One of the most commonly asked questions from our customers is the topic of shear rates and what to expect when dealing with various applications. Now most of you have a general idea on what shear rate means, but we want to take it one step further and illustrate several key components when dealing with shear rates.
One of the common questions we get from our customers is, “Which chip do I use to test my fluid?” RheoSense has a variety of different chips and you may wonder which chip would be the best for your application. The m-VROC® has four different designations of chips: A, B, C, and E. These letter values reference the max pressure capability of the MEMS pressure sensors inside the microfluidic flow cell. With the A-series being able to measure the lowest pressures for low viscosity fluids, the E-series are able to measure the highest pressures for higher viscosities and higher shear rates.
Recently I have been using polyurethane resins for sculpting and casting projects and noticed an interesting term on all of my materials: Pot life. This is something that you see in all kinds of applications from epoxies, silicone, sealants, and building materials. A cursory definition of the term indicated that it was the working life of the material – the cutoff time when you can no longer make adjustments or clean up your projects. However, I found that the material was still very workable beyond the pot life time – in fact for some applications it even worked better.
We are all familiar with maintaining our lab instruments, but how often do we perform maintenance on our lab methods or SOPs?
According to Cell Press, "Royal jelly is produced in [two different] glands of worker bees, one that produces the protein in a neutral pH and one that produces fatty acids that can reduce said pH when the two secretions" come together (Cell Press).
For a honeybee, royal jelly is a crucial diet for the first couple days for all bees. And for honeybee larvae to become queen, the larvae must be fed and be surrounded by royal jelly for it to morph successfully. However, because queen larvae, "are too big to fit into the cells of the hive's honeycomb," they are able to hang upside down in the queen's cell anchored with the royal jelly (Cell Press). So, what allows this royal jelly to acquire these properties?
Turns out, royal jelly is not always thick and sticky. In a recent study, researchers proposed that the viscosity of a royal jelly were dependent the particle size of a protein found in royal jelly (known as royalactin, or MRJP1) was directly correlated to the pH level found inside. The study conveyed that there was a noticeable size difference within the MRJP1 jelly when exposed to a purifier at pH 4 and at neutral (pH 7). For instance, "Most purification protocols are standardized at pH 7, [which yielded] a strange, runny consistency [within the jelly]" whereas when maintained between pH 4 and pH 5, the viscosity of the jelly seemed gelatinous and almost adherent (Cell Press). The precise pH affects the overall viscosity of royal jelly, which is an essential component in providing the optimal environment for the queen bee to develop in her early stages. If the pH levels were outside 4~5, the royal jelly would lose its heavy, sticky properties and would not be able to hold the queen larvae.
Laponite is an additive which is by definition, "a unique specialty additive; a layered silicate manufactured from naturally occurring inorganic mineral sources." The main purpose in which Laponite serves can be separated into two major uses:
1) Rheology Modifier — Laponite is added to various consumer products to improve stability; many products have been shear sensitive or thixotropic behavior. Laponite is often used as a thickener in cosmetics.
2) Film Former — Laponite produces film to create electrically conductive coatings
Aside from these two major uses, Laponite has been used in the healthcare industry as a bioink additive to hydrogels, enabling a habitable environment for stem cells and also playing a role in creating a biodegradable containment for drug delivery.
Not many people besides rheologist and scientist think much about viscosity, but it plays a very important roll in geology and geography. Check out this NASA article and next time you look at the landscape you might be thinking about viscosity.
A recent study has been released by brilliant researchers at Penn State. Upon careful research, it has been discovered that bacteria plays a role in viscosity. Solutions where bacteria is highly concentrated, it was observed that there was a decrease in viscosity. Initially thought to be a result of high concentrations, researchers dug deeper.
As a lubricant begins to breakdown it undergoes significant viscosity changes. These viscosity changes can play a critical role in the life and performance of moving parts. For example, knowing when to change the engine oil in a car is straightforward, every 3,000 to 5,000 miles is a good rule of thumb. Going beyond the recommended scheduled oil change runs the risk of critical component failure leading to engine damage. However, what if you don’t have a convenient method, like miles driven, to gauge the health of your lubricant? How will you know when the lubricant begins to breakdown? The solution to this is knowing your viscosity!
We have all read this click bait title many times over.
Yes, we are at the dawn of the autonomous revolution and ultimately, some jobs will be replaced by robots. The good news is that this revolution is going to accelerate science and technology at a rapid pace. The companies and individuals who invest and embrace automation will have a large competitive advantage over those who stick to traditional techniques.