• Study of the rates of chemical reactions

• Three types:First OrderSecond OrderZero Order

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•Pharmaceutics

Cancer Treatments

Painkillers •Agriculture

Fertilization of crops

•Fragrances Air

freshener Bug

repellant

#1: Semi-permeable membranes and controlled concentrations can create a zero-order rate of diffusion.

#2: Polar membranes diffuse polar substances like alcohols at a zero-order rate.

J = mass fluxD = diffusion co-efficientdC = CIN - COUT

dX = thickness of membrane

(Ra)2 = 4(δD1-δD2)2 + (δP1-δP2)2 + (δH1-δH2)2

RED = Ra/Ro

δD = London dispersion forces

δP = Dipole-dipole interactions

δH = Hydrogen bonding

Ra = Solubility differenceRo = Solubility radiusRED = Relative energy difference

• Thickness vs. Polarity Constant thickness (40

mils) Varied polarity Hypothetically: more polar

membrane should increase diffusion rates of electrolytes

• Experimentation for film composition: Ethylene Vinyl Acetate

(EVA), Poly Vinyl Alcohol (PVA), Poly Ethylene Glycol (PEG)

30-40% EVA produced most uniform films

• The Process:1. Prepare the EVA solutions2. Prepare the Doctor Blade and

glass slides3. Cast films4. Dry in Oven

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• Strong Electrolytes– Sodium Chloride (NaCl)– Calcium Sulfate Dihydrate (CaSO₄ ∙

2H₂O)

• Weak ElectrolytesCitric Acid Ascorbic Acid Acetylsalicylic

Acid

147.76 g/100 mL 33.O g/100 mL 0.30 g/100 mL

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

-10

-5

0

5

10

15

20

Sodium Chloride

NaCl 40% EVA; 50 mils; 2000 range

NaCl 40% EVA; 25 mils; 2000 range

NaCl 40% EVA; 50 mils; 200 range

NaCl 40% EVA; 25 mils; 200 range

NaCl 40% EVA; 40 mils; 2000 range

Time (hrs)

Co

nd

ucti

vit

y (

µS

/cm

)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 200

5

10

15

20

25

30

35

Calcium Sulfate Dihydrate

CaSO4 40% EVA; 25 milsCaSO4 40% EVA; 30 milsCaSO4 40% EVA; 40 mils

Time (hrs)

Conduct

ivit

y (

µS

/cm

)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 500

0.0001

0.0002

0.0003

0.0004

0.0005

0.0006

0.0007Ascorbic Acid

Ascorbic Acid 35% EVAAscorbic Acid 30% EVA

Time (hrs)

H3O

+ C

once

ntr

ati

on (

mol/L)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 190

0.0005

0.001

0.0015

0.002

0.0025

0.003Citric Acid

Citric Acid 30% EVA

Citric Acid 35% EVA

Citric Acid 40% EVA

Time (hrs)

H3

O+

Co

nce

ntr

ati

on

(m

ol/

L)

0 5 10 15 20 25 300

1

2

3

4

5

6

Gravimetric Analysis of Alcohols

Methanol 40% EVA Linear (Methanol 40% EVA)

Propanol 30% EVA Linear (Propanol 30% EVA)

Ethanol 40% EVA Linear (Ethanol 40% EVA)

Ethanol 35% EVA Linear (Ethanol 35% EVA)

Ethanol 30% EVA Linear (Ethanol 30% EVA)

Time (Hours)

Ma

ss L

ost

(gra

ms)

• Strong electrolytes do not diffuse in up to 40% EVA membranes

• Most weak electrolytes do not diffuse, except for citric acid

• Methanol, ethanol, and propanol diffuse

• Pseudo zero order diffusion achieved

• Ionic membranes• Varied size of solutes• Specific range of polarity for

optimal diffusion

A Very Special Thanks to:

• Dr. David Cincotta, advisor• Tony Chen, assistant• Dr. Adam Cassano &

Dr. Steve Surace, co-directors• Anna Mae Dinio-Bloch,

Program Manager

Generous Financial Support from:• Laura (NJGSS ’86) and John Overdeck• NJGSS Alumnae and Parents of

Alumnae• State of New Jersey• Drew University• AT&T        • Celgene• Novartis• Independent College Fund of NJ• Johnson & Johnson• Bayer Healthcare• Actavis Pharmaceuticals• Board of Overseer’s, New Jersey

Governor’s Schools

Thank You!!!