Although protein adsorption on solids is of immense relevance, experimental limitations mean there is still a remarkable lack of understanding of the adsorption mechanism, particularly at a molecular level. By subjecting 240+ molecular dynamics simulations of two peptide/water/solid surface systems to statistical analysis, a generalized molecular level mechanism for peptide adsorption has been identified for uncharged surfaces that interact strongly with the solution phase. This mechanism is composed of three phases: (1) biased diffusion of the peptide from the bulk phase toward the surface; (2) anchoring of the peptide to the water/solid interface via interaction of a hydrophilic group with the water adjacent to the surface or a strongly interacting hydrophobic group with the surface; and (3) lockdown of the peptide on the surface via a slow, stepwise and largely sequential adsorption of its residues, which we term 'statistical zippering'. The adsorption mechanism is dictated by the existence of water layers adjacent to the solid and orientational ordering therein. By extending the solid into the solution by ~8 Å and endowing it with a charged character, the water layers ensure the peptide feels the effect of the solid at a range well beyond the dispersion force that arises from it, thus inducing biased diffusion from afar. The charging of the interface also facilitates anchoring of the peptide near the surface via one of its hydrophilic groups, allowing it time it would otherwise not have to rearrange and lockdown. Finally, the slowness of the lockdown process is dictated by the need for the peptide groups to replace adjacent tightly bound interfacial water.

27Keywords: Li-S battery, high volumetric capacity, monodisperse, interconnected carbon 28 nanospheres, close-packed 29 30We report a Li-S battery cathode of high volumetric-capacity enabled by novel micro-and meso-31 structuring. The cathode is based on monodisperse highly porous carbon nanospheres derived from 32 a facile template-and surfactant-free method. At the mesoscale, the nanospheres structure into 33 interconnected close-packed clusters of a few microns in extent, thus facilitating the fabrication of 34 dense crack-free high areal sulfur loading (5 mg cm -2 ) cathodes with high electrical conductivity 35 and low cathode impedance. A combination of the nitrogen doping (5 wt%), high porosity (2.3 cm 3 36 g -1 ) and surface area (2900 m 2 g -1 ) at the microscale enables high sulfur immobilization and 37 utilization. The cathode delivers amongst the best reported volumetric capacity to date, above 38 typical Li-ion areal capacity at 0.2C over 200 cycles and low capacity fading of 0.1% per cycle at 39 0.5C over 500 cycles. The compact cathode structure also ensures a low electrolyte requirement (6 40 µL mg -1 ), which aids a low overall cell weight, and further, amongst the best gravimetric capacities 41 published to date as well. 42

Protein adsorption is of wide interest including in many technological applications such as tissue engineering, nanotechnology, biosensors, drug delivery, and vaccine production among others. Understanding the fundamentals of such technologies and their design would be greatly aided by an ability to efficiently predict the conformation of an adsorbed protein and its free energy of adsorption. In the study reported here, we show that this is possible when data obtained from nonequilibrium thermodynamic integration (NETI) combined with steered molecular dynamics (SMD) is subject to bootstrapping. For the met-enkephalin pentapeptide at a water-graphite interface, we were able to obtain accurate predictions for the location of the adsorbed peptide and its free energy of adsorption from around 50 and 80 SMD simulations, respectively. It was also shown that adsorption in this system is both energetically and entropically driven. The free energy of adsorption was also decomposed into that associated with formation of the cavity in the water near the graphite surface sufficient to accommodate the adsorbed peptide and that associated with insertion of the peptide into this cavity. This decomposition reveals that the former is modestly energetically and entropically unfavorable, whereas the latter is the opposite in both regards to a much greater extent.

Importance of surface chemistry. Carbon, 78, Additional Information:• This paper was accepted for publication in the journal Car- AbstractNanoporous carbons with graphitic domains were synthesized from a polymer containing sulfur and nitrogen. The materials were characterized using adsorption of nitrogen, potentiometric titration TA/MS, XPS, TEM and XRD. Then they were tested as supercapacitors in threeelectrode cell and under visible light irradiation after extensive wetting either in water or a sulfuric acid electrolyte. The capacitance up to 450 F/g was measured in spite of a relatively low surface (<850 m 2 /g). The surface chemistry, and especially sulfur and nitrogen containing functional groups, were found of paramount importance for the capacitive behavior and for the effective pore space utilization by the electrolyte ions. Photocurrent measured in light also affects the capacitance. Its generation is linked to the excitation of sulfonic/sulfoxide chromophores-like moieties decorating the surface of the polymer-derived carbons.3

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