Malvern Instruments Limited

Malvern Panalytical Inc.

Fraser McNeil-Watson

Robert Jack

Jason Corbett

Malcolm Connah

David McKnight

Malcolm Trevor Connah

The invention relates to methods and apparatus for determining properties of a surface. Embodiments disclosed include an apparatus for measuring a surface charge of a sample, comprising: a sample holder having an opposed pair of electrodes and configured to hold a sample in position in a measurement volume between the electrodes such that a planar surface of the sample is aligned orthogonal to the electrode surfaces; a measurement chamber for containing a measurement liquid and having an open end configured to receive the sample holder to position the electrodes in a preset orientation; a laser light source positioned and configured to direct a laser beam through the measurement chamber between the electrodes and parallel to the planar surface of the sample when the sample holder is received in the measurement chamber; and a detector positioned and configured to detect scattered light from the measurement volume, wherein the apparatus is configured to allow for detection of the scattered light by the detector over a range of distances from the surface of the sample.

Surface charge measurement

Methods and apparatus for measuring particle characteristics are disclosed. In one aspect, an amount of light arising from interaction between light and a suspended sample is detected simultaneously with the acquisition of a photon count from a different direction. At least one measure of particle characteristics can then be derived based at least in part on timing between information from the steps of acquiring and detecting.

Light scattering measurements using simultaneous detection

A high-throughput optical suspension characterization instrument is disclosed, which can include hydraulically separate and at least partially transparent sample containers. A selection mechanism is operative to selectively direct light from a light source () through different ones of the sample containers along an optical axis, and an off-axis scattering detector () is responsive to scattered light from the light source after it has interacted with a sample. Phase analysis light scattering is used to determine the electrophoretic mobility and zeta potential of samples. A second instrument is disclosed, wherein all sample containers are illuminated simultaneously. Transmitted light is collected by a camera. The electrophoretic mobility and hydrodynamic size of the samples may be determined.

Apparatus for high-throughput suspension measurements

In one general aspect, a multi-sample liquid scattering measurement apparatus is disclosed. It includes a coherent light source having an optical output axis, with sample cells that each include a volume that intersects with the optical output axis. Detectors are each positioned to detect scattered light resulting from an interaction between light from the coherent light source and one of the cells. Light scattering analysis logic is responsive to the detectors and operative to determine a property of a liquid sample in each of the sample cells based on the detected scattered light.

Multi-sample scattering measurements

In one general aspect, an instrument for measuring characteristics of particles suspended in a fluid is disclosed. It includes a closed wall surface defining a fractionation channel having a input opening, an output opening, and a flow axis that spans downstream from the input opening for the channel to the output opening. A force application subsystem has a force application output oriented perpendicular to at least part of the flow axis of the fractionation channel. A particle characteristic measurement subsystem is located hydraulically downstream from at least a portion of the closed wall surface defining the fractionation channel, and includes a sensor positioned to sense a property of the suspended particles in the potential measurement subsystem as well as a signal output responsive to the sensor. A result processor has a signal input responsive to the signal output of the particle characteristic measurement subsystem, zeta potential processing logic responsive to the particle characteristic measurement subsystem, and a particle characteristic signal output responsive to the particle characteristic processing logic.

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Malvern, United Kingdom

Fraser McNeil-Watson