User:Samiye Yaman/Notebook/Lab 581/2013/02/06

Objective

Description

• Hydrogels synthesized on 01/02/2013 was transferred from -20C to room temperature.

Part A Synthesizing Phosphate Buffer

• Concentration Needed; 20mMol
• pH Needed: 7.4
• pka: 7.3m
• base: sodium monophosphate
• acid: sodium diphosphate

• Acid + Base= 20 mmol therefore Base= 20mmol-acid

• pH= pka+ log (base/acid)

• (20mmol-acid)/acid= pH/pka

(Base/acid)=1.25.

• Acid=8.85mmol & Base= 11.15mmol

Mass used for base: (119.98 g/mol)* 0.01115mol= 1.338g

Mass used for acid: (141.96 g/mol) * 0.00885mol= 1.256g

• Add 1.25 g of sodium diphosphate and 1.34g of sodium monophosphate in to a 900ml of miliQ water. (Stir well to make sure it is completely homogeneous). Ph needs to be 7.4 so 0.5M of sodium hydroxide was added drop by drop to make sure Ph reaches to 7.4.

Part B Dissolving PVOH with phosphate buffer

• 0.51 g of PVOH (MW:89000-98000) was placed in to a beaker with 5 ml of water. It was placed in to a hot plate with temperature of 120C.(stir well to dissolve PVOH completely).Add 2µ of R6G.

Part C

• 100ml of mineral oil was placed in to a homogenizer. Add 0.5 g of PVOH with phosphate buffer(prepared at part A) in to the homogenizer and homogenize it for 5 minutes. Pour it in to a beaker and place it in to a freezer at -20C for 20 hours.then thaw for 4 hours.

Data

Notes