is to encapsulate in a cementitious matrix. However, certain waste materials, such as those containing reactive metals (e.g. uranium and aluminium), can corrode in the presence of the highly alkaline water in a cementitious environment. In their initial, undegraded form, polymeric materials can provide the appropriate, unreactive environment needed for the encapsulation of chemically active metals.This study examines the effects of gamma radiation on the stability of six candidate polymeric encapsulants, including a vinyl ester styrene resin (VES) and five epoxy resin formulations. The polymeric encapsulants were exposed to radiation doses up to 10 MGy using AMEC's cobalt-60 gamma irradiation facility and their radiation and chemical stability characterized by the use of a number of analytical techniques. These included flexural and compressive testing, Fourier transform infrared spectroscopy (FTIR), gel fraction, leach testing and gas evolution. The results show that the most stable resin in terms of radiation resistance and chemical stability was VES. Most of the epoxy resin materials also showed good generic stability, but the FTIR analysis showed the potential for doserate effects in one formulation.