Gallium indium eutectic masking prior to porous silicon formation creates unique spatially-dependent chemistries.

We demonstrate that gallium indium (GaIn) eutectic can be used to create interesting crystalline Si/porous silicon (cSi/pSi) platforms that exhibit unique analyte- and spatially-dependent photoluminescence (PL) responses. Here we characterize these cSi/pSi regions by using profilometry, scanning electron microscopy (SEM), wide-field PL microscopy, and Fourier transform infrared (FTIR) microscopy. As we move along a vector from the cSi/pSi interface out into "bulk" pSi, the: (i) analyte-dependent, PL-based response initially increases and then decreases; (ii) total PL emission intensity, in the absence of analyte, increases; (iii) pSi thickness increases; and (iv) relative OSi-H to Si-H band amplitude ratio decreases.

Contact Pin-Printing onto Porous Silicon for Creating Microarrays with High Chemical Diversity.

We explore the size and spatial microheterogeneity of contact pin-printed spots formed on porous silicon (pSi). Glycerol was contact printed at room temperature onto as-prepared, hydrogen-passivated pSi (ap-pSi) using 50 or 200 µm diameter solid pins. The pSi was then subjected to a strong oxidizing environment (gaseous O) and washed to remove the glycerol masks.

Effects of Polyhexamethylene Biguanide and Polyquaternium-1 on Phospholipid Bilayer Structure and Dynamics.

Multipurpose solutions (MPS) are a single solution that functions to simultaneously rinse, disinfect, clean, and store soft contact lenses. Several commercial MPS products contain polyhexamethylene biguanide (PHMB) and/or polyquaternium-1 (PQ-1) as antimicrobial agents. In this paper we have created an in vitro small unilamellar vesicle (SUV) model of the corneal epithelial surface, and we have assessed the interactions of PHMB and PQ-1 with several model biomembranes by using fluorescence spectroscopy, dynamic light scattering (DLS), and liquid chromatography-mass spectrometry (LC-MS).

Extremely strong tubular stacking of aromatic oligoamide macrocycles.

As the third-generation rigid macrocycles evolved from progenitor , cyclic aromatic oligoamides , with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of > 10 M in CHCl), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of .

Aqueous self-assembly of giant bottlebrush block copolymer surfactants as shape-tunable building blocks.

Programmed self-assembly of well-defined molecular building blocks enables the fabrication of precisely structured nanomaterials. In this work, we explore a new class of giant polymeric surfactants (Mn = (0.7-4.