Ida Mitsuo

井田 光雄

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231 The Science Reports of the Kanazawa University， Vol. II， No. 2， pp. 231-235 July， 1955 X-ray Studies on Long Chain Compounds SoIidified under an .t¥ltemating Eledric Field By Mitsuo IDA (Received January 25， 1955) In仕odudionX -ray studies on the fibre structure of long chain compounds solidified under an electrostatic field were performed systematically by Kakiuchi，ωbut simiIar studies using an alternating electric field seem never to have been made by any author so far as the prl田entauthor knows. The effect of an alternating electric field on liquid crystalline ρ-azoxyanisol was reported by Kast. (2) The author supposed that even if a long chain compound is solidified under an alternating electric field it would assume fibre structure owing to the anisotropy of the induced polarization provided the microcrystal had no permanent resultant dipole moment， and verified the correctness of the supposition by means of X-ray diffraction. E河>erimentalProcedure and Results The sample solidified between two nickel electrodes (diammeter: 12 mm) waS torn off and cut p巴，rpendicularlyto the plane into a thin plate (thickness 0.5 mm). The X -ray from a copper target was radiated without filter in a direction perpendicular to the electric field applied to the sample. The sample-plate distance was 4.6 cm. An alternating electric field of 60 c/s frequency and anothεr of about 300 k. c/s frequency generated by means of the appa.ratus shown in Fig. 1 were used as weIl as + Fig. 1. High frequency oscilator a constant electrostatic field for comparison. The intensity of the field was 6-8 kv / cm. Crude commercial sample was used in every case. It was found that the Debye rings obtained could be c1assified into three types， namely， type A which has intensity maxima in the direction of the electric field (Fig. 3， Fig. 5)， and type B which has intensity maxima in the direction perpendicular to it 232 M.IDA (Fig. 2， Fig. 4)， and type C with uniform rings. The results are tabulated， below. Table Electrostatic field 60 c/s 300 kc/s Paraffin ョA B? B? Cetyl alcohol A No No Stearic acid A A A Palrnitic acid (containing a few per田ntof paraffin) A B B Ethylsteaてate A A A Cetylpalmitate (containing a f色wpercent of paraffin) A A A Ye]]ow wax A B A 明Thitewax A B B Carnauba wax A B? B? Japan wax A No No No uni士ormring ? ambiguous Di即日目呂im潟The present author's classification was made the intensity maximum of Debye ring cOlTesponding to tlie (110) tlane which gave thestrongest reflection. Therefore both the A type axis perpendicular to the direction of the electric field) and the B type (αaxis para11elto the electric field) in the Kakiuchi's c1assification belongto our A type. The author's tentative explanation of the preceding exp吃rimentalresults is as follows. Microcrystals of cetyl a1cohol probably have p吃nnanentdipole moment as Kakiuchi believes， (1) and its direction must be per・Pぽ)ndicula1' to the chail1. A.l1d EO the chains wlIl orient perpendicular to theel己ctrostaticfield. But in an altemating electric field the chains wi1l not orIent on account of the permanent dipole moment. -This is the rea:間 nwhy cetyl a1cohol ShOW3 A type in an electIostatic field and a ul1iform ring in an alternating electric field. ( 一一一一一一一一-00.，-.--.一一一-a 一一一一一一--00-一一一一一一一…)一一一←ー ← 00一一一一一一一? ?Fig. 6. Double chain-length structuτe But in the other substanc田 themicrocrystals seem to lack permanent dipolεmoment for the fol1owing reasons. The paraffin molecule i3 non-polar. (b) AEphatic acids and esters are well known to form a double chain-length s仕ucturesshown in Fig. 6a so that dipole moment are cancelled. (c) The main constituent of yellow wax and white wax are meli明 Tlpalmitatesand that of carnauba wax is me1issylcε:rotate (d) Pahniti.c acicl and cetylpalmitaぬ weτemixed with a few pεr白川; of in order to rεducεthe size ofthe 80 a8 to make their fibr丹 structul巴c1earer. Such mixing i8 only meこhanicaland Vvil Eot the crystal structure.くのほ) The main constituent of Japan wax is tripalmitine for which Lutton訂正dothε-1'8 (<1)ベ5)X -ray Studies on LiJng Chain Com戸仰ds 233 間g酔 S飴dthe souble chain~lel!lgth sむuc士山'eas shown in Fig， 6b 釘ld開'，Uhemicroαystals of白lissubstance will have no陀 sultantelecttic moment.い〆Thereasons why. the miα。αys阻Isof these substances orient in an electrit f.ield ，.jlo spit泡 ofzero dipole moment may be due to their aniso位opicinduced polarization> 8ut. clear conclusion has not yet been obtained for社lereason why品ere.onIy . A type .0即ursin the case of an electrひstaticfield， whiIe the three types A， B， and uniform xingQ∞ur in an alternating electric field. unIy也efolIowing supposition s問団sto be. justifi吋 hAccording to Silberstein's 社leoryくの it is natura1 土o出inkthat thepolariz(lbility of a long chain molecul~ is larg~ inthe direction， of chain axis也anperpendicular句 ilt!.'Neve吋le】田s'the chains a1ways orient perpendicular tひ 7血ed加ctionof an.eleεtroataβc field. This seems to be due to t加 foIlowingmechanism. :ln the proces号ofsoIidification the ions∞ntained in the Iiquid sample w.iU a鈎明治lenear th~ microαystals as shown in Fig. 7， and the miαoαys士alswilI be polari:?ed，創1阜m'ty .the 10ca1 field due to出βionsbesides the external field. Now. we aSSume tb.at tJle L- mim町制S脱出時atedal叫也echain砥私利昭胸intensity of the local field is strong町 when吐lelong chains + + + + C工E 町 i倒泊 thedirection抑制i叫紅白 the位 t吋 field一一一一 位lanoth町wise.Therefore the long chain will orient t!j.，世間1- direction p阿ぽ的p戸叩n凶1Fi抱g， 7， by thβIoce'l  field rather出組 itsanisotropic pol町 iza¥l:iIty.This is the ca田 ofA type in an electrostatic field. 1n the case. o:f an' a比ern:atingelectric field if the ions near the microcrysta1s can be quickly 回placedby'ions of the opposite sign in はepwith the frequeまlCyof the alt怠rnating'el配tricf也ld;the chains wiIl stiI1 orient in the direction perpendicular . tothe . external field. 13ut when the ions can no生beexchanged quickly on accoun士mainlyof insufficiency of the number of ions， the effects of positive and negative ions are canceIIed and the molecules wilI be polarized mainly by the external field， and the chain wiI1 orien士inthe direction of the ext町na1field. This is the case of B type. If both the above mentioned causes of A type and B type are present and can田Iledeach other or the anisotropic polarizabiIty of molecule is not so conspicious， nearly uniform rings wiIl appe官.For example they are seen in carnauba wax and J apan wax. 1n addition sοme few details wiI be given. White wax showed A type by the alternating electric field of low frequency 1.5 c/s， and when a minute quantity 234 M.IDA cOnffigulation which is formed in the solid state. Let Pl be the polarizability in the direction of chain axis，れ that in the direction perpendicular to it in the plane of the chain and P3 that in the direction perpendicular to both， then we can obtain the following values. Pl = (24.2n十1.8)X 102生cm3P2 = (19.4n十 6.6)X 1024 cm3 P3 = (14.6n十 11.4)X 102生cm3If we put n = 20， then Pl : P2 : Pg = 49: 39 : 30. Thus we can know that the anisotropy of the polarizability of n-paraffin is not so conspicious and even in the best condition the fibre structure of B type wiIl not be so marked. The author wishes to express his sincere thanks to Professor H. Shoji for his kind gu.idance. He also expresses his gratitude to Mr. T. Tomoyasu for his cooperation. A part of th色 expencesof. the experiment was defrayed by Nishikawa Co. to which thanks are due. R哩feren記官自(1) Kakiuchi Sci. Pap. 1. P. C. R. 40 (1943) 189. 白) Kast (3) Yosida (4) Lu抗:onZ. f. Phys. 71 (1931) 39. Proc. Imp. Acad. Tokyo 18 (1942) 377. J. Am. Chem. Soc. 67 (1945) 524. (5) Clarkson & Malkin: J. Chem. Soc. (1934) 666. (6) Silber邑tein: PhiL Mag. 33 (1927) 92， 215， 521. (7) Stein: J. Chem. Phys. 21 (1953) 1193. X -ray Studies on Long Chain Comρounds 235 Fig. 2. Paraffin (300 kc/s) Fig. 3. Ethylstearate (60 c/s) Fig. 4. White wax (60 c/s) Fig. 5. Cetylpalmitate (300 kc/s) 

X-ray Studies on Long Chain Compounds solidified under an Alternating Electric Field

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X-ray Studies on Long Chain Compounds solidified under an Alternating Electric Field

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