Superwettable porous spheres prepared by recyclable Pickering emulsion polymerization for multifarious oil/water separations

A low-cost, environment-friendly, and sustainable strategy for fabricating a superwettable porous polymer sphere is reported for the treatment of various kinds of oil-in-water and water-in-oil emulsions.

Functionalized Gold Nanoparticles Coated Polymer Spheres as SERS Substrate for the Detection of TNT Explosives

In this paper, we fabricated the 4-aminobenzenethiol modified gold nanoparticles onto polymer spheres as SERS substrate to selectively detect 2,4,6-trinitrotoluene (TNT) explosives. The gold nanoseeds were fixed on polymer surface by reduction of HAuCl4·3H2O with sodium citrate. About 60~100nm nanoparticles were formed from the previous seeds and self-assembled by 4-aminobenzenethiol. The functionalized gold nanopartilces aggregation coated on large polymer sphere surface not only absorbed more TNT molecules via conjugation system, but also generated numerous "hot spots". It was demonstrated that this substrate displayed high SERS activity for TNT detection. It could also be anticipated that the aforementioned material would be used for fast and sensitive SERS detection of TNT in real-world situation. Keywords: gold nanopartilces, SERS, TNT, functionalization

Experimental Study of a Creeping Polymer Sphere in Contact With a Rigid Flat

The creep of a polymer sphere contacting a rigid flat under a constant normal load is investigated experimentally. An optical technique is used to observe in situ the evolution of the contact area while the increase of contact interference is measured simultaneously. The experimental results obtained with polytetrafluoroethylene (PTFE) spheres of different diameters pressed against a sapphire flat under different normal loads are presented, and the effect of sphere diameter and normal load on the creep of the contact parameters is discussed. The present experimental study validates recently published theoretical results of a contact model for a creeping sphere and a rigid flat showing that a universal similarity solution exists for the dimensionless creep interference and dimensionless creep contact area as functions of the dimensionless time.

Experimental Study of a Creeping Polymer Sphere in Contact With a Rigid Flat

The creep of a polymer sphere contacting a rigid flat under a constant normal load is investigated experimentally. An optical technique is used to observe in situ the evolution of the contact area while the increase of contact interference is measured simultaneously. The experimental results obtained with PTFE spheres of different diameters pressed against a sapphire flat under different normal loads are presented and the effect of sphere diameter and normal load on the creep of the contact parameters is discussed. The present experimental study validate recently published theoretical results of a contact model for a creeping sphere and a rigid flat showing that a universal similarity solution exists for the dimensionless creep interference and dimensionless creep contact area as functions of the dimensionless time.