Hidden Second Oxidation Step of Hummers Method

Blister formation during graphite surface oxidation by Hummers’ method

Graphite oxide has a complex structure that can be modified in many ways to obtain materials for a wide range of applications. It is known that the graphite precursor has an important role in the synthesis of graphite oxide. In the present study, the basal-plane surface of highly annealed pyrolythic graphite (HAPG) was oxidized by Hummers' method and investigated by Raman spectroscopy and atomi...

2016 - a second step

1. Disciplina de Pneumologia, Instituto do Coração – InCor – Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo (SP) Brasil. 2. Editor-Chefe, JBP, Brasília (DF) Brasil. The role of the editorial board of a scientific journal goes beyond deciding what should or should not be published on the basis of scientific merit; it must include identifying needs in the are...

Kinesin's second step.

We have identified dimeric kinesin mutants that become stalled on the microtubule after one ATP turnover, unable to bind and hydrolyze ATP at their second site. We have used these mutants to determine the regulatory signal that allows ATP to bind to the forward head, such that processive movement can continue. The results show that phosphate release occurs from the rearward head before detachme...

High-efficient Synthesis of Graphene Oxide Based on Improved Hummers Method

As an important precursor and derivate of graphene, graphene oxide (GO) has received wide attention in recent years. However, the synthesis of GO in an economical and efficient way remains a great challenge. Here we reported an improved NaNO3-free Hummers method by partly replacing KMnO4 with K2FeO4 and controlling the amount of concentrated sulfuric acid. As compared to the existing NaNO3-free...

Step-by-Step Programming with Base SAS 9.4, Second Edition