Question 1

How do high and low values of the selected physicochemical parameters (molecular weight, lipid solubility, physical state) affect absorption? Was your pre-game prediction correct/incorrect?

12. Continue to adjust parameters relevant to the performance of the detergent. 
Note: Performance is a measure of a chemical’s effectiveness. It tells us how well the detergent will do its job (a great cleaning ability). For detergents and soaps, performance is quantifiable through the hydrophilic-lipophilic balance (HLB). 

In this phase of product development, you will optimize the HLB. You should know that the HLB value will vary with the log P value selected during earlier design phases. Thus, changing the HLB value will also impact the absorption of the molecule. Make sure that while adjusting HLB, you don’t go out of preferred range for log P!

The consideration of multiple outcomes such as absorption and product performance is an example of the real-world constraints that may affect chemical product development

Question 2

Using the game outcome, what is the HLB “sweet spot” which enables the detergent to be an effective cleaner and be nontoxic?

Question 3

Why do you think Log P and HLB are depended on each other? Tip: recall detergent’s structure.

Question 4

Many detergents available on the market are designed for a specific function: be a good cleaning agent. As you can see from the game, it is relatively easy to control one parameter.
When a company decides to design a product with a dual function like safety AND high performance, the task becomes more challenging. Why do you think that is?

In the game, were you able to design a detergent that will not absorb and have a high performance? Was it easy or difficult?

Can you think of other examples of products from your daily lives, which perform a dual function?

13. Progress to Level 2 and begin by reading Overview, Goal and Gameplay tabs.
Note: Level 2 has three Challenges: Human Toxicity Challenge, Aquatic Toxicity Challenge and Performance Challenge. You will need to complete all three to successfully finish the game. Similar to Level 1, parameter selection is carried over to another challenge, since you are still developing one product with one set of parameters.

In this level, you need to design a chemical that will have a limited distribution, increased degradation and limited bioaccumulation. You will also notice that properties and chemical functional groups which control these processes are different than in Level 1.

14. Read the Task Description for Distribution and adjust four given parameters. Click Next to receive feedback.

Question 5

Which molecules (high or low surface area) will enhance distribution through the membrane and why?

15. Continue the Human Toxicity Challenge by completing Metabolism and Accumulation & Excretion Subtasks. 

Question 6

Which functional groups impair excretion and contribute to accumulation in the organism?

16. In Aquatic Toxicity Challenge, you are asked to select up to 3 functional groups which enhance biodegradation. You can access that feature by clicking on the arrow button in the Functional Groups window. Make sure to scroll down to access all the functional groups you can choose from.

Question 7

Why does branching play a critical role in biodegradation of the chemical?

17. Once you complete Aquatic Toxicity Challenge and receive feedback, please proceed to Performance Challenge. This time the HLB value which you see is the result of your functional group selection in the earlier challenge. If your HLB value is out of the preferred range, you need to change functional groups by clicking Edit Functional Groups. Please remember that your re-selection will also impact Aquatic Toxicity Challenge result.

Question 8

Do the same functional groups that enhance biodegradation (Aquatic Toxicity Challenge) contribute to the increased performance? 

As future chemists, why do you think this is important to consider different functional groups and the role they play in the design process?

What if instead of two parameters (safety and performance) you also need to consider cost as a third parameter?

This material is based upon work supported by the NSF Division of Chemistry and the Environmental Protection Agency under Grant No. 1339637.