Quantifying biofilm propagation on chemically modified surfaces

Conditions affecting biofilm formation differ among bacterial species and this presents a challenge to studying biofilms in the lab. This work leverages functionalized silanes to control surface chemistry in the study of early biofilm propagation, quantified with a semi-automated image processing algorithm. These methods support the study of Pantoea sp. YR343, a gram-negative bacterium isolated from the poplar rhizosphere. We found that Pantoea sp. YR343 does not readily attach to hydrophilic surfaces but will form biofilms with a “honeycomb” morphology on hydrophobic surfaces. Our image processing algorithm described here was used to quantify this honeycomb morphology over time and displayed a logarithmic behavior in the propagation of the honeycomb biofilm. This methodology was repeated with a flagella-deficient fliR mutant of Pantoea sp. YR343 which resulted in reduced surface attachment. Quantifiable differences between Pantoea WT and ΔfliR biofilm morphologies were captured by the image processing algorithm, further demonstrating the insight gained from these methods.

Adsorption and sensing of CO and NH3 on chemically modified graphene surfaces

We have studied the electronic structure and adsorption characteristics of environmentally potent gaseous molecules like carbon monoxide (CO) and ammonia (NH3) on chemically modified surfaces of graphene, employing ab initio density functional methods.

Current Progress on the Surface Chemical Modification of Carbonaceous Materials

Carbon-based materials is considered one of the oldest and extensively studied research areas related to gas adsorption, energy storage and wastewater treatment for removing organic and inorganic contaminants. Efficient adsorption on activated carbon relies heavily upon the surface chemistry and textural features of the main framework. The activation techniques and the nature of the precursor have strong impacts on surface functionalities. Consequently, the main emphasis for scientists is to innovate or improve the activation methods in an optimal way by selecting suitable precursors for desired adsorption. Various approaches, including acid treatment, base treatment and impregnation methods, have been used to design activated carbons with chemically modified surfaces. The present review article intends to deliver precise knowledge on efforts devoted by researchers to surface modification of activated carbons. Chemical modification approaches used to design modified activated carbons for gas adsorption, energy storage and water treatment are discussed here.

Pattern Collapse of High-Aspect-Ratio Silicon Nanostructures - A Parametric Study

This work focuses on capillary-induced collapse of high-aspect-ratio silicon nanopillars. Modification of the surface chemistry is demonstrated to be an efficient approach for reducing capillary forces and consequently reduce pattern collapse. Special effort is spent on determination of the wetting state of chemically modified surfaces as complete structure wetting is of utmost importance in wet processing. In light of this, an ATR-FTIR based method has been developed to unambiguously distinguish between wetting and non-wetting states.