1026
W. H. SLABAUGH
VOI. 60
HEATS OF IMMEI1SION OF SOME CLAY SYSTEMS I N AQUEOUS MEDIA BY W. H. SLABAUGH Deparheut of Chemistry, Oregon Slate College, Coivallis, Oregon Received April 4, 2966
Hc:Lt,s of iininersion are given for raw. centrifuged, and sodium imd calcium 1)cntonite in wtter, butylamine, hitylainine liydrochloride and allcyldiinethylbenzylammoniuin chloride solutions for the purpose of seeking data that permit the development of a reaction mechanism. The data indicate that them is a definite difference between the reaction of a n amine mid an aniine hydrochloride with a clay system. calorimeter. During a single dcterminat,ion the temperatfure of the cdorimeter is rated about 0.005'. This small change does not appreciably affect the standardization of the instrument. The sample tube, contnining 0.2000 g. of material, is made of 7 mm. i.d. Pvrex tubing 55 mm. in length. The samoles are outgassed i t 52" and-0.01 mm. pre&ure for 24 h o b s . The tube is broken by a rod which is forced against the tube by an external screw. The correction for the heat of breaking the tube is attributed to the heat of wetting of the inside surfaces of the glass tube, the kinetic energy of the aqueous medium which rushes into the tube upon breaking and the heat of wetting of a cotton plug which is needed t o prevent, loss of sample during outgaming. The tube breaking correction, applied to all measurements, is 0.23 cal., 0.03 cal. of which is attrihutJed to the kinetic energy of entry of aqueous media into the tube. The results, espressed in calories, are based upon the relationship: 1 cal. = 4.186 joules. Measurements in this study were made on Wyoming bentoiiite which wa8 treated prior to the heat of immersion observations in the following manner: Raw bentonite: 200 mesh clay, as received in a sample supplied by tjhe Baroid Division, National Lead Company. Base exchange capacity is 82 meq./100 g. Raw centrifuged bentonite: clay containing less than 0.1% quart>zwhose base exchange capacity is 92 meq./100 g. of clay. In bot,h samples of raw bentonites, only 5070 passed tlit,ough a 200-mesh sieve, 1 0 0 ~ passing o through a 100-mePh sieve. Sodium Iicntonitmewas prepared from the raw centrifuged I)entonit>eby passing a 1.5yo suspension of it through an Amberlite IR 120 column charged with sodium ion. Calcium bentonite was similarly prepared in a column charged v i t h calcium ion. These clays were recovered from the aqueous media by either removing the water in a 105" oven Thc calorimeter used in this study cousists of a wide- (herenfkr called an ovendrietl c1ay)followed by grinding with inout,h pint Dcwxr flask containing a 38.1 1 ohm stitndardiz- it moi,t,ar and pestle to 200 mesh, or by a freeze-drying tig heatiiig coil, a sample tube holder w i t h a screw-type method described by Ca11.6 These clays are believed to be br ,&Icing device, a thermistor,4 and it stirrer, driven by a converted t'o homoionic systems that are a t least 98% pure 110 r . p . m . The flnsk, clamped c.onstant speed motor a t in tthe specified ion. All clays were oven-dried one hour at b y means of a Lucit#ecollar to a plitte of similar material 05' prior t o weighing into the sample tubes. A so-called rind sealed by a rubber gasket, is immersed in a 10-gallon hydrogen bent.onite was prepared in a similar fashion, t:tnk of water, the whole of which, eucept for the extensions using an acid-charged resin column. to the stirrer nut1 tube breaker, is housed in a constant) temSolutions of butylamine and butylamine hydrochloFide perature air-bath. The nii,-bath is t,hermostated a t 30.0 =k \vei'e prepared from Eastman Kodak Company butylamine, 0.1". This holds the watei,-batli at 28.000 it 0.005" and t,he salt being made by neutralizing the amine with HC1 to pt,ovides an environment wherein the internal part of t)he p H 5.00. A 0.1 solution of B.T.C. (alkyldiniethylbenc:hrimeter undcrgoes no more than a constant drift of zylnminoniuin chloride, Onyx Oil and Chemical Co., wherc 0.0001" per minute during an observation. the alkyl radical is principally CI2H,,)was prepared. Freshly The cliaiige in t,enipei'nture produced b y t>lie immersion dist,illetl water \vas used in all cases. of n smiple ifi measured hy the deflection on a one tneter .4nother sei,ies of measurements \vas made in which 0.2 scnlc of a 1,ectls ant1 Kart 1 i w p Type HS g:dvnnoniet~et~ rvliicli J I solutiolis of hut,ylnniine and tiutyl>tmine hytlrochlorid(: indicates thc off-l)nl:tnce of :L Lcetls and ATorthi,upType G-2 w c ~ ac!tlctl , to 200 nil. of :I 1% raw rantrifugcrl hcnt,onit'e \lricller wsistnnce hl,itlgr. The wnsit,ivity of tmhisdetector suspriision. Ihcitusc the concentrntions of t.hc vai,ious bystein I)ermits tht. obspi.v:itioti of teinper:rturc changes of oomponrnts of these i,e:tctioti sysklns \\'ere not, strictly com0.00002". A n obsrrvntion is ni:icle by fiwt providing conparable to the concentrat,ions involved in the immersion of ditions that, protliwe :& const:mt drift of less t,lian 0.0001" p ~ r the dry c,lny saniples, only qualitative comparisons between ininrite. Aftel, 5 minutes of cotist,nnt tli,ift t h e heat cnpnrity these two kinds of determinations can be made. of the sysktn is evaluated by menns of the standardizing heater. \\'ith total contents of t h e cnlorinieter weighed to Experimental Results and Discussion 1 0 . 1 g., the respoiise of the cletectoi, pi,ocluces a scale dcThe heats of immersion of the various cli~ySYSflection of 2 . i 1 f 0.02 cni. ~ P I ' ( d o t i e of hent released in the
Introduction Tlie present study was made for the purpose of providing more information conceriiiiig the interactions among clay surfaces, water, amines and amine salts. In reacting with the reagents the clay acts in a twofold capacity-these reagents may react with the clay surfaces through hydration and adsorption, or these reagents may react with the base exchangeable ions 011 the clay. Because of the low level of energy involved in either of these processes, a detector of high sensiti1-ity is required in studying the heats of these interactions. For this study n calorimeter was designed using a thermistor whose temperature coefficient of resistance TVRS measured in a manner similar t o that of Zettlemoyer aiid eo-workers. The work by Jordan2has shown that amine salts reset with the base exchange ion of the clay, with t>he resulting attachment of the amine ion a t the t m e exchange site. More recent work by the author3 has shown that the reaction of amiiie salts with sodium bentonit,e is accompanied by ail equi\xleiit replacement of sodium ioii from tjhe clay micelle. The present work is m i :tttjempt8t80 gaiii a more complet'e iiii[lerst,:Lii(liii~of these r e : n tioils. Method and Materials
tems were determined, the results being espressed in Table I. Standard deviations are given for eiich syst8enion each of which at least three dete1.miiiatioiis were macle. These clevintioils reflect the tot,:Ll i t c m r : ~ c j rof the tletermiuatious, which involves ( 2 ) 1'. Call. M n l u ~ c 172, , 120 (1983).
THEHEATSOF
Oct., 1955
IMMERSION OF CLAY SYSTEMS IN A Q U U O U S h.IEOl.4
TABLE I HEATSO B IMMERSION OF CLAYS IN VARIOUSMEDIAAT 28.0" 0.1 M
Sample
Raw bedonite (50% 200 mesh) Centrifuged bentonite (oven-dried) (50% 200 ruesld Centrifuged bentonite (freeze-dried) Sodium bentonite (oven-dried) (200 mesh) Sodium bentonite (freeze-dried) Calcium bentonite (oven-dried) (200 mesh) Hydrogen bentonite (oven-dried) (200 mesh)
Water
C~HBNH~
(CAL.
rm
G . CLAY) 0 . 1 icr
CaHsNHz*HCI
I). I ,I1 B.T.C.
....
9.99 f 0.05
11.G8f0.04
11.33 1 0 . 0 4
12.8810.02
14.51f0.05
12.Ci2=l=O0.05
11.56 f 0.05
....
....
....
14.29 f 0 . 0 2
15.16hO.03
14.3ti h 0 . 0 t i
19.57 I!= 0.04
12.0410.04
....
....
....
21.2810.0G
21.U f 0 . 0 5
20.06=kOO.lU
24.13 f 0 . I O
21.02k0.05
25.85f0.01
20.G7f0.10
lS.Y4i0.05
....
the effect of various reagents upon the he:tts of immersion of these materials. An examination of the data. for the heats of itnmersion listed in Tables I and I1 permits the follon.ing deductions: (1) The heats of immersion increase from I X \ V clay to Na-clay to H-clay t o Ca-clay. (2) The removal of the noii-clay fraction from TABLE I1 raw clay gives a clay that has a higher heat, of imH E A T S OF REACTION O F C L A Y S W I T H AMINEREAGENTS mersion. (3) A freeze-dried clay sl10~7sa heat of immersion (CAL. PER G . CLAY) 0.1 M 0.1 ,l!l 0.1 Ai in water which is 2 to 3 cal. less than for an ovenSamplen C ~ H B N HCIHBNHYHCI ~ B.T.C. dried clay. Centrifuged bentonite 1.63 -0.26 5.06 (4) More heat is evolved by immersing a cl:iy ill Sodium bentonite 0.87 0.07 5.28 butylamine than in butylamine hydrochloride. Calciuni bentonite 0.08 -1.22 3.85 This difference is most notahle with the H-clay. Hydrogen bentonite 3.82 0.24 ... (5) The mechanisms of the reactions of the clay with an amine and with ail amine hydrochloritie are a All samples were oven-dried. considerably different. Table I11 gi\res the heats of renctioii betweell (6) The immersion of a clay in a high molecultw amine reagents and R 1% hentoiiite suspeiisioii. \\.eight amine salt evolves a large quantit,y of lieat'. The calorimeter is designed so that the reagent may A brief consideration of these deductions follows. be added in stepwise fashion in nil. portions. The differences in the heats of immersion of tjhese clay systems are attributed to a t least two factors: TABLE I11 the wetting of the clay surfaces aiid the hydration HEATSO F I N T E R A C T I O N BETWEENA m N E REAGEKTS AND of the ion in the base-exchange position. In a raiv 200 ML. OF 1% RAWCENTRIFUGED BENTONITE SUSPENSIONS clay, which contains similar amounts of sodium, Total Total calcium and magnesium ions, along with lay011011vol. of heat evolved reagent 1)er tnrnole of clay impurities (quartz, cristobalite and feldspar), added, reagent added, there is less heat evolved because there is less clay Reagent ml. Gal. mineral, more lion-clay material than in the aentri0 . 2 111CdHgNHZ 2 1.25 fuged samples. The heats of immersion are higher 4 1.53 for divalent ions; they increase in the order Na < 6 1.71 H < Ca, an order iii agreement with me;xiiremeiits Y 1.71 on kavlimites by Siefert? and others. 0 . 2 dl C4tlpNHZ.HCl 2 -0.36 A freeze-dried clay, as reported by Call," may 4 -0,G2 have similar surface areas to ai1 oveii-drietl clay. 0 -0.75 However, the consistently smaller amount of 8 -0.75 heat evolved by the freeze-dried clays indicates I n general, the magnitude of certain of the heats that there is a considernl)le rliffereiice i i i t4hephysiof immersion measured in thie study agree well with cal coristitritioii of these t'ivo clays. In a pre\'ious study3 it was foiiiitl tlintJ for the those of 0w:hareriko and Bykov,G aiul with the results of 8iel'erte7 The present measurement's ex- lower. amine salts, mi equi\xleiit nmoriiit of t'xcliringeahle cation was relenaetl for :I c e r h i 11n m ~ i i it8i t,eiitl both the accuracy of the determillatioil n i i c l of amine ion picked up by the clay. The 0.07 c d . (I\) P. D. Orrliarenko and S. l?. Bykov, Kolloid Z h w . , 16, 134 per g. of clay re1e:tsetl I)], the N;Lc:l:Ly-wtniiic I ~ J ~ u J ( 111,54). colilui-itle re;tvtfio:i xgi'tm I v i t l i t,licse enrlici. rwult,s. (7) .A. C:. Bicfcrt. 1'Ii.Ll. l'l~asih, L'uiiiisy1v;miu r j h t c Cullrgc, J!I 12. weighiiig, outgassing, heat of breaking aiid calorimeter performance. I n Table 11, the heats of reaction of three clay systems wit,h amine reagents is given. These values are obtained from Table I by subtracting the hettt of immersion in water from the heat of immersion in the reagent for each of the amine reagents.
1024
D. L. HILDENBRAND AND A. GREENVILLE WHITTAKER
the C;c clny-amine salt reaction shows negative heat i d t i e , (- 1.22 cnl.) indicating that coiisidernble energy is used up in replacing the Ca ion on the c h y by an amine ion. When the amine hydrochloride reacts with a clay it is concei\*able that the process is primarily ai1 eschange. Ho\ve-\.er, t,he interaction of an amine with a clay iiitroduces the possibility of adsorption of the amine to the CILZJ~without appreciable eschange. The resulting differelices in the energy chaiiges of these two processes are reflec,ted in the data obser\.ed nbo\.e. The 4.82 cnl. per g. of H-clay, relensed when immersed in butylamine, are equivalent to 7300 c d . per mole of hydrogen ion on the H111 contrast
:L
Vol. 59
clay. This arnouiit of heat is esseiitially the heat of neutralization between the amine ant1 the H-clay. I n an earlier study8 an entirely differeiit method gave 0,400 cal. for the heat of neutralization of a similar H-clay by NaOH. In addition to exchange aiid ntlsorpt'ioii, there are other factow which undoubtedly contribute to the heats of reaction-the dissocintioii of the exchangeable ion from the clay, the desol\ration of the amiiie and amiiie ion upoii reacting \vit,h the clay surfsces, niid the orientation of the hydrocnrboii cliaiu of the amine 011 the clay surface. ( 8 ) W. 1%. Slabaugli, J . A m . Chem. SOC.,74, 4402 (1082).
BUILNIN G RATE STUDIES. 11. VAKIXTION OF TERrIPElIA'L'UKE DISTRIBUTION WITH CONSUMPTION RATE FOE BURNING LIQUID SYSTEMS BY D. L. HILDENBRAND A N D A. GREENVILLE WHITTAKER C'hemist,y Division, U.8. Naval Ordnance Test Slation, In yokern, China Lake, Califomia Received April 6, 1066
Tlie thermocouple method has been used on several burning liquid systems to study variations in the teitipernture distribution brought about by changing the consumption rate. Data are presented showing the effect on surface and mauiinuiii gas temperatures and the results are discussed with respect to their possible significance. A thermal model for the coinbustion process appears to be compatible with the data and, in particular, a radiation and conduction tnotlel cnn be used to describe all or part of the temperature distribution in the condensed phase. funiiiig nitric acid atid conccnt,rnt,rcl sulfuric acid at, n pressuw of less than 2 millimeters of inei'cury. The rwultirig acid was analyzed and t,hen diluted to D5mo with distilled water. This ncid contained less than 0.1% nitrogen dioside. Enstinan Kotlak Go. white-lalwl ethyl n i t r a k \vas used without fwthei. purification. The purity of the metriol triiiitrate-t,i,incetiii mixture was nhout the s:me as that of the ethyl nitrate. Apparatus.-The nppnrstup used i n this study has hecn descrihed previously .I In nddi tion, several ot,her types of yecording instruments were used for t,eniperature mertsureniciit where possiljlr. A Snnlmm recording oscillograph WILS used at, low and iiiternietliate hurning i,:ttes, and a Leeds nud Nortjhrul:, Hpeedomiix tmortler wns used a t estreincly low rates in order to c,tiecli the cathode r;ty osc,il!osc,ope nieasui,ements. These two nddi tional i i i n t runient8s did not, have sufficient frequency response t o reproduce faithfully the clet8niled shape of t#hetemperature-time curve in most Experimental cases, but a compnrisbn of some of the teniprmture lcvels was possible. A comparison of the results from the t,hree Materials.-Two types of conihustihle liquids were in- different instruinent,s gave excellent agreement with respect vestigated. One consisted of the homogeneous binary sys- t o surface tempernture. .I11 of these nieasurement9 were tem 2-nitropropane-05% nitric ncid in which the oxidizer made with 7.5 p diameter platinum, platinum-lO% i,hoand fuel were in different molecules. T h e other type con- diuin t,hermocouples niounted in 3.7 min. inside-dinnieter sisted of ethyl nitrnt,e, and an 82y0 metria1 trinitrate (i.. ., closed-end Pyres tubes from which a temperature profilc methyltrimetliylolmct,haiie trinit,rate)- I 8 06 triacet,iii (i.e., \vas o1)tainetl as t,hc mnibustioii wave passed over tho glycerol triacet)ate)mixture in which the fuel itnd all the availThe iiiitinl teinperature of the liquid W:LS able oxygen wei'e in the same niolccule. These compounds 2thermocouple 5 " . The tcsult,iiig tempernture record is called the forwere of varying degrees of purity. The 2-nitropropane wtlrtl profile. A nioditied liquid holder was built 1rtt.w was prepared by disti1lat)ion of comnlercinl grade material, so that nfter the fot,\vai,d profile hntl heen recorded as aiid only the center fraction W ~ used. P This fraction had ail described above, the opening of a liquid filled reservoir index of refract,ion of 13950 at 20" using the sodium-D lines. conitected to the combustion t,ube nllovrd the burniug T h e literature value is given as 1.3041.3 Nitric acid was liquid to flow back u p the tube, again p:tssing over the prepared by distillation of a 50-50 mixture of C.P. white t,hermocouple, t,o give what is called a I'everse profile. This reverse profile gives the temperature record corre(1) D. L. Hildenhrand, A . 0.Whittnkev and C. B. Euntott, T I I I R sponding t,o stjartiny the theimocouple in t81ie ga.s phttse J O U R N A L .68, 1130 (1Y51). atJOVe t,lir: liquid nnd ending in the liquid phase tit) rooni (2) "Consumption rate" denotes tlie uhual itieaaured riuantity, teinlwnlure.
Introduction Previously a method was developed for obtaiiiiiig a reproducible arid reasonably accurate measurement of the temperature distribution i i i the coiideused phase of a liquid system burning in ai1 inert atm0sphere.l The method has beeii used to study the variation in temperature distribution as the result of changing consumpt,ion rate.2 Of principal interest were variations iii liquid surface temperature and maximum gas phase temperature, results for which w e reported liereiii. I t is hoped tjhat work of this type will help lead to an elucidation of the pi'ocesses involved in liquid combustion.
L e . . the linear rate of regression of the surface uncorrected f o r deviation of t h e shape of t h e liquid-gas interface from a plane surface. (3) "Handbook of Chemistry a n d Physics," Cliernical Rubber PuIIlisliinrr Co., 33rd Edition, p. 1077.
Results and Discussion At tlie outset it may lie well to make a statement
