Question

A fashion technologist wants to speed up the dyeing of cotton. According to diffusion principles, what step will most effectively increase dye penetration?

• A. Lowering the temperature to reduce dye movement
• B. Increasing temperature to enhance molecular diffusion
• C. Using ice water to lock colour
• D. Decreasing dye concentration

Answer 1

The Correct Option is B

Concept:

• Dyeing works on the principle of diffusion, dye molecules move from the high-concentration dye bath into the low-concentration fibre until the two sides equalise.
• Raising temperature gives dye molecules more kinetic energy, so they move and collide faster, and it also swells open the fibre structure so molecules can enter more easily.
• Both effects together speed up how fast dye reaches deep inside the cotton fibre.
• Cooling the bath, using ice water, or lowering dye concentration all work in the opposite direction, they slow the process or are used for a different purpose like fixing colour, not for speeding up penetration.

Step 1: Identify the driving factor in diffusion-based dyeing.
Dye penetration speed depends mainly on molecular movement, and molecular movement depends directly on temperature and on the concentration gradient.

Step 2: Check the temperature-lowering options first.
Lowering temperature and using ice water both reduce molecular energy, this slows dye movement instead of speeding it up, so these work against the goal.

Step 3: Check the concentration option.
Decreasing dye concentration reduces the gradient that pushes dye into the fibre, this also slows diffusion, so it is wrong too.

Step 4: Confirm the correct step.
Increasing temperature speeds up molecular motion and opens the fibre structure, both effects push more dye into the cotton faster, which is exactly what the technologist wants.

Final Answer: Increasing temperature to enhance molecular diffusion