Polymers

Traditionally in GPC, the sample dissolution solvent and the mobile phase are one and the same. However, a closer look at the demands of sample solvent and mobile phase suggests that this should not always be the case.

This article explores the role of different components within drilling muds, including barite and calcium carbonate. The need to achieve optimum particle sizes is examined, the application of laser diffraction is considered within this context. Fast, efficient and having a wide measurement range, laser diffraction delivers accurate, precise and reproducible particle size information. Offering automated analysis, it is a preferred method for drilling mud particle sizing and the focus of ongoing API efforts to develop a standard in this area.

The newest addition to the popular ‘10 ways to…’ series of educational papers provides practical guidance on developing high performance suspension products with enhanced consumer appeal. ‘10 ways to...control rheology by changing particle properties’ explores how controlling particle characteristics, such as particle size distribution, concentration and zeta potential, enables formulators to engineer suspension performance. Suspensions are used in the formulation of a wide range of every day products from medicines, drinks and foodstuffs to paints, inks and coatings. This paper is therefore valuable to formulators working across a wide range of industries.

The latest advances in the widely used technique of size exclusion chromatography (SEC) break new ground in terms of accuracy and sensitivity. This article assesses the information provided by multi-detector SEC and the potential benefits of recent innovations for polymeric food additive characterization.

A sample of PMMA was analysed by Size Exclusion Chromatography with Triple detection, before and after sterilization. Reduction in the molecular weight was shown to be firstly by cleaving the polymer at the branching points.

Triple detection GPC/SEC combines measurements from multiple detectors to offer not only increased amounts of data, but also increased amounts of information, which is made available by the combination of different detectors (and unobtainable using individual detectors separately). The theory of triple detection GPC/SEC is described here.

This application note describes the analyses of a variety of aqueous (water-soluble) cellulose derivatives using the OMNISEC triple detection system and the subtle, yet distinct differences between these different derivatives that can be parsed out by the OMNISEC system

In this application note, molecular weight data from the Viscotek SEC-MALS 20 is combined with measurements of Rg and IV to study the structure of different polysaccharides including pullulan, dextran, hydroxypropyl cellulose (HPC), pectin and gum Arabic. The differences between conformation and Mark-Houwink plots are also studied.

A smart poly(acrylic) acid shows promise as a carrier to improve anticancer drug action, says Alison Maniego

The Uwe D. Neue award recognizes the impact that breakthrough work by industrial scientists has on analytical science. 2015’s recipient is Mark Schure – and here’s why.