“Do not be deceived: Bad company corrupts good character.” Says 1 Corinthians 15:33. We have all been there- some people/ friends in this world have somehow enticed us into certain situations which are compromising to our beliefs. We are then left with a choice: to follow or to walk (sometimes run) away.
Colloidal nanoparticles are similar in nature (without the choice part). A beautiful, stable colloid is one in which nanoparticles are uniformly dispersed within a medium (e.g. water). This is like the suspension of gold nanoparticles in the cuvette (holder) on the left in the image below.
To achieve this uniform dispersion, each of the nanoparticles should be happy to occupy their own space. This is either by: 1) surface charge repulsion, where surfaces of the nanoparticles are negatively charged (or all positively charged) and therefore repel each other, or 2) steric hindrance, where bulky functional groups on the nanoparticle’s surface reduce the opportunity of other nanoparticles getting close (aggregation). The functional groups which provide the charge or bulky groups are known as a capping agent.
For us as Christians, that capping agent is our belief. It is what keeps us stable in our relationship with God and ideally our beliefs should not be compromised. In remaining with our belief in God, we perform at our best, which is the same as these colloidal dispersions. Magnetic iron oxide nanoparticles are being studied for cancer treatment via hyperthermia. This is where these nanoparticles are injected into the site of the tumour, an external magnetic field is applied so the nanoparticles align with the field and when the field is removed, these nanoparticles relax back to their original orientation, releasing heat along the way and blasting the tumour cells! Okay… so there is a bit more to it but the functionality is only possible in the stable form of the colloid. Please feel free to read further on magnetic hyperthermia: doi:10.1016/j.rpor.2013.09.011 (open access source from what I know).
Now when the capping agent is removed (e.g. by light or heat etc), the nanoparticles agglomerate, which is natural to them (i.e. most thermodynamically stable) since the surface tension is reduced. However, upon clustering together, their density becomes greater than the medium they are in and they flocculate together to the bottom of the holder (see the right cuvette in the image above). This creates an unstable colloid, which is not useful.
In biblical language: “Do not be unequally bound together with unbelievers [do not make mismatched alliances with them, inconsistent with your faith]. For what partnership can righteousness have with lawlessness? Or what fellowship can light have with darkness?” (2 Corinthians 6:14, AMP). When we cosy with people who do not share our faith principles and neither respect them, we are dragged down into an unstable relationship with God. So let us be aware that our capping agent is always on before we get too close to bad company for, “how blessed is the man who does not walk in the counsel of the wicked, nor stand in the path of sinners, nor sit in the seat of scoffers! But his delight is in the law of the Lord, And in His law he meditates day and night.” (Psalm 1:1-2).