Nitridation of a Si(100) surface by 100–1000 eV N+2 ion beams

Anti-Adhesion Behavior from Ring-Strain Amine Cyclic Monolayers Grafted on Silicon (111) Surfaces

In this manuscript, a series of amine tagged short cyclic molecules (cyclopropylamine, cyclobutylamine, cyclopentylamine and cyclohexylamine) were thermally grafted onto p-type silicon (111) hydride surfaces via nucleophilic addition. The chemistries of these grafting were verified via XPS, AFM and sessile droplet measurements. Confocal microscopy and cell viability assay was performed on these surfaces incubated for 24 hours with triple negative breast cancer cells (MDA-MB 231), gastric adenocarcinoma cells (AGS) endometrial adenocarcinoma (Hec1A). All cell types had shown a significant reduction when incubated on these ring-strain cyclic monolayer surfaces than compared to standard controls. The expression level of focal adhesion proteins (vinculin, paxilin, talin and zyxin) were subsequently quantified for all three cell types via qPCR analysis. Cells incubate on these surface grafting were observed to have reduced levels of adhesion protein expression than compared to positive controls (collagen coating and APTES). A potential application of these anti-adhesive surfaces is the maintenance of the chondrocyte phenotype during in-vitro cell expansion. Articular chondrocytes cultured for 6 days on ring strained cyclopropane-modified surfaces was able to proliferate but had maintained a spheroid/aggregated phenotype with higher COL2A1 and ACAN gene expression. Herein, these findings had help promote grafting of cyclic monolayers as an viable alternative for producing antifouling surfaces.

Damage mechanisms of MoN/SiN multilayer optics for next-generation pulsed XUV light sources

We investigated the damage mechanism of MoN/SiN multilayer XUV optics under two extreme conditions: thermal annealing and irradiation with single shot intense XUV pulses from the free-electron laser facility in Hamburg - FLASH. The damage was studied "post-mortem" by means of X-ray diffraction, interference-polarizing optical microscopy, atomic force microscopy, and scanning transmission electron microscopy. Although the timescale of the damage processes and the damage threshold temperatures were different (in the case of annealing it was the dissociation temperature of Mo2N and in the case of XUV irradiation it was the melting temperature of MoN) the main damage mechanism is very similar: molecular dissociation and the formation of N2, leading to bubbles inside the multilayer structure.