Sample homogenisation is crucial for an experiment’s success. When it fails, it can be extremely troublesome for researchers.
To avoid this problem, use the most reliable laboratory homogenizers and refine your work process. But first, you should understand why homogenisation often fails and how to stop this from happening.
When Equipment Isn’t the Problem
Most of the time, you do not need to replace the entire equipment range to see improved results. The equipment is not the problem.
Setup choices
Upgrading your equipment will never be the solution if it originates from setup problems. A more powerful dispenser will only magnify the poor setup choices. Then, the upgrade will simply be a waste of money.
The scaling problem
A process that works seamlessly for a small sample can fail miserably for a larger study group. When you scale up, it is essential to adjust the settings accordingly to avoid sample homogenisation problems.
Understanding failures
When you face issues in an experiment, the first step should always be identify the culprit. An upgrade will only solve your problems if the issue is hardware-related.
Physical and Chemical Properties of the Sample
Let’s take a look at how physical and chemical properties can affect your lab sample preparation.
Viscosity
Check the dispensers’ viscosity limit. Extremely high viscosity may reduce shear transfer’s effectiveness.
Density
Large density gaps between phases will resist uniform dispersion. Therefore, particles may not be evenly distributed by shear.
Particle hardness
Particles that are too soft may be deformed or broken during the process. On the other hand, particles that are too hard will not be dispersed effectively unless you mill them first.
Operational Mistakes
Even if the system is mechanically fine and set up correctly, it can still fail due to operational mistakes caused by workers.
Improper immersion depth
When the dispersing depth is insufficient, it will lead to air entrainment and foaming. In contrast, if it is too deep, it will cause poor circulation and dead zones.
Incorrect tool sizing
There should be a suitable rotor–stator gap for functionality. Be careful about choosing the right head design for emulsions and suspensions as well.
Processing time
Avoid jumping directly to the maximum RPM, as it can create surface-only shear. Many systems work best with staged homogenisation. Check the guidelines before setting the process time.
Limitations of High-End Dispersers
High-end dispersers may not solve all your problems if they didn’t come from the dispersers in the first place.
Localized shear zones
Without the right settings, even top-spec dispersers can bring shear problems by offering surface-level-only mixing. Materials outside of the localized zones will have to be transported manually.
Scale needs
As you scale up, you must adjust different settlings according. Simply upgrading the equipment will not enhance efficiency. In most cases, it might even drag down performance.
Stability
High-power input does not guarantee stability. Sample homogenisation is multi-fold and requires precision from all aspects. Instead of spending money on an upgrade, it might be better to refine the current process.
Environmental and External Factors
Aside from lab sample preparation and mixing quality, make sure you have the following environment and external factors under control. They ensure the research is conducted in a safe, functional space.
Temperature control
Unstable temperature fluctuations can cause viscosity to change drastically. Labs must provide a stable environment for temperature control to avoid polluting or invalidating the samples.
Contamination
Samples can be contaminated by oil, dirt, or residues from previous testing rounds. Having safety protocols and cleaning routines can effectively prevent sample contamination.
Moisture
Some samples can be more susceptible to moisture than others. Not keeping the moisture level stable can cause homogenisation issues.
Practical Solutions
It can be annoying when sample homogenisation fails. Don’t worry. Here are a few practical solutions to help with the issue.
Control the process
Set out a meticulous process guide that covers every step researchers should follow. It eliminates mistakes caused by different standards and preferences. A standardized process control guarantees fairness and outcome quality.
Validate homogeneity
Do not rely on the visuals to determine homogeneity. Oftentimes, the results can be misleading. Use tools and various indicators to verify the results and readings. Measure particle size, concentration uniformity, and stability to highlight key areas that usually cause problems
Use appropriate tools
Partner with trusted lab equipment providers like IKA to install state-of-the-art tools for your research center. A trusted provider can recommend appropriate tools based on your research needs.
In conclusion
While it is tempting to think that a high-end disperser will fix all your homogenisation problems, in reality, the issue is usually much more complex.
To ensure sample homogenisation, you should use appropriate tools and control the process.
