Influence of n-alkanes on wettability and zeta potential of quartz

367

INFLUENCE OF n-ALKANES ON :VETTABILITY AND ZETA POTENTIAL OF QUARTZ

BronlsLew

JARCZUK and

Em11 CHIBOWSKI

Department of Physical Maria Curie-Sktodowsks 20-031 Lublin (Poland) Received

17 August

Chemistry, University,

1984;

Institute of Chemistry. Merie Curie-SkZodoweka

accepted

2 October

Square

1904

ABSTRACT Contact angles were meesured in the following systems: quartz/water droplet/eatureted vapor of water + n-elkane and quartz/water droplet/saturated vapor of n-alkane. The slkanee tested were from hexene to pentmdecane. In both systems non-smooth changes of contact angl.e as a function of the chein length were These changes are similar to the zeta-potential changes observed. measured previously for two different samples of quartz in the quartz/n-alkane/wster syetem.On the basis of the results and calculations it is suggested that the observed non-smooth changes of contact angle are due to similar changes in film pressures of the water and n-alkenee.

INTRODUCTION Many aspects

great

that

the

their

adaorbed

energetic

phase,

even

of

water

the

ionleation

forces nay

0254-0584/85/$3.30

properties

water

state

molecule ), the

Influence

surface

is

not

the

can

different

from

adsorption

there

bulk

organic

water

the

eubetances.

F-S]

bulk

. As a result

the

first

two

hydration

In effect, [13]and

of

ordered

L7,B,ll] for

still

measuremente

in

dispersion,

[7,8,12,23].

with of

of

are

relatively

(eepeclmlly

ratios

quartz

ldeorption

monolayers

change

be wetted

water are

ldeorption

reciprocel

of

molecules

up to 11 etatfetical

monolsyers

surface

the

fl-1YJ . For example,

interest

ehor and

of

the

and quartz

this

may also

Molecules

of

0 Elsevier Sequoia/Printed

in The Netherlands

3.

368

non-polar water The

e or

clusters magnitude

of

the

and

free

of

from

the

results

the

system

from

concluded

in

their

of

wettability

contact

angles,

quartz/water

water

5.8.141.

and

polar

components

depends film.

of

surface the

the

on the This

with

length

melting

force

n-alkane

chain

odd and

quartz/n-al-

detachment

and

their

of

the

potential

n-alkane

nsture

was concluded

in

the

wetted

zeta

to

films

cl5-13.

stability change

temperature

even

of

[18],

n-alkanes

may

structures.

additional

on the

surface

among adsorbed of

measurements

a quartz

that

film

dispersion

measurements

show that

is

surface

hydrocarbon

a way similar

in

the

quartz

from

as a function

To obtain

in

zeta-potential

:15-171

non-smoothly,

differ

the

and

bubble

The

it

of

system

an air

changes

of

quartz

on a monolayer

an adsorbed

results

kane/water

and

the

of

on the

perhaps,

energy

thickness

of

may adsorb

liquid

results

8f In

quartz

the

on the

influence

surfaces,

systems:

droplet/saturated

measurements

quartz/water vapor

of

of

n-alkane were

made of

droplet/air

n-alkane

films

and

+ water.

EXPERIMENTAL Measurements surface

were

lesoopa

system

Two series plate of

placed

In

of several

this

tasted.

with

the l-2

angles sessila

measurements in

the

in

times

way a series

volume

on the of

of

method 25

box

n-alkanes

and

In

from

a gonloaeter-te-

the with

first,

a quartz

saturated

these

after

right

on a quartz

times.

containing Then,

with

filled

was settled

left

droplets

conducted.

measuring

before.

water

drop

were

A vessel

box a day rl

of

magnification

and n-alkane. in

droplet

contact

made by the

was placed

water

read

of

of

liquids

had

s.

20 mins.,

the

contact

and

sides hexane

of to

the

vapor bean

a water angle

was

droplet,

pentadecane

was

369

In

the

placed

second

in

the

Contact

placed

glass

cell.

times

in

the

which was

ware

250

at

molecular

sieve

were

made

at

ring

cell

1 ,*

washed ‘C

In

for

and

lh.

20 + 0.1

Oc

saturated

plates

(1:l

j,

All

in the

( double

vapor

was

the

plate

from

were

boiled

In

both.

Then

three disti-

they

filled

angle

had

a quartz

doubly

a desiccator

contact

+ 5z1

were

then

ultrasonic

placed

was

(4W

eater used

the

plate

sieve

mins.

plates

solution a water

quartz

molecular 20

quartz

R + 5 13).

(4

by

measurements acid

the

n-alkane

taken

The

the

hydrochloric and

only removed

box.

Before

measurements

of

readings, in

water

heated

in

vapor

angle

been

lled

box

:Vater

present.

series

were with

measurements

theremostating-room

and

measu-

RESULTS AND D ISCUSS ION Measured function

contact the

of

angles

number

of

are

presented

carbon

in

atoms

in

Figs.

the

1 and

n-alkane

2 as

a

chain.

5,mV

25 6 Fig.

I 7 8 NUMBER 1.

Dependence

(curve

2 ) on

quartz

glass/water

(contact film/water

I 1 I I I I -.-30 9 10 11 72 13 IL 15 OF CARBON ATOMS, n of

n-alkane

contact chain

angle length

droplet/saturated

angle)and

ground

( zeta

potential).

quartz

1 ) and

(curve determined

vapors ( Poland,

in

zeta

the

of

water

stored

dry

potential

aystems: + n-alkane )/n-alkane

).

7 0 NUMBER Fig.

2.

Dependence

quertz

glass/water

angle

( tete

Curve

potent

ted

vapor

the

quartt/water

are

also

of

Brazilian

and

Fig.2

were obtained

n-alkane

As is

seen

change

the

dry

purity, f roe

systems: {contact

wetf/n-aiksne

quartz/water

sy8tem,

changes

of

film/we-

presented

stored

more

In a very

curve

1’ ( Fig.2

) for

vapor

system.

There

potentiel of

then

for

in

measured

natural and

1 word obta%ned

quartz

those

(from

presented neesurements

water.

Both

samples of

99.994;.

and 2,

similar

detarmined

quartz,

fn Fig.

ricroelectrophoresis

quartz,

droplet/eatura-

ayetem.

fn a desiccator,

Figs.1

zeta

samples

method

from

and

n-alkane

potentials

potential

Brazilian high

for

f ilrlwater

of zeta

was stored

8f

n-alkane

two different

, for

which

angles

results

quertz/n-slkans

natural

vapor

of

potential

zeta

in the

(stored

droplet/eaturetad

by the streaming

1’ Iand

determined

1.

ial

water

[16?

Result8

i curve

length quartz

shown in the Figs

previously

angle

chain

1 (Fig.ifshows

in the

contact

droplet/saturated

ground

f and

were

of

n-elkene

2’)on

(curve

ter

9 I2 13 1.4 15 OF CARBON ATOMS, n

zeta

potentials

way for

and

contact

the same eaaple.

Poland), in for quartz

However, they differ changes

of

the contact

n-alkane vapor

tad of

quartt

in

the

stored

system

kane system stored So, in

dry

system in water

similar

is

well

to ret8

pretreatasnt.

there

the surfece

and their

Therefore,

if

the

end polar

surface

the

than

properties

mutual

quartz

that

is

adsorption

snd

qurrrtz

polar

+ n-al-

quartz

potential). be expected

is

exposed

not

its

to water

place

energeti-

on the sample

and ionogenic

determines

could

of

depend

sites

on

properties.

snd n-alkane

on suitable

in chsnges

these

water

in Fig.1.

of

c%n take

messured

of

could

strongly

relation

the surface

vapor

(streaming

of

chenges

1 ; those

n-alkane

tha surface

its

interactions.

potenti8f

changes

This will reflect

surface.

to zet8

Moreover,

droplet/satura-

potential

%re hydrophobic,

coapetitive

vapors,

with

fn Fig.2

and

quartz/water

droplet/saturated

known thst

ho~og~n~oua

the

themselves.

(microelectrophoresis

and then wetted

preeented

in

between

%re similar

quartz/water

are

the case

cally

of

angles

8 more hydroxyleted

It

considerebly

sites

in the dispersion

be qualitatively

explained

by a modified Young's equation:

&Jf - T-e1 = YQfW + 3;r co30

where

TQf

is

the surface

film of n-alkane pressure

on the

energy

of

wster,

8 is

If

the

quartz

contect

&I surface

surface

‘Keg, ).

engle free

is

TQfM is ?&

of

Te,

is

the

of

n-alkane film

interfacial

the surface

the water

energy

the

the

droplet.

free

tension and

Tel

qU%rtZ/n-8lk8ne

of is film

vapor.

a geometric

intersctions

( TOP - yQ -

qu%~tx/n~alk8ne/w%ter~

the decrement by weter

free energy of quartz covered with a

is

atean for assumed

the

[19.201

interfacfal

dispersion

and recognizing

that

and polar n-alkane

372

influences then

only

from

the

! 1 Ione

eqn.

where tension vely

.

of

I water

change

-

and

the

surface

Tel

and

from

zero

to

tension

the

theoretical surface

ne2,

).

-

Then

contact range

In

the

rated

vapors

of

changes

conditions

: curve

curve

“TTe,

II.

of

presented

- ‘;’

?fpd

spreading

wetting

of

n-slkane

: curve

III,

this <

ITe,

on

the

The

parameters ?*d

follows: Tw = 72.0 In

Pig.3

of

=

TQd

there

n-alkane

used

for

- 76

ma/m2

mJ/m2: are

from %,

surface

-

W5

&;

the

7-W” also

on

;

the

quartz

[19] = 21.8

presented

;

pQp

mJ/m2

contact

ne,

the

covered <

-%;

TQ

-

work

‘&,:

of

with -

ITe,

;i?;,;I::,

-

of

surface.

= 115

and

following

?&-


setu-

(2 ))curves

is

( eqn.

calculations

water

the =

The

a quartz

(eqn.

quartz

;-$1_<

wetting

) and

-

will

discussed.

example

7”:

n-alka-

yOf

Tel

rs

,“~~;2~*~22=;H:a>

spreading

-

to

on

result

a

can

the

changes

;z12;wwater

and

is

Te,

zero

Particular

yQd

respecti-

*rH is

system

an

Fig.

surface

angle

) , and

Te,

angle

Fig.3.

0 < Te,

e2 y

w5 = 2 \/(

).

droplet/air

contact

from

the

(as

the

quartz,

( where

of in

of

Te,

change

relation

in

_

?&

can

hexane

in

I,

5

contact

presented

( -fad

quartz/water

the

( Tel

value

water

presence is

Tel

angle

of

f

TTe,

the

the

system

8=

of

energy

in

that

vapors

? qd

quartz

components free

results

TW. Therefore,

determine

8

dispersion

it

of

obtain:

the

of

TTe, =

ten

) t n-alkane

surface

interactions

are

eqn.(2)

vapor

function

ne

water

From

dispersion

( 2 )) are mJ/m2

3;Np f angle

[ii]

51 mJ/n2 changes

as

; [is]

( dotted

.

373

Fig.

3.

Calculated

functfon

of

changing

betmaen

’ eqn.

water

iTe, the

f

12)) values and n-alkmne

following

of

the f Tit,

cantect angle as a 1 film pressures.

boundaries.

I 0 < Tie, < YQd I+; 7TeI =O Curve II 753, f 0; ws f Te, f 7"*- ?& Curve Iff Te2 = PQd - TH; Ws 4 T6, 4 To - ITe, - ?& Curve IV fihp = Wsw: kVS< %iei ,( ?a - VYsHL Tw. Line 1 sPhow8the 8 values in the quartz g~esafwatef droplet/water + Rexane vapbrs system.

Curve

2 shows

Line

lint

the

0

values

in

the

qusrtr

glms/weter

droplet/n-

vapor system.

hexans

) for

vapors

the

( curve

syatemst

shown

the

systenr

and

the

and

also TTei values.

In other

t&e

experiments1

words,

possibie,

dr~p~et~w~te~

i ) and quartz/water

From Fig.3 it ia ten

quartz/water

for

depending

in

that

the contact

8 given on

the

dropler/hexane

theoretical

region

ainglee

339, Tfa,

vepor

contect

bordered

cm

= canst., values,

by

resulr

+ hexsne

sngle

curves.

from

many 0

( curve values f.l;I

various

2 1, in

and IfX, ?b2

vsXues at-a

and the experimental

374

(measured

) value

values.

of

However.

may be connected

0

the

TTe2 to

ITe,

with

ratio

is

many

Te2

exactly

and

ve

1

determined.

CONCLUSIONS On the that

basis

of

non-smooth

n-alkane

the

changes

chain and

the

n-alkanes,

iij

ITe,

eech

for

the

with

the

water

for

vapor

= const.

it

contact

may occur

n-alkanes

of

water

n-alkanes

changes

and

can

angle three

the

as

a function 1)

changes

n-alkane

iii

be concluded

instances:

adsorption

tested,

vapor

) Tfe,

non-smoothly

for

film and

of

the

Tte,

=

particular

thickness change

ITe,

the

observed

contact

changes,

of

themeselves

in

results

contact

for

However, measured

kness

reached

the

further

film

of

n-alkanes

the

To explain

for

However , the angles

results

on the

on the of

and zeta

behavior, studied

quartz-glass

Ingram potentials

changes

differ

water

vapor,

Ve,

as

studied

to 1-4

Ingram

plate

[ 221 support presented

from

the

of [221

silica. studied

thic-

The films

to heptane:

a function

fused

the

out.

by elfpsometry. pentane

however,

nm and the

this

the

n-alkans

proposed This

in

a

seems

this

in aome way the in

and

between

be predicted

has

In

that

individual

decreased as

adsorption

conclusion

values

[22]

nm for

thickness

such

to

wetted

the

potential

cannot

silica

non-smoothly

layer

possible

Ingram

15-20

that

and 2 \ point

thickness

on fused

thickness

l-re,

surface

the

due

without

( Fig.1

angles.

length.

be hardly

and

film

films

and

Tel

n-alkane

surface

changes

with

changes

gel-like

contact

are

thickness

chain

zeta

angle

angles

contact

the

supports

course,

n-alkane

of

. Also,

! showed

and 2 ) . This

systems

the

on a quartz

to hexadecane

1211

same way ( Figs.1

1Te,

adsorption

i hexane

the

for

calculations

n-alkane.

Studies

the

of

length

= constant

changes

above

paper.

to

paper.

375

REFERENCES 1

J.1. Vhalen, J.Phys. Chem.. 65

(1961' 1676.

2

3. Rubio and J.A. Kitchener, J. Colloid (1976' 132.

3

H.K. Bernett and W.A. Zismann. J. Colloid Interface Sci., 29 '1969' 413.

Interface Sci., 57

4

F.M. Fowkes. 3. Colloid Interface Sci., 64 11978' 36.

5

A.M. Khall. J. Colloid Interface Scl., 68 '1979' 357.

6

M.P. Aronson. M.P.Petko end H.M. Prlncen, J. Colloid Interface 3ci., 65 :1978; 296.

7

F.M. Fowkes. 'Ed.). Hydrophobic Surfaces, Academic Press. New York-London, 1969.

8

F.M. Fowkes, J. Collold Interface Sci., 28 (1968 )493.

9

R.N. +amb and D.N. Furlong. J. Chem. Sot. Faraday Trans. I.78 1982, 61.

10

R.L. Ewery, W.H. Wade and N. Hacheoman, J.Phys. Chem., 65 (1961) 25.

11

P. Stasrczuk. 0. Jariczuk and E. Chibowski, submitted for publicetion.

12

8. Jariczuk. Przem. Chem., 61 (1982' 468.

13

8. Janczuk. E. Chibowski and T. Bia2opiotrowicz. for publication in J. Colloid Interface Sci.,

14

K. Klier and A.C. Zettlemoyer. (1977) 216.

15

E. Chibowski and L. Holysz, J. Colloid Interface Sci.. 81 (1981) 8.

accepted

3. Colloid Interface Sci., 58

16

E. Chibowski, Prrem. Chem., 59 (1980) 606.

17

B. Janczuk, Powder Technology, 34 (1983) 243. W-wa 3974 [in Polish] .

18

Poradnik Firykochemicrny,WNT,

19

F.M. Fowkes. Ind. Eng. Chem.. 56 (1964) 40.

20

s. wu. J. Polym. Sci., Part. 34. (1971) 19.

21

P. Staszczuk, Mater. Chen. Phys. 10 (1984! 473.

22

0.T. Ingram, 3. Chen. Sot. Farady Trans. I, 3 il974) 868.