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6/01 c:/CIRC/DateDue.p65-p.15

I _ ._ _ 7 7 _ _-_ ._ __

mmsamnmrmmmmm
mm CAPE!!! (l' SILICA GIL

A Tho-10
Sub-1M to the Faculty

Of

liohignn Stat. 00110;.
In Mid runabout of the
Begun-cunts for the negro.

of

Wrath”

DOW of Chant-try

By

(HF

Joseph Jiflqupor
192‘!

.yrl

‘l‘

mamma- ICU

It hao boon round that if on aquoouo oolution of a oilicato
bo troatod with tho oquiwalont quantity or an acid, froo oilicio acid
and a oalt aro forlod. 'rhio oilioic acid la in tho colloidal otato,
and not in tho tom of a oinplo diooolwod man... I: this ayoton bo
allcwod to otand undioturbod, tho oilicic acid prooont will oxhihit ito
inoolubility, and a sol will for. oconor or 1601' nnlooo tho niwturo io
wot-y diluto. Tho opood or golatiou dopoudo upon ooworal factoro, along
which arc, oxcooo of acid or alkali prooont, tomoraturo, agitation, tho
kind of acid uood, and my othoro, all or which contributo to tho final
proportioo at tho sol.

Conoidorablo invootigation hao boon carriod out roux-ding oilio-
ic acid solo both with roopoct to thoir proparation and thoir proportioo.
It wao found that tho sol upon drying oxhibitod tho rolarkablo proporty
d‘ holding cortain onbotancoo omits ourtaoo. i'hio proporty had boon ob-
oorwod in many othor oubotancoo, along which waa a diatuacoouo oarth or
Xiooolghu-Sl) found in arm. dopooita in my looalitioo and eon-mm;
ct oilioom oholotono or diatuo, tho oilica of which won doriwod fro-
tho wator in which tho diatuo livod. thio oarth woo uood as a docoloriaor,
and will aboorb ooworal tinoo ito woight ct wotor.

ll'ho poculiar proporty oxhibitod by tho driod oilicio acid sol
or holding foroign oubotanooo on its curtaco, io knoum ao adoorpbion. ac
diotinguiohod fro. abocrpbiou. Inanmh ao thio proporty io inortant
tron both tho aciontif‘ic and cmrcial otandpoioto, Itch roooarch has boon
douo with tho wiow of diocovoring, if pcooiblo, tho boot nothod od' propor-
ing a sol which will oxhibit minu- adocrption.

10025“?

-1-

(2)

Moorption appoaro to bo larsoly a phyoical phonanoncn and
io inflnoncod in nany wayo. in oilioic acid solo oxhibit thio proporty
to a sroator or looo dosroo, which proporty varioo with tho nothcd or
proparation. In wiow of tho fact that tho variationo in proparation of
solo aro practically intinito, and that ovon aftor tho sol hao boon ob-
tainod conditiono or dryins have a tronondouo offoot on tho adoorptivo
capacity, it ia not onrprioins that any contradictory roporto havo boon
pnbliohod rosardins oilioa sol.

none-$3) in 1913. found that by varyins tho concentration of
hydroson and hydroxyl ion, ho could control tho opood of solution. In
hio roooarchoo ho proparod a valuablo tablo in which ho sivoo tho conoon-
tration at a nubor of aoido, both orsanic and inorsanic, which 'whon
nixod with oqual woluaoo d' ocdiun oilicato oolntion of a siwon ratio
of Iago - Bio; will prodnco a sol which will act in any lonsth of ti-
dooiroda

Grotto-(4)

produood a hydroool or oilioic acid by niwins tosothor
oqual volunoo od’ ton por cont oclutiono or oodiun oilicato and hydro-
chloric acid. Bo thon pnritiod tho hydroocl by dialyoio, coins hio ranouo
hoop dialyaora Thoush ouo work had boon dono boforo hio tilo on thio
oanoot, no oyotonatio roooaroh io ovidont, oo tho hiotory of oilica sol
ohonld proporly dato tra tho oxporinonto of Graham

Golo havo boon proparod at a mob oarlior dato than thcoo pro-
parod by Brahma. though thoir natnro won but wasuoly onopoctod. In 1773
Bat-o boliovod that ho had cbtainod a oolnblo for: of oilioa by troatins
oiliciu mutt: dittoront aoido. Boraolino, in 1830, proparod solo
in omral difforont wayo, anon; which ho mporatod a nixtnro or air.

and B O, which finally oot to a sol. lbolnm, in 1845, nado a sol by

2
hydrolyoio od' othyl ortho oilicato. In 1861, Booqnoral producod a plat-

inouo oilioa by olootrolyoio of potaooiun oilioato. Plouy, in 1866,
produood a sol uoins a oilioato and acotic acid. Othoro, includins
Icnior (1865) and llounior (1391), havo proparod solo of oilioic acid by
various nothodo.

Bolnoc and Andorom“) havo proparod a oilioa sol by procipitat-
ins oilioa and oxidoo of iron tosothor and than diooolvins tho iron out
of tho sol by acido. Thoy claiu that thio sivoo a vory aotivo sol duo to
tho offoct ct tho iron onidoo on poro formation.

Patrick and HoGavack draw) aftor a oorioa of oxporinonto with
803 and oilioa sol, docidod that tho oaoo with which a sac condonooo, pro-
notco adocrptim. it that tho thoy hold tho thoory that ncioturo omtont
of tho sol dotorninod ito activity as on adoorbont.

float of wottins wao otudiod by Patrick and Grin-,m by inoroins
tho sol in difforont liquido. Thoy account for tho hoot liboratod by a
dooroaoo in ourfaoo onorsy duo to diminution of intorfaoial tonoion bo-
twoon tho otruotural wator of tho sol and tho liquid olployod for immor-
oion.

Patrick and Davidhoioor“) invootisatod tho adoorption of In;
by oilioa sol with tho purpcoo in viow of otudyins tho naturo of tho oaall
amnto of wator loft in tho sol aftor activation. 1'hoy concludod that
tho wator contont had but littlo offoot, ao thoy producod a sol contain-
ins ac low as 0.333 820 which was but olishtly loco activo than thooo
containins concidorably larsor onounto.

Holnoo, Kaufman, and licholao“) otudiod tho vibrationo in
sol colt-no, and found that vibration froquoncy varioo diroctly as tho
conoontration of oilioic acid, inoroaoins with ninoral acido and dooroao-
ins with crsanic aoido.

Bovoral authoro havo oucccodod in obtainins cryotalo fro. both
tho hydroool and hydrosol of oilioic acid. ‘rhio was acooupliohod at hishor
tonporaturoo howovor, and aftor prolcnsod hoatins. Thoush thooo oryotalo
havo boon fox-nod at hish tonporaturoo, thoy would undoubtodly for: at
ordinary tonporaturoo, thoush vory olowly. It io boliovod that voin quarto
'wao fornod by a sradual prooooo of dohydration, an a oonvincins part of
thio prooooo can bo roproduood in tho laboratory. [any sono aro probably
forlod in tho oano nnnor. Bilicic acid in a noro or loan hydratod for.
coma in naturo ao opal, chaloodon, asato, hydrophano, otc., and in tho
vosotablo kinsdu ac tabaohir. fiydrophano and tabaohir cloooly roooiilo
artificial solo, boins ooro or looo tranoparont. according to wator contont.
Liooosans hao ohown that asato hao probably boon producod frou a sol of
oilioic acid into which layoro of iron and othor oalto havo ponotrurtod.

To tho soolosiot a workins nothcd of duplicatins nany ouch prooooooo of
naturo, io of sroat valuo.

Undor ordinary oonditiono tho oilioic acido arc of tho woabot
of inorsanio acido. Orthooilicic acid roadily booaoo convortod into ito
anhydrido and wator, thio boins roadily facilitatod by boatins. uuoh in-
vootisation hao boon. oarriod out to dotoruino tho oxaot conpooition of tho
hydratod oilioa. Grahanuo) found that by caroful dryins of tho purifiod
hydrcool of oilioic acid in vacuo, and furthor dryins ovor oonoontratod
11280” tho rooultins product had a cupcoition corroopondins to tho fornula
“02.320. thin. I“ lator vorifiod by c. Rom-tau” in 1868. Variouo
hydratoo havo boon cbtainod in difforont nannoro, corroopondins to tho
formlao 28i02.m20, ”102.2320, 38i02.320, and isionizO. Garnolloy and
lalkor( 12) found that in dohydratins a oauplo of carofully proparod oilioic
acid sol, thoro wac ouch a olisht chanso in tho rato at which wator wao

sivon off, that tho boliof in tho oxiotonoo of any dofinito hydrato woo

not juotifiod. rhoy furthor concludod that oilioa io a polynorido with
tho fornula (BiOgh. Tho valuo d‘ 3 wao found by Babonocffu'a) to lay
botwoon ooo and 1000, which would sivo tho nolocular woisht of thio c.-
pound on oxtronoly larso valuo. ‘l'hio io noaninslooo bocauoo of tho hotoro-
sonity of tho colloid oyoton, which oyotoao do not follow tho lawo of co-
nctic prooouro.

Hanoi-(M) boliovoo that tho hydratoo of oilioic acid aro but
arbitrarily ooloctod otatoo in a ccntinucuo oorioo botwoon tho hydrcocl
and tho dohydratod oilioa, and aro roprooontod by pcinto on a conthuouo
dryins curvo.

In hio otudy of colloidal Iotallic oxidco, Sioz roooivod opocial
attontion fro. Van Bo-olonus). Bio invootisationo of tho pwoioal pro-
portioo of oilioa sol includod tho oquilibriu conditiono oniotins botwoon
tho woisht of wator hold por sran of Bioz and tho vapor prooouro. no ootab-
liohod a hydrationodohydration ourvo frm which ho concludod that tho hydro-
sol of oilioic acid io of an unotablo capcoition of tho sonoral cupooi-
ticn “02.11320, tho valuo of g dopondins on tho proviouo hiotory of tho sol.

'rho otruoturo of oilioic acid solo hao boon tho objoot of con-
oidorablo invootisaticn for any yoaro. Prmkonhoin in 1885 boliovod
Jollioo to bo ossrosatoo of onall cryotalo with pen botwoon thou. I. Yon
hasoli in 1879 adoptod a oinilar viow that solo woro caapoood of oolocular
caploxoo or nioollao, with cryotallino proportioo, ooparatod by okino of
£20 and fornins intorotiooo in which B20 was containod by nolocular attrac-
tion. nonunioh‘“) asrooo clcooly with thio viow, ccnoidorins solo to
bo tho oano ao oolo, in which oclid particloo aro oc abundantly prooont,
that tho' dioporoion nodiun, tho liquid, in roducod to vory thin filao,
which, liko a foot. ooparato tho clcooly packod particloo. Van Bollolon
boliovoo that tho colloidal particloo of oilioic acid arranso thonoolvoo

-s-

with tho wator noloculoo to fora a coll-liko otruoturo of dofinito ccnoti-
tuticn, and that thooo collo buns tcsothor at cortain pointo to for: a not-
work. Butcchli hold a oinilar viow to Van Box-colon, but in 1911 thio
thoory wac dicprovod by Zoisncndy who oxaninod with tho ultrooicroccopo

a dry sol which had boon troatod with bonool vapa'o. Lo tho bonaol ovapcr-
atad, tho Tyndall canon") appoarod, and faintly diocorniblo oubnicrono,
which srow in brishtnooo, woro coon. fhooo oubniorono bocano oc brisht
that thoy illuinatod thoir noishborins particloo. Thin lisht wao linoar
polaricod. Bachnann, in lOl'I, found by hio vapor prcocuro iocthorno, that
tho pcroo of oilioic acid solo havo radii botwoon 2.5 and 5 nilliaicrono,
which io about 300 tiooo onallor than Butcohli'o honoyooobo. fhooo oxpori-
nonto' oxplain Yon Bonolon'o hyctorooio cyclo. Zoisncndy and Bachnann
favor a fibrillar otruoturo. chain (1920) holdo a viow oinilar to Pround-
lichue) 'and Patrick"), that idontical colloidal particloo aro prooont in
tho ocl and sol otato, which diffor only in nochanical risidity and olao-
ticity. Bradfordo'a) omriaoo tho difforont hypothooio concornins sol
otruoturo hold by variouc invootisatoro, and claooifioo tho difforont oyotono
undor which solo fall.

. fho tondoncy ozhibitod by all oclido to ccndonoo upon thoir our-
faooo a layor of any sao or liquid with which thoy nay bo in contact io
tornod adoorption. Tho amount of adocrption io ocnditionod prinarily by
tho oxtont of ourfaco oxpcoodus). Sinoo ncot oharccalo oxhibit sroat
ourfaco duo to pcrooity, ccnoidorablo work has boon dono with thio cub-
otanco. In cortain toohnical prooooooo oilioa sol ocapotoo with activatod
charcoal, oo at tho prooont tiao thoro lo a diotinct difforonco d opinim
ac to tho rolativo norito of oach ao on adcorbont.

. Patrick wao anons tho firot to invootisato tho adocrption of
saooo by oilioa 91(6)“). Daniolo and “cont-(3°) propcoo to adoorb

nitric onido with oilioa sol in tho arc prccooo for tho fixation of nitro-
son. rho Royal Dutch Sholl anany of Ban Franciocc, California. hao ouc-
cooofully onployod activatod oilioa sol to ronovo oulphur cupoundo frao

oil and to rooovor saoclino moron”. Gaoolino pnrifiod by oilioa sol

wao found to bo ouch ouporicr to that proparod in tho ordinary nannoruw ,
whon uood at a nctor fuol. ”(28) found that ordinary oilioa 3.1 only
taboo up 23: or ito woisht of bonxono. coho-(3‘) otatoo that ho pro—
ducod a vory activo sol by troatins ocdiun oilicato with niokol chlorido.
rhia sol, ho ropcrto, will adoa'b 1001 or ito woisht of bottom. origami)
proparod a sol by a opooial procooo which at 400’ O had an adoorption
capacity so; sroator for nitroson than tho boot charcoal blown. Silicic
acid solo havo boon ucod ao a vohiclo for natal oatalyoto. Royorocn and
Thaaou‘) proparod a sol by tho Patrick nothcd and aftor dryins owacuatod
it at 250° 0 for two houro. It wac thou troatod with puro hydrcson. Iftor
adocrpticn oquilibriun had boon roachod, ocluticno of oalto of tho notalo
to bo dopcoitod woro addod. Gold, oilvor, platinu, palladiu, nickol,
and ccppor oalto woro uood. 0f thooo, palladim and nichl ohowod rooark-
ablo activity ac a catalyct in tho hydrcson-othylono roaction.

rho procodins briof roviow of tho litoraturo io'nct intondod to
ocror tho ontiro fiold. rho paporo conoidorod woro includod for tho roaoon
that thoy appoarod to havo a diroct boarins on tho proporty of adoorption.
In viow of tho fact that thoro aro oc nany variaticno in tho proparaticn
d' oilioa sol which affoct thio proporty, a nothcd .bracins tho ncot
dooirablo foaturoo of tho nany known nothcdo ohculd rooult in a ouporicr
sol.

i'ho indication of tho furthor poooibilitioo of opooially pro-
parod oilioa solo lod tho writor to tho conoidoraticn of tho offocto of

forric oxido on tho adoorptivo proportioo of oilioa sol. A sol which

-7-

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will horoinaftor bo doocribod wao proparod and ito adoorptivo proportioo
otudiod with an orsanic and an inorsanic sac. Bocauoo of tho fact that
throo chiof factoro influonco tho adoorptivo activity of a sol, thooo
throo factoro will bo conoidorod ooparatoly ac followo:

l. lothcd cf proparaticn;

2. lothcd of purification, or ronoval of by-producto;

3. Iothcd of dryins and activating and, finally, toot of,

4. Adoorptivo capacity of tho solo with carbon totrachlcrido

and anonia saooo.

W11.

1. RIPARATIG 0‘ (BA.

1 oorioo of oilioa solo wao firct proparod containins varyiig
concontratiaio of ocdiu oilicato and hydrochloric acid. Thio acid was
chcoon bocauoo of tho ouo with which alkalino chloridoo diffuoo fro-
solo. Thic wao coco-pliohod by varyins tho opccific sravity of tho ocdii-
oilicato oolution whilc koeping tho quantity of acid uood fixod. Tho
oorioo of solo wao nado with tho viow of chcocins for tho following
orporinontal work a sol which confornod noro noarly from tho phycical
standpoint to tho but solo doocribcd in tho litoraturo. A canorcial
wator slaoo wao uood havins a opocific gravity of 1.3960 and with a

Iago - 810 ratio of l to 4.2. In tho followins analycic nothyl cranso

2
wao uood ac an indicator.

TABLE 1
Gapcoition of Iator Glaoo .
sodiu ouido (lazO).....................7.72%
8111a (8102)..........................cz.42%
loiotm-o...............................69.86$

89001110 gravity........................1.396

Tho nothcd of proparaticn of thooo solo wac oinilar to that
uood by Snitoszn procautiono boins tahon to bo uniform in procoduro.
Tho sol finally ooloctod wao nado frm tho' followins nixturo:

lator slaoc solution (op. sr. l.l)..........4 parts

301(Ip. 5r. 10°57)oooooooooooooooooooooooool part

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Thio nixturo oot to a cloar sol in 6 houro, fron which cynorocio wao con-
ploto in 6 doyo.

A lothod was now dovclopod for ilprosnatins tho sol with col-
lcidal forrio ouido. Sovoral nothcdo woro triod which woro acro or loco
cuccoooful. but ao tho final sol wac unoatiofactory, thooo woro rojoctod
ono by cno. Forric chlorido ocluticn wac addod diroctly to tho wator
slaco. but duo to tho hydrcson ion fra hydrolyoio tho nirturo oot innod-
iatoly into a ccoroo ctroaky sol. Vory diluto forrio chlorido wac addod
with no bottor rocult. Tho puro oilioa solfundriod, wac idorood in a
oclution of forrio chlorido for «moral dayo, and thou boilod to facili-
tato hydrolyoio. Tho sol wao brohon into onallor piocoo which woro oc
brittlo that thoy oaoily crublod. Thio wac ropoatod with tho oolid sol,
coins a oonoontratod oclution of forrio chlorido. Tho inoroion wao
corriod on for oovoral duo. By tho color of tho orcoo ooction of tho
sol, it no coon that tho forrio chlorido oolution had ponotratod tho sol
in a uniforn nannor. Tho sol wao than racvod fron tho oolution and partly
driod without waohins. Tho sol wac thon ocahod in dictillod wator. and
aftor 24 houro tho forrio chlorido woo found to havo cuplotoly diffuood
out. Thio wao ropoatod. allowins tho sol to dry opontanoouoly for oovoral
dayo in an attonpt to duplicato tho nothod of Brissoszs) Tho final sol
bocano oc brittlo that it could not bo handlod roadily without crI-blins,
whilo a whito chalky oruot fornod on tho cutoido.

i forrio onido hydroool wac thou proparod by hydrolycio of tho
chlorido in boilins wator. Thio wao ccolod and than uood to diluto tho
wator slaoo. i cloar, tranoparont nixturo rooultod. Tho hydrochloric
acid wao thon addod with rapid otirrins, and aftor a ohcrt tino a cloar.
roddioh brown sol forlod. Thio wao allowod to dry for throo dayc and than

7‘

placod in diotillod wator. Aftor oookins two wooko in runnins wator,
tho sol wao found to havo chansod color but clishtly, oo thio nothcd of
proparation wac docidod upon.

A oorioo of solo wao proparod, oach nonbor of which ohall bo
dooisnatod ac 0., 01, 02. 03, otc.. and oach containins a ohall variahlo
quantity of iron with tho oxcoption of Co which ocntainc no iron oncopt
a traoo which wac found prooont in tho wator slaoo. It wao found that
by dilutins no part by voluo of wator slaco with throo partc by
volt-o of diotillod wator, a nioturo would bo'cbtainod which had tho
roquirod opocific sravity, nanoly, 1.10. Tho solo woro cbtainod fri-
tho followins Iixturooz-

(co) 'lotor slaoo..............................125 cc.

Diotillod wator..........................376 cc.

Eel (8p. Gr. 1.067)...."................100 cc.
(0;) . Thio sol wac nado in tho followins nannorh

316 cc of diotillod wator wao brousht to boilins. Thou 0.26 cc
of a hishly conoontratod' oolution of forrio chlorido wao addod drop by
drop. A puro rod hydroocl wao obtainod. Thio wac ccolod to rcon tonpor-
aturo and thou addod to 126 cc of tho orisinal wator slaoo with ocnotant
otirrins. Thio nixturo wao than plaood in an ovapcratine dioh and 100 cc
of tho diluto hydrochloric acid addod with viscrouo otirrins acrcoo tho
dioh. Aftor a ohcrt tiao, a roddioh brown sol fox-nod.

Tho root it tho oorioo wao Iado onactly ac doocribod for (01)
with tho oxoopticn that difforont quantitioo of tho conoontratod forrio
chlorido oclution wac addod to tho difforont solo. Duo to tho for-ction
of no). durins hydrolyoio of tho forrio chlorido, oach 5.1 containod a

larsor quantity of thio acid than tho ono bofcro it in tho oorioo. Thio

~11-

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‘ .

had a notiooablo offoct on tho opood of solation. which variod fru 6
houro in tho caoo of (0°) to 20 ooccndo in tho caoo of (on). Tho follow-

ins tablo will prcvo uooful in cmparins tho quantity of forrio chlorido
oclution addod to opood cf solation.

 

 

 

ram 2
W. W
Gol oolution addod Galation
co lcno 6 houro
°1 0.15 cc 5 houro
0: ' 0.25 " 12 amt...
03 ' 0.60 " 6 oinutoo
c. 0.15 ' o ninutoc
°5_ 1.00 " 1 nin. 60 coo.
ca 1.25 " 1 nin. 25 coo.
0., 1.50 " l nin. 10 coo.
°e 1.15 " 1 ninuto
°o 2.00 " 45 ooccndo
c10 3.00 " so ooccndo
011 4.00 ' ao ooccndo

 

Tho abcvc oboorvationo woro nado fron tho tino of ctartins
tho addition of tho acid to tho firot appoaranco of solation. Tho acid
wao addod ao rapidly ao poooiblo, about ton ooccndo boins takon for tho
addition. A atop watch vac uood in all caooo oxcopt (co) and (c1) yum
aro but approximation. Aftor tho firot appoaranco of solation. it pro-
coodod vory rapidly, but a fow ooccndo olapoins until tho nioturo had
cuplotoly cot to a sol. Boo fisuro I.

~12-

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.mmmama 2318 m8 2H one? as; St madcap

n

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0H

NH

 

LflMIFr‘? NI DIIILLHS of) mill.

'3':
5..

2. FOREIGQICI (r 0818.

Tho solo woro allowod to act in tho opon air at rcc tonpor-
aturo for four dayo, durins which tiao oynoroooo wac ovidont. At thio
tiao tho solo ohcwod an avoraso ncicturo ocntont botwoon 45% and 657K.
Thoy woro thon brobon into onall cuboo approxinatcly ono inch on oach
adso. Thooo woro oach placod in a two litor boakor and ccvorod with dio-
tillod wator. Tho wator m chansod oi: tinoo oach day for two wookc,
at tho and of which tino all avidonco of chlorido ion had vaniohod accord-
ins to tooto nado with oilvor nitrato. Tho abovo nothod of waohins wao
found to bo noro officiont than runnins wntor. Tho lattor nothod wac
triad on oovoral solo praviouo to thio tino, uoins a ccnatant lovol ciphon
and drawins tho liquid fra tho bottu of tho containor bolow tho sol. l
nuoh lcnsor poricd was found noooocary for waohins tho sol froo of chlor-
idoo than in tho caoo of docantation, in which caoo ton dayc wac cuf-
ficicnt, thoush four dayo lonsor wao tokcn ac an addod procauticn.
Jordio‘za) found, by cookins . 3.1 of oilioic acid in cold wator, that
tho oodim oalt of tho acid uood and tho oxcooc d' acid diffucod out of
tho sol until noithar wao prooont accordins to. tooto. If tho sol io
furthor wachod in wator at a to-poraturo of 100° C. tho oodiu colt,
frat ovapcraticn dotorninationo, dooo not dininioh. Thio lod hi: to
boliovo that a dofinito oilicato wac fornins with tho ocdiun and dio-

oolvins in tho wator.

3. mm (1' 1mm AID ACTIVATIOI CF wagons.

Aftcr tho solo had boon wachod for two wooko by tho nothcd d‘
dccantation, thoy woro roady for dryins. At thio otaso tho solo had bo-
caao conawhat lishtor in color than crisinally and woro found to havo

owollod conoidorably. Tho noioturo contort avarasod 8023. Cara wao oxor-

-13..

cicod in handlins thooo solo or thoy woro ncro frasilc, duo probably to
tho larso ncicturo contont. Procautiono woro taboo to provont tho larsor
lunpo fru broakins down. Thooo solo woro tbn roady fa- tho firct otaso
of dryins. Ac tho purpoco of tho cxporinontal work wao to produoo an
activo sol, and ac tho valuo of oilioa sol ao an adcorbont ic duo to ito
ancrnouc cpocific ourfaco, all procauticno aro nocoocary to provont in-
Jurins tho dolioato cullular otruoturo of tho sol, which injury would
dininioh tho ourfaco. Any docroaca in ourfaoo would offoct tho sol ac

an adocrbont.

Thooo solo woro now placod in a dryins box built for thio pur-
pooo, which wac 8 foot lots, 18 inchoc wido, and 12 iuchoc doop. Tho
bcttu wuc wand and a doublo thicknooc of chooco cloth ctrotchod tisht-
1y aorocc tho cpcnins. A chooco cloth wao alco otrotchod acrooc tho top
of tho box to hoop out tho sroator part of tho duct. Thoush tho solo woro
novor oxpccod to a toaporaturo hishor than 36° 0, thoy driod vory rapidly.
Ac thoy driod, thoy docroacod in cioo and ooncoquantly bocana doopor in
color. At tho and of throo dayo, thoy had docroacod in voluno about 80$
and at tho and of b dayo about 151. Tho sol which containod no iron
(0°) bohavod a littlo difforontly. Durinswachins it incroaood but littlo
in ciao, did not bocmo frasilo, and finally driod nuch noro clocly, about
covon dayo boins nococoary to dry thio sol. Tho final product wac a cloar,
hard sol which had a slaocy fracturo. It would oacily coratch slacc. Tho
solo containins tho iron driod down to hard,brittlo solo, whcco color
variod fro- lisht anbor to doop, roddioh brown and whoco noioturc con-
tout variod frm 18% to 18$. Thooo solo woro thou roady for activation.

By activation ic noant tho frcoins of tho ourfaco of tho ad-
corbont or .11 natorialo not «can. part of ito otruoturo. Many in-
voctisatorc concidor wator ac port of tho otruoturo of oilioa sol.

~14-

 

-\

Proundlich( 16)

boliovoc that cola and solo aro vary oinilar, tho difforonco
boins in tho quantity of dioporcion nodiu prooont. In tho caoo of oilioa
sol, tho cclid particloc aro coparatod by an adocrbod fill of wator.
Prankonhoin, Von lasoli, Bachnann, Zcisncnday, lchain, and many cthorc
favor thio viow. Zcisaondyug) by ultronicrcccopic incpcction found that
tho lowor tho conoontraticn of ccdim oilicato uood in tho sol proparo-
tion, tho onallor woro tho particloc. Patrick“) found durins hio oxpcr-
iaouto with oilioa sol and culphur dioxido that thoro wac a lcwor linit

of ncioturo contont boycnd which docrcaoo in activity occurrod. Ruthsw)
workins with a Patrick sol, found a docroaoo in activity of thooo solo
which woro activatod abovo 250° 0. For tho abovo roaccno it wac docidod
to linit tho final tolpcroturo of activation to 250° 0.

Tho apparatuc uood for thio work io chown in fisuro 2. Tho sol
to bo activatod wac placod in a larso o tubo _o_, which wac in turn placod
in an old rapo cood oil bath 2. Tho frooh rapo cood oil wac proviouoly
hoatod for 24 houro noar ito boilins point to drivo off inpuritioc. Dur-
ins thio prccooo it bocano dark brown and viccouo. Upon ooclins and ro-
hoatins, it incroaocd in tonporaturo uniformly with no apparont vaporiza-
tion. Rubbor ctcpporc woro fittod into tho U tubo and throush thooo air
wao adnittod by noanc of a hard slaco load-in tuba. Thio wac inoulatod
with aobootoo. Tho 'T" wac oquippod with a thornaotor woll 3. Tho slaco
load-in tubo and 'T" woro coalod tosothor by tishtly windins aobootoo cord
aorcoc tho junction. A coalins cmpcund of slycorino and litharso wao
pourod cvor thio cord, and than hoatod with a cocky flano. A partial
rodacticn of tho litharso by tho slycorino occurrod, and a hard, sray-
cclcrod coal wac obtainod. This could bo oaoily brobcn by pcurins hot

wator cvor tho coal. Tho slaco "T" wao ccnncctod to an iron tuba 3.

~16-

f.

 

14

which wac fillod with chinslc nailc which actod ac an air bafflo. Thio
tuba wac hoatod by sac. Ocnnoctod to thio tuba on tho oppccito and wao a
U tubo s fillod with dohydratod Caclz, and to thio wao connoctod a bubblins
colun fillod with concoutratod 0.P. 3230“ Air wac drawn thrcush tho
ayatan by a cucticn pup connoctod to a cafoty trap P. by tuba g. Thio trap
wao placod in tho oycton ac a procaution asainct back procouro ohould anyf-
thins so wrons with tho auction pup. Aftor tho sol to bo activatod wao
placod inUtubcg, tho tcnporaturowac broushtuptc 86°0bynoano d
a burnor placod under 9.. Air wao drawn thrcush tho cyctan cinultanocucly
at tho caoo tocporaturo ac tho oil bath. Tho tonporaturo wac hapt botwoon
00° 0 and 90° C for oi: houro. Durins thio tiIo wator vapor wao coon to
condcnco in b. Tho tonporaturo wac than raicod to 260° 0 and bopt at thio
point for two houro. Tho ctcp cccko woro than clocod, thuo icclatins tho
U tuba and contontc, than tho cyctan wao allowod to cool. Aftor ccclins,
tho sol wao placod in an orlonnoyor flack which wac thon coalod with
collcdicn. Bach sol wao activotod in tho nannor juot dcocribod. Tho
volmo of air por nimto drawn thrcush by auction wao hopt conctant by
'ccuntins tho bubbloc par ninuto which paoood thrcush tho 3280‘ colt-n h.

Aftcr activation, tho solo woro found to havo chansod thoir
appoaranoo fra a chiny, roddioh brown to a dull, rod purplo.

Tho noioturc and iron ccntout of oach sol wao now dotorninod.
Bach sol wac pulvoriood by uco of an asato nortar until it pacood thrcush
a 40 oach oiovo. mo sran oanploc woro uood for noioturo dotorninaticno.
Thooo woro placod in a platiutl cruciblc and hoatod fa' uactly two ninutoo
ono inch abovo a nokor flonc. Thio lonsth of tiao wac found to bo ouffi-
ciont to ranoro all ncioturo. Tho solo woro found to chansc fra a purplc-
brown color to puro whito durins hoatins. Upon coclins a faint sroonioh
tinsa wao ovidont in tho sol.

~16-

Tho iron contont of oach sol wao dotorninod by tho nothcd of
zinnornann and Roinhardt, with tho oucoption that tho oilioa wac firot
rcncvod ca 894 by noanc cf hydrofluoric acid. Tablo 5 ohowc tho ncio-
turo contont, and iron contont ao p.203.

TABLE 3.

 

 

 

Grano i 5 par Eran Fog par
of Gal

Gal Gran Gran of o1
00 .0421 Traco
01 .0647 .0025
Cg .0755 .0048
03 .0717 .0059
04 .0662 .0071
05 .0542 .0087
as .0489 .0097
07 .0531 I .0106
03 .0566 .0118
09 .0650 .0128
C10 .0721 .0178
On .0854 .0225

 

Tho abncraally hish ncioturc contcut of 011 may bo accountod
for by tho wator of hydration hold by tho hao; which ic additivo with
tho wator of otruoturo of tho sol. Thio io undoubtodly tho caoo with
oach sol with tho oxcoption of 0., which hao tho loooct ncioturo contont
of tho oorioo.

4. msmruoo IITE OARBCI TETRACHLQIDE.

Adcorption hao boon dofinod as a lcccc fixation of a oubctanco
at an intorfaco.(16) Thio nay bo pcoitivo or nosativo, thoush tho lattor
io ucually cc anall ac to bo uuoaourablo. Adcorption ia tho rcoult of a
difforontial anictins botwoon tho rato of condonoation and ovaporation at
an intorfacoiu) Thioic duo ontiroly to intonoity of ourfaco forcoc.
Accordins to Lansnuir, thoro aro two diotinct claococ of adccrption, nano-
1y, chonical and phycicalsu) 8y ohanical adccrption io noant tho typo
oxhibitod by activo adccrbontc ouch ac notch, and by phyoical that chown
by inort adccrbontc ouch ac nioa, oilioa, and charcoal. n. furthor difé-
forontiatoc botwoon tho two typac of adccrption ac prinary and cocondary,
prinary adccrption boins duo to primary valonco forcoc whilo cocondary
adccrption ic doc to coccndary valonco forcoc. It follcwc tint tho lattor
io tho woakor. of tho twc- forcoo conoidorod. Bonton‘sz) claocifioc thooo
two typoo accordins to tocporaturo and proccuro offocto, chcwins that
cocondary adccrption docroaooo rapidly and continuouoly with incroacins
tonpcraturo, but incroacoc sradually with incroaoins proccurc. Pricary
adccrption, on tho othor hand, firot inoroacoc and than docroacoo with
incroacins tonporaturo, but incroacoc vary rapidly with incroacins procouro.

Bay( 23) ccncludoo froo hio rocoarchoo that an adccrbant hao a
sroator adoorptivo capacity for thooo ccnpcundo which fall in tho caoo
clacc with roopoct tc thair orisin, i.o., orsanic or inorsanic, and will
proforont ial 1y adcatb thooo capoundc , aftcrwardc oxhibitins sroat roton-
tiv ity whon hoatod and ovacuatod.

Tho adoorptivo capacitioo of thio oorioo of solo wac dotorninod
dynamically. Dry air oaturatcd with 0014 wao paoood ovor a woishod canplo

of tho sol until no furthor incroaoo in woisht wao cbcorvod.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

.n chum.“ .m

 

 

 

 

 

\\\\\\\\\\\\\\\\\\\ \\\\\\\\\\\\\\
v \
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\

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Tho adccrption train uood for thio purpocc ic chown in fisuro
3. Air wac pinpod into chanbor Ewhich waa hopt at rcou tcnporaturc.
Thio chamber prcvidod a noanc for trappins any oil which nisht paco oror
fron tho blowor, and likowico to connect tho cyctan to a cafoty coluan
3 thrcush tuba g. Thio cafoty column conoiotod cinply of a tubo dippins
into a norcury colmn. Tho column could bo raicod or loworcd at will,
thuc incroaoins or docroacins tho hoisht of tho column of norcury. In
thio nannor any dooirod proociro could bo cbtainod, tho oxcooo of which
would bo roliovod thrcush tho cafcty ccluun. Tho air paccod thrcush _o_
into a bubblins ccluan _f; which can fillod about two-thirdc full of con-
contratod 0.P. 2280 . Thio coluan corvod both ac an air dryor and a com
for chockins tho nannor in which tho pup wac functionins. Any lock in
tho cyct- boycnd thio point could bo dctoctcd by tho ratc at which tho
air bubblod thrcush tho coltnn. Prat tho coluan f tho air paocod to a
larso U tuba which wac fillod with dohydratod Gaclz. Thio corvod ac an
additional dryor and likowico ac a cpraytrap fron g. In oorioo with
thio U tuba wac a onallor U tuba h fillod with slaco wool which ccroonod
out any duct particloo which night bo carriod fra s. A throo way ctcp-
ccck _i_ wao placod in tho oyctan at thio point for oafoty purpcooc ohould
tho blcwor fail to function prcporly. A noroury baruotor 1 wac uood to
noacurc tho proccuro in tho oycton boforo tho air paocod thrcush tho capil-
lary _1_ of tho flownctor 5. Tron tho flownotor tho air paocod to throo
flaokc 3 fillod with 001‘. Thooo alcc containod slaco wool which corvod
ao a bafflo for tho air. A fourth flack g wao fillod with slaco wool to
catch any opray which nisht paco frm tho 001‘. Thooo flaoko woro placod
in a larso roctansular slaco battory jar _c_ which wac in turn placod in a
hoavy cardboard containor p. Sawduot wac tishtly pachod around tho slaco
Jar to inoulato it fron tho row. Ico wac pachod around tho caturcticn

train in tho slaco Jar, and tho train ccvorod. Tho air paocod frm tho
caturation train into a U tuba 5. which containod a known woisht of activat-
od sol. Tho I] tuba wac placod in a conctant tanporaturo lobar oloctric
furnaco _._ and tho tanporaturo rosulatod to 35° 5. Tuba _t_ ccntainod nzso,
thrcush which tho air wao diocharsod. Thio actod both ac a coal and a
noanc for dotoctins any lock in tho cycton botwoon atop-cock _i and tuba
g. Tho adccrption wac carriod on ac followo:

Each sol wac sround in an asato ccrtar until it paocod thrcush
a forty nooh oiovo. It wac found in oach caoo that 23% to 261 of tho
total sol would not pacc throqh a cixty oach oiovo. 10% to 12% would
not pacc thrcush an oishty noch ciovo, 207‘ to 25$ would not paac thrcush
a cno hundrod oach oiovo. Tho ronaindor paocod a ono hundrod oach oiovo.

A canplo of tho sol wac placod in U tuba _i; which had proviouo-
1y boon woishod. Tho tuba and sol wac rcwoishod and th.: placod in tho
furnacc and connoctcd in oorioo with tho train. Tho sol wao allowod
to otay in tho furnaco for 30 ninutoo to arrivo at tho cno tonporaturo
ac tho furnaco. Tho atop-cock 3 wao now cponod to tho air and tho blowcr
otartod. Tho proocuro wac adjuctod until a difforontial of 5} continotorc
wac cbtainod aorooc tho flownotor. Safoty column 3 wao than adJuctod
until air juot otartod to bubblo thrcush tho coluan. Tho proocuro wac
than roadjuctod until a difforontial of 5 continotorc wao oboorvod acrcoc
tho flownotor. Tho atop-cocko of U tubo 5 woro than cponod, and finally
atop-cock 3 woo clccod to tho air and cponod to tho cyatan. At intorvalc
of 15 cinutoo tho sol wac rcwoishod until a conctant woisht wao cbtainod
ovcr coo-half hour. At tho abovc proocuro difforontial 100 cc. of sao
por ninuto paocod thrcush tho sol.

Tho adccrption capacity of tho difforont solo toward an; wno
now tootod. Tho sao wao paoaod dircctly thrcush tho flownotor into tho

woishod sol which had provicucly roachod tho tonporaturo of tho furnacO.
A proocuro difforontial of 5 a. wao uood ac boforo. Tabla 4 chowo tho

rocultc of tho adccrption tooto.

 

 

 

 

TABLE 4

“ m, .11.. Matti. *m‘d'?

Gol # par sron of sol por sran of sol _A sranc 0014*
0. .0454 .0381 .0875
01 .0299 .0255 .0945
02 .0205 .0204 .0959
03 .0291 .0300 .1014
c, .0375 .0359 .1038
05 .0488 .0440 .1020
0'8 .0509 .0385 .0998
01 .0458 .0330 .0999
08 .0402 .0305 .0953
G9 .0381 .0250 .1031
010 .0219 .0232 .1000
011 .0238 .0215 .1102

 

Tho curvoo ohown in fisuro 4 furniah a noano for caparins tho
woisht of 0014 adccrbod by ono sran of tho difforont solo durins cqual
intorvalc of tho at 35° 0. Thoy tabo tho fora of caturation curroc, and

chow tho adccrption ratc of tho varicuc solo.

DISCUSS 1r:

Ira Pisuro 1 and Tabla 2 it ic coon that tho rclativo tino of
solation for tho difforont solo varioc with tho quantity of forrio chlor-
ido addod. Pcrrio chlorido in contact with boilins wator hydrolyccc
vory rapidly, furniohins 501 and forrio hydroxido accordins to tho follow-
ins oquaticn:

Pocls a 3 H20 .- nun), «- 3 H01
It ic boliovod that "(01); oxicto ac a hydratod oxido Fo203.3320, thoush
lillisan(33) clainc that no dofinito hydratod ocido of iron orictc.

It io coon that tho opood of solation chansoc oncrncucly bo-
twoon solo 0° and 011' Thio ic curpricins whon tho rolatiroly caall in-
oroaoc of hydroson ion ovcr tho orisinal hydroson ion ooncontraticn io
conoidorod.

Tho incroacod opood of solation of tho solo with inoroaco in
forrio chlorido ic of intorcot. Followins ic tho incroaco of opood of
solation ovor tho prcvicuo cnc in tho oorioo, with tho cocondins oorioo
of forrio chlorido concantratticn:

c. - 1, 01 - 1.33, 02 - 25, 03 - 2.4, c, - 1.1, 05 - 1.54, 05 - 1.3,
07 . 1.21, ca - 1.11, 09 - 1.33, 010 - 1.51, on - 1.51.
Tho total incroaco in solation opood fra 0° to 011 ic 1080 tinoo.

Pisuro 4 ic a sraphic roprooontaticn of tho rolativo opood of
adccrption of tho difforont solo at a dofinito tonporaturo. Thooo aro
typical caturation curvoc. Tho followins tabla indicatoc tho incroaca
in woisht of tho solo duo to adccrption of tho 0014 at dofinito intorvalc
of tino.

10

 

 

 

'7

 

 

 

 

 

 

 

 

 

 

 

L—-—--—f
r—i

 

 

 

 

 

,

 

 

 

//

 

A

/

 

 

 

 

 

 

 

 

rj/

MI

 

 

 

 

 

 

 

 

 

.05

.05

4.
0
O

//[/

2
0
c

 

:5 8 3:6 «an unnamed «So .8 mass

 

.01

 

 

2 houro.

1 hour a

 

TIME IN HOJRS .

(Tonp. 35° C.)

Figure 4.

TABLE 5

 

LTotaT .11.. per

 

 

Gel l5 nin. 15 nin. k hr. i hr. t hr. sron of sol
0., ‘ .0380 .0030 .0019 .0005 0000 .0454
01 .0255 .0025 .0015 .0004 0000 .0299
02 .0130 .0034 mm .0022 0000 .0208
03 .0200 .0033 .0035 . .0001 0000 .0291
c, .0310 .0040 .0030 .0003 0000 .0313
05 .0404 .0051 .0021 .0003 0000 .0488
05 .0410 .0034 .0003 , .0002 0000 .0309
01 .0330 .0030 .0020 .0008 0000 .0433
ca .0340 .0040 .0022 ----- 0000 .0402
09 .0320 .0040 .0013 .0005 0000 .0381
010 .0220 .0044 .0011 .0004 ' 0000 .0219
on .0190 .0031 .0005 .002 0000 .0233

 

It io of interact to note that on tho averaso tho solo adccrb
appronilately 81% of tho total enount in tho firot 15 ninutec.

Specific adccrption of .the different solo with 001‘ and In;
wao plotted. Thece are chcon in fisuro 5. The solo are reprecented
on the abcicca by their 11.203 concentraticnc. With °°14 it wao found
with the accendius concentrationc of 2.203 the curve reached a lini-
nu for 02 (coo table 3). With incrcaoins 15203 concentration opocific
adccrption increaoed until sol °5 wao roachod, and than clcwly docroac-
ed to the end of the oorioo. The on; curve ic very cicilar with the
exception that maxim cpocific adccrption oecurc with sol 05. The

ccicture content of the solo with the aocendins ”203 ccneoutrationo

~23-

1“

.w—..F-

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fl
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l
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7‘
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w
I ' V
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l

 

.m Emu:

 

.86 8 name and coach .6 mass

GRAMS OF H

,0 PER can; cr- GEL.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

one. «No. ONO. 20. 30. 30. 20. 0.8. woo. woo. 30. N00. 0
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' NOIMHOSGV 01.510st .

wao alcc plotted on the cane sraph with the cane ocale. It io coon that
the water content reacheo a maxim for sol 02 and a niniann for sol 05.
Gel 0° likowice appearc ac a niniuun. Ac the 2.203 concentrationo increace
froo 05, tho-noicture content sradually increacoo. Ihen the 0014 and noio-
ture curvoc are oboorved tosothor, a narkod relationohip ic readily oboorv-
ed. Tho nciottn'o curve appoaro to be a nirror inase of the 001‘ curve,
i.o., a nininun exhibited by the 0014 ccrrecpcndo to a noxiou- on the
ncioturo curve. Where the clcpe of the 001‘ curve ic pcoitivo, tb clcpe
of the noieturc curve ic nosative, and vice verca.

From the cancer of. behavior of cilica sol ten hoatod, it appoarc
that the view of Treundliohu”, Patrick(°)(7)(°), and cthero resardins the
otruoturo io correct. It io probable that the particloo which ache up
the sol are of the cane oioe ac thcce whieh'naha up the col. In the caoo
of solation, the ccntinucuo phaco hao docroacod sroatly in vclue and the
colloidal particloo are core clccely packed. Slow dryins allowo thooo
particloo to pack thenoolvoc in a nor-a1 nannor with a naxicun nunber cf
pcreo of unifor- oioe. The colloid particloo (3102) are currounded by
a fill of water which allowo linited notion to the nacc. Thio fill of
water, which ccnctitutec the ccntinuouo phaoo, precervoo the sol otruo-
ture and ccnoequantly precervoo the umber and cioo of pcreo. The nunber
of pcreo undoubtedly dooo not choose durins prelininary dryins and activa-
tion, thoush it ic very probable that their cice dooo chanso. Al the
‘ noioture eccapec, tho particloo cattle tosothor, thuc decreacins the
voluwo of the inter-opaco and ccncequently the pore oioe. Thooo inter-
opacec between particleo conotituto tho pcreo. After activation, it io
believed that the reaainins water io adccrbod «1 the particloo. If thio

ic renoved by haatins, the ncicturo io replaced by air bubbleo which sivo

-24-

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a chalky appearance to the sol. Upon ctill further hoatius, thoce air
bubbloc dioappoar and the porn becone unifcrnly 2111.3 with air. The

sol then becuec slacoy, trancparent asain. Any rouainins water ic ctrcns-
1y adccrbod and the sol irreverciblo and inactive at thio point. It wac
believed that if it were pcocible to uniforlly fill thooo pcreo with col-
lcidal particloo of very coall dinoncicn, ouch ac p.203, the ninber of pcreo
would be increaeed and a ctill sroater curfaco would be procented. Tcsether
with thio it wae boliovod that 1.20, would exhibit a powerful adccrption
for saoec which would penetrate into the pcreo.

It will be recalled that durins activation of thooo solo a
chanse in color fron roddioh brown to purplich wac oboorved ac the Icic-
ture content docroacod. When furthor heated -- durins acicture content
deterninaticno -- the solo becace pure white. Upon occlins, a yellcwich
sreon tint wac oboorved, which no due to the iron prooont, probably ac a
nixturo of ferrcuc and ferric cilicate. Upon addition of water no chansc
took place, which chncd the chanse to be irrovercible. The chense fru
red-brown to purple-brown durins activation wao undoubtedly. due to a chanse
of water of hydration, a different hydrate boins for-ed.

Due to the incroacins Pe203 cutout of the sol oorioo, they were
expected to chow brittleneco after activation in direct proportion to their
iron concontration. Thio wac expected on tho bacic of the outcone of fella
and Pirth'cu‘” rocoarchoo. Thio brittlenccc did not caterialioe, howcvor.
The fact that the solo were hishly colored after activation wac cufficient
to indicate the colloidal natwe of the 15203 prooont, at loact to acne
extent. Undoubtedly .ca. asslaeraticn had taboo p1... durins the 5.1
contraction, which nay have recultod in the fornation of a different hydrate ,
thuc chansins the color of the sol.

-25~

 

..‘

’1

Pron fisuro 5 it ic coon that mimic adccrption occuro at
nininun ncicture content, and nininun adccrption at mini. ncicturo con-
tent. If the woisht of water per sran of sol be added to the woisht of

CGI‘ adccrbod per sran of sol (coo table 4), it io coon that the once are
nearly conctant. The avercsc cf thece cunc ic practically identical with
the can obtained fro. ,°6’ Thio leadc to the opinion that the iron con-
tent had nothins whatecor to do with the activity of the sol. The noio-
ture content dooo, havever. Thio my be explained by aoaunins a carica-
adccrption capacity of the orisinal oilioa sol (0.). By varyins the
water content of. water by hydration of T5203, and water of otruoturo,
”part of the adccrption capacity wac oaticfied. Upon addition of 001,

the renainins capacity wac caticfied, and the cerioc of solo exhibit vary-
ins dcsreec of adoorptivo capacity due entirely to the difference in Icic-
ture content.

The In: curve io very cinilar to the 001‘ curve, thoush fru the
rocoarchoo of Patrick and Davidhoicer“) it woo expected that tho adoorp—
tivo capacity of the sol would vary directly with the ncicture content.
1h. recultc do not chow thio, however, which ic an indication that th.

total water prooont ic not free to take up the was.

.'26-

GUCLUBICIS

l. Colloidal hydrated ferric oxide was highly protected by the
ecdiu eilicate when the acid wae added. This wae evidenced by the char-
acterietic red color of the gel after eetting. Upon waehing thie gel,
the color remained.

2. During activation, the red-brain color of the gel changed
to red-purple. Thie wae due to loee of water of hydration of “the ferric
aside, a different hydrated oxide being found.

3. The epecific adccrption curvee for both 0014 end In: ehowed
uni-an adccrption with nininnn ncietnre content, and ninienn adccrption
with minn- noieture content. The adeorptive capacitiee cf the gele
therefore vary invereely with their noietnre content.

4. The epecific adccrption cnrvee ehow nail-a and ninina regard-
leee of the iron concentration of the gel. The iron content therefore
has no effect on the adeorptive capacity of the gel.

5. The etrnctural water of the gel and the total water are not
the cane, nor do they exhibit the cane effecte on adsorption. This in
chain by the behavior of In; with Go in contract with the reet of the
eeriee. According to Patrick and Devidheieer, the adeorptive capacity
for ma ehould vary directly with noieturc content. Thio ie not true ft:-
the eeriee of gele need in theee experinente.

d. The water held by the Fezos ie water of hydration and doee

not give the cane effect ac the water of etructnrc of the gele.

-27~

BIBLICBRAPHI

1. 11. Watts: Dictionary of Chemistry, 3rd Edt. (1888).
2. Patrick: Chicago fleeting Am. Chem. Boo. (1920).

8. 5.1-»: J. Phy. Chen. _2_2_. (1818). '

4. 1'. Graham: Phil. Trane., (London) _1__5_1, (1881).

8. Ind. Eng. Chen. 11 (1828).

6. J. 1:. Chen. 8... 32 (1820).

7. J. 1:. ch“. Soc. 38 (1821).

8. J. in. Chem. Soc. 33 (1822).

8. J. 1.. Chen. Soc. 3; (1818).

10. Graham: J. Chen. Soc. _1_§ (1882).

11. c. Roberts: J. 1:. Chen. 800. g; (1888).

12. 1'. Oarnelley and J. 11.11:»: J. 1.. Chen. a... _5_3_ (1888).
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14. J. I. Keller: A Oapreheneive Treatise on Inorganic and Theoretical
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16. Van Benelen: Zanorg. Chen. _l_3_ (l896).
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17. J. Tyndall. Proc. Roy. Soc. _l_‘_!_ (1869); Phil. lag. g: (1869); Proc.
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18. lature (1828); Biochemical Journal (1828).

18. Getlan: 088118.. of Phyllonl Chenietry, 3rd Bdt. (1822).

20. Ind. Eng. Chem. 15 (1828).

21. Turn. 1.. 11m. Chen. Eng. (1828); 8111.. 6.1 Corp., 8111. _4_ (1828).
22. Bur. llinee Serial 2617 (1923).

28. Chen. not. Eng. 32. (1828).

-28-

I O O I
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24. low Haven fleeting An. Chen. Soc. (1923).

26. Proc. Royal Soc. _1_o_o_11 (18281).

26. Colloid Bynpoeinn Monograph, Uinneeotn Meeting, 3 (1926).
27. B. 1.. 81118.: Ph. D. Theeie, 111411115... State 00110;. (1828).
28. z. llectrochen. 11 (1906).

29. Zeigncndy: Chenietry of Colloide, Speare Edition.

30. B. L. Ruth: ll. 8. Theeia, Iichigan state College (1926).
81. Langmuir: J. Ann. Chen. soc. _82 (1818).

32. Benton: J. An. chem. Soc. _4_6_ (1923).

88. 111111;»: J. Phy. Chen. 3;; (1822).

32. p.11. and Firth: J. Phys. Chen. 3! (1926).