NTU MSE JC2 Outreach Programme: Day 4 and Day 5

Yesterday was day 4 of the attachment programme, which makes today the fifth. A word to describe these two days would be 'more', since louis and myself were both able to visit more labs in the school, try out more new science equipments, brainstorm about more ideas, as well as eat more food around the campus.

Notices at a food court that made me feel glad that the consumers' safety are being cared for

Fantastic-looking meal enjoyed by Louis

As in chronology, let us begin this blog post by recapping our activities in day 4. Right in the morning, we went to basement 4 of the school to take a look at the workings of the transmission electron microscope (TEM). It is basically the extraordinaire in the world of microscopes, as its magnification can be increased to even via materials on an atomic scale (an atom is approximately 0.3nm in diameter). Somehow paradoxically, the TEM is surprisingly big although it essentially deals with small things (o.o).
Then, we went back to the lab to collect our freeze-dried 3D PAN sponge that we've electrospun last week. Upsettingly, i do not have a picture of the spongy material (oh crap!), but fret not, i'll describe, to the best my limited language ability allows, its features. Well, then again i realised that describing the material requires negligible language at all, the material entirely resembles fluffy cotton balls we have at home. The material is almost weightless, and is extremely soft that i don't think i felt it. Amazing material I say :)
After that we hurried down to the furnace room, which is a room meant for all degrees of heat. Remember the PAN polymer mat we prepared earlier? Well, we were there at the furnace room exactly for the purpose of heat-treating the PAN polymer mat to form a pure carbon mat. Prof mentioned that under high temperatures under inert conditions, these polymer nanostructures will be chemically altered to form pure amorphous carbon.

Equipment used to heat-treat the PAN nanofibre mat

Expensive-looking equipment we saw nearby. Seems ideal for heating gases.

The heat treatment had to take a few hours, and we eventually came back to the furnace room one day later (today) to collect the product. Once again, i left my camera elsewhere and shall rely on my fantastical language ability to paint an image of the pure carbon mat to you readers. It is a black, brittle, flat piece of material. If you happen to inherit itchy hands, you'll find that your fingers get a lil' black after touching the carbon mat. Be glad that this time it doesn't kill you and please do rid of that bad habit.
The next experiment we required us to deal with another microscope. This microscope is an optical microscope, which is, in other words, a-unimpressive-after-you've-seen-a-TEM kind of microscope. Still, me and louis had fun toying with it, and also received kind guidance from Dr Kong's colleague.

An optical microscope

A strand of hair under the optical microscope

Well, the rest of day 4 was spent on discussions for the ultimate presentation, BUT, we're not going to disclose anything. We're keeping the suspense alright! Just wait for it. Muahaha.

Let us chop chop and move on to day 5. Highlight of day 5: lithium-ion battery assembling.

Cranky face Louis

Smiles

Free hugs machine

Highly pure Argon gas tank

The creepy handshake

Haha, pictures truly speak a thousand words huh? The excess of our self-obsessed pictures and the lack of the pictures of the battery assembling procedure clearly shows how BORING battery assembling is haha. Well, actually it isn't entirely boring, i only yawned 3/4 times. If I haven't remembered wrongly, the way to assemble is like this:

Battery Base --> Aluminium conductor --> lithium electrode --> Separator --> Pure Carbon or infused with MoS2 electrode --> Copper conductor --> Spring --> Battery Cover

(FYI: We made four batteries, two of them using the carbon mat we've prepared from PAN yesterday, the other two using a sample that contains carbon and MoS2.)

A liquid electrolyte was added to within the battery as well. The battery is then sealed using a hydraulic cringer.

Following that, we then tried out the Scanning Electron Microscope (SEM) to take a real good look at our leftover PAN nanofibre mat.

Ghostly hand of Dr Kong

Lovely backdrop seen on the neighbouring monitor

A strand of PAN nanofibre as seen from a magnification of x200000

A nanofibre mess observed at x3000

As Dr Kong pointed out, the PAN nanofibre strand is not porous and that is why the fibre strand still appears rather smooth on its surface. Polyester he said, is on the other hand much more porous. For elctrospun nanofibres, the pores originate from the evaporation of solvent in the electrospinning process. I guess for different materials, there exist different extents of adhesion between the solvent and the polymer, causing different degrees of porosity in the nanofibres. For polyester nanofibres, since the nanofibres are already very thin to begin with, the pore sizes will be even smaller. Louis and I have thought of leveraging on the small pores in the nanofibres to induce greater capillary effect in polyester materials. Sounds legit, but we'll need to work on this more to make it a fully fledged idea. Oh ya, we saw this adorable graffiti in the SEM room as well.

Pigs in the best light

We're ending soon, stay with us for a niffy more please! Last event of the day: the necessary evil, the fire drill in the school of MSE. Fortunately the weather was cooperative, otherwise you'll see me tearing my head. Actually it was pretty fun though, we had selcas and also managed to visit the bottom-most floor for the first time.