How do I structure my sophomore year science project regarding cellulose extraction from pencil shavings?

[kkvvaann8]

Hello everyone,

I am working on a project involving the extraction of cellulose from pencil shavings using an alkali treatment (NaOH) followed by bleaching with NaOCl. The main aim is to investigate how the concentration of the sodium hydroxide solution affects the yield of cellulose obtained.

The issue I am running into is the time required for the procedure. In an earlier project, I performed three successive NaOH treatments of 10 minutes each before proceeding to the bleaching stage. The alkali treatment alone therefore took 30 minutes. Including washing steps and 2–3 bleaching treatments, a single batch takes roughly 1.5 hours to process.

Ideally, I would like to perform the extraction in triplicate for each NaOH concentration in order to obtain reliable yield data. However, with four different concentrations, this would require about 18 hours of laboratory work, whereas I only have access to the chemistry lab for around 1.5 hours in 1 day.

I am therefore looking for advice on experimental design. Would it be better to:
1. Keep multiple NaOH concentrations but reduce the number of replicates, or
2. Keep triplicate trials but investigate fewer concentrations?

Also, for yield assessment, I am considering using Schweizer's reagent to dissolve the extracted cellulose and then measuring the mass of any insoluble residue. I have not used this reagent before, so I would be grateful for any comments on whether this approach is practical and whether it would provide a meaningful estimate of cellulose yield.

I would also appreciate suggestions for alternative variables or measurements that could make the project more interesting while remaining feasible within the available time.

Any other suggestions would also be greatly appreciated.

[ameyab19]

Hi,

Regarding keeping replicates vs concentrations, with your time constraints, fewer concentrations with replication might be helpful. If you were to run 4 NaOH concentrations, it might be harder to account for variation, but with triplicates, you would have more statistical comparisons and less lab work. You could also double-check with a supervisor or teacher for another opinion.

About Schweizer's reagent: I did some research, and it's great for dissolving cellulose but definitely requires a lot of precision and prep. You could go forward with this, but since your project focuses on yield, you could consider gravimetric yield % (mass of dried cellulose / mass of raw shavings * 100).

Here's a link with some more info - https://chem.libretexts.org/Ancillary_M ... xperiment). In short, you'd probably dry and weigh the raw shavings, run the extraction, dry and isolate the cellulose and weigh, then calculate yield %.

If your equipment permits, you might be able to process multiple samples at the same time, such as washing all the samples together or bleaching several samples simultaneously.

I'm not an analytical chemist, but the info above might have some guidance that could help. You could also definitely check with a supervisor/teacher to see whether the protocol would work/alternate options.

Good luck and hope your project goes well!

- AB