10
Injection of high-energy positrons into liquids and polymers such as water, toluene, and polyeth- ylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in certain amount. Ps can be regarded as an electrically neutral particle with ex- tremely small mass and is an interesting object for research in radiation chemistry. A scientific field dealing exclusively with the formation and annihila- tion of Ps in condensed matter is called posi- tronium chemistry. In this paper positronium chem- istry studied in the author’s laboratory in the last few decades is reviewed. The peculiarities of Ps in liquid-phase chemical reactions and its formation process in polymers are highlighted. Applications of the unique properties of Ps to polymer characteri- zation are described. Key words: positronium, liquid-phase reaction, poly- mer, positron spur, free volume 1. ῎ῌ῏῍ 腻膇膏腽腃腝腀膅膏腻膒膋膎腻膃膐膒腤 膗臰腭腢腝腀腧膉膀腦腑 腶腮腠臈膤膲臬腔腵腠腕腫腎腓腦膲臬臀臒臷 腝腀腝腀膂膈腃腷膮臢腗腴膂膈腃腢腧腼膒腥腱腞腠腏腲腛腛腑腔腵腛腹腼膒 腤腣腦膣臡膚膡臏腔腁臭臁腗腴腦腓腢腡腌腳腝腀膂膈腃腡腧腹腼膒腝腀臌臧膚膡腖腴腝腀膈腃腝腀腝腀臃臊臟腥腱腞腠臑膓腏腲 腛腛腑腜腔腵腛腟腐膯膾腗腴腓腢腥腱腴膮臢腡腌腴e e [e e ] 腓腓腡[e e ] 腟腦腝腀腟腦膯膾臠臨膱臃臜臲腕腠腍腴腓腦臜臲 膋膁膅膑膆腺膌 (Ps) 腨腵腠腍腴Ps 腔腒腷腯腛腤腍臸臡腢腬腤腘臌臧膚 膰膩臱臚腢腕腠膫臓臩腡腦 Ps 臣臢膰膩腗腴腘腏腙膋膁膅膑膆腺膌膚膡腸腡腍腴 1), 2) Ps 腥腧腝腀腦膂膉膒腦腇腣腥腱腳腟腦臭臁腗腴腝腀腦膂膉膒腐腍腥腉腐臜臲腧膈膍膋膁膅膑膆腺膌 ( p-Ps)膂膉膒腐腍腥臜臲腧腼膏膅膋膁膅膑膆腺膌 (o-Ps) 腨腵腠腍 臺臛1:3 膢膾o-Ps 腦腪腎腐臣臢腗腴腝腀腙腦臑膓臊臟腦膂膉膒腢臱膹腑腦膂 膉膒腷腯腞腛臭臁腗腴腢臶臈膤臱臘腕腠 2 g 腗腴腓腦腛腮p-Ps 125 ps 2 g 臊膵臘腗腴腓腵腥膂膉膒腦腷腯腛腤腍 o-Ps 臞膭 腡腧 142 ns 3 g 腕腠臊膵臘腗腴膫臓臩臸腡腧o-Ps 腝腀膯膾腕腠腍腴臩臎 腡腧腤腒臑膓腔腵腠腍腴膂膉膒 腗腴膞臻 膉膄腾腼膊腥腤 o-Ps 15 ns 腫腡臶臓腔腵腴腡腧腞腠腑腛膰膩腏腲膗臩臸 腦膋膁膅膑膆腺膌膚膡腈腀 腇臃臸腦膋膁膅膑膆腺膌腈腀 腇膋膁膅膑膆腺膌膚膡腩腦腥腟 腍腠臙膟腗腴膗臩臸腦膋膁膅膑膆腺膌膚膡腡腧Ps 膚膡腵腴臃膸膜腥腟腍腠腀腇臃臸腦膋膁膅膑膆腺膌膮臢腡腧Ps 膮臢腗腴 腟腦臌臧膚膡膞臻腥腟腍腠腙腵腚腵腗腴臀膷膋膁膅膑膆腺膌膚膡腩腦Ps 膔臡腞腜腕腛臰臥腤腣 Positronium Chemistry and Its Application to Polymer Characterization Yoshinori KD76N6H=> (National Institute of Advanced Indus- trial Science and Technology) 3058565 腟腒腨臄111 臂膬膧臕自膾膰膩臖腟腒腨臸 膘臵 5 臆膬臖 84 (2007) 3

Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

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Page 1: Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

Injection of high-energy positrons into liquidsand polymers such as water, toluene, and polyeth-ylene results in the formation of positronium (Ps),the hydrogen-like bound state between a positronand an electron, in certain amount. Ps can beregarded as an electrically neutral particle with ex-tremely small mass and is an interesting object forresearch in radiation chemistry. A scientific fielddealing exclusively with the formation and annihila-tion of Ps in condensed matter is called posi-tronium chemistry. In this paper positronium chem-istry studied in the author’s laboratory in the lastfew decades is reviewed. The peculiarities of Ps inliquid-phase chemical reactions and its formationprocess in polymers are highlighted. Applicationsof the unique properties of Ps to polymer characteri-zation are described.

Key words: positronium, liquid-phase reaction, poly-mer, positron spur, free volume

1. ����

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22) [eeef] �^_ ���J^_ ���`a.Dhi��j b�cd�k.$&<1 2 b�cd� l�mnop (Ps)�qr-$&<1 Ps� s�Jt,u �v�wD�&xG���y�z �RS?H {|}~�.$���&1 ���) Ps U:��T�{|;<H���� � l�mnop?H� �q�)&<1), 2)1

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� gS��E;<1 2 D# p-Ps���J%u125 ps) 2� gS�Y���;<1 2-�}. ���7�� ���wD�& o-Ps���J�u ��x)� 142 ns) 3� gS��E.$Y���;<1���x)� o-Ps� ���J `a.$&<�� ��)��u [\ ���b�,-$&<�7�� �����;<�� ����>���� J��X��O o-Ps ��� 1 5 ns��/)¡��%�,-<1�¢)� �£ �A$!D{| xBC ���x l�mnop?H� ����x l�mnop9:� � l�mnop?H ����¤¥ T�� �_&$¦§;<1 ���x l�mnop?H� )�Ps ?H�T�¨-<�©���ª«�_&$ ����x l�mnop9:� )� Ps9:�¬;<�_ �RS?H���_&$ �-­- ® ;<13¯ � l�mnop?H ����¤¥ T�� )� Ps �©G�!�.D��� Y"�°#±��

Positronium Chemistry and Its Application to PolymerCharacterizationYoshinori KD76N6H=> (National Institute of Advanced Indus-trial Science and Technology)�305�8565 _ur²$ 1�1�1 ³´µ¶·a{|¸_urx¹º 5»´¸

º 84¼ (2007) 3

Page 2: Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

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Page 3: Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

��� S��������� ������������ �� 2�� p-Ps������ !"#���$%& '(�)*$+,-.�#��/0���-.1!�#�2 o-Ps134567#�89:�& #�g;1<4=��>�?�@�� A1$%& p-Ps1BC��DE��0& S�������FGH��� I$&�-.1!�#�J�& �-.1K?8LM��NO8P*�#��/0��-.1'(������A0� &<4=��>�?QR8P?�-.1KS8LM��NOTR��A0�JG��UV& WX1GeYZ[�� 21#� g;T\]Q��^_`ab`c<4=��>�?QR�de��Pf8�?& g09:�& hijk�lmn�oH& S/N 91ob��p�A0�JG�Pf8�*��3)�

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Page 4: Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

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3.2 ���������� ������Ps������ �!"#$%&'()� *+,�-.��� Ps���/0M�1�2345�67�� ���5-.�8��&'(9:�� *+,�Ps���/0�-.;<)� �=�2�>� ��9� -.�8��9)=��?@%� AB8�C<���D%�� E 5) p-FGHIJG� Ps��8�C<�� �=��K;�LM"�9:��� N�2=��?@%� AB8�C<���D%���� Ps�p-FGHIJG����-.�89:����L���6)� ��O�� Ps�PQRFGSG���9)� � �=����8�C<)#$2)+K��%� TU1V� M�WX� =�� 0.65 mNs/m2�FGSG,9)8�C<� 26 dm3/mol nsY1������ -.�8��&'(9FGSG�����8�C<��Z@[�=�� 0.229 mNs/m2 �\G]G,�8�C<) 0.48

dm3/mol nsY1�^2?@D%�����PQRFGSG� Ps��_�� ���`� �2)� � ��WM��2 Ps�ab�B��52cd@[���eW�6��:�5), 6)� Ps)f��gh2?@�Mi� j�kl2mnoi�5� ��SRpqr(st���D%�� ��Mi� Ps)*u,9v/vw�x�2yz(�{X[�k|�}~ �� *u,2�� R�k|�}~ ��26�%qr(st�� �U�� s��� 4psR29U ��2 ��� Psyz(��qr(st Etotal)

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Page 5: Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

��������� p-�� ��� Ps�������������� p-�� ��� Ps������������ �!"#$�� %�&'� �()���*� Ps� p-�� ���+,-&�$�./�Ps01�234��&'����5���$�6 7�78���*����� �� Ps����/92���:���;)<�=�;&>�������:��?@A1� ��/9 k�:��BC��>�#$��-)@� 5��:��#$���DE���� �� Ps01�234;F�@5�2G;)@� ���:�� 26 mN/m �H!"#$����IJK�L�M@)@��� 5����*� Ps����� ��+,-&�$� Ps01�234��N��O #$��"� ���������-&&'������ PQ� 6 7R�:� 26

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700 kg/cm2 u� 700vdw x�Cd�������/9� 1.6 dm3/mol nsy1R� 36 dm3/mol nsy1x�zs�T{�� 5���;� �*� k�Cd;)> 26 dm3/mol nsy1�D�|E}/��� j k�*� k�T{����� Psfgh�di]�) Ps�~�h�J�BC��&'��"� :��#$�� �*��Cd;)@�@���������������-&&'�����/9�D�|E�0;�R-&5�2G;)@�7)}��� �����4���'�c��Z[��b������ Cd�!"��o�BC;� ��c�BC2��������/9�Z[�� ����/9�d�mno�� �� Evans�Polanyi���!-)� �����c��0 DV����V���

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cm3/mol ������8)� 6 8�j k��b�?d�����P�qa�5��2������ DV �y329 cm3/mol��� 5����#$�c��i����� Ps���*�fgh�@�#$���234;)@�5���� %>%>fgh34�� Ps�������t]@*o���;) ��5�R��_�e¡��"� %���o�¢��#$�d�mno�Ps������`a u���_£'`aw �!��q �$�7)

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¤ �*� Ps�� !"�¥¦J���!"� !"��"��q1;)�4�� u?§�#¨©ª¨]�&¤ �*�$«"��!"��¥¦J¬�q1;) Ps2

� 7 78���*����� �� Ps����/9����:���� E total�0.242 � ss [eV] R�%��& Psfgh�­~�h�J>G;)��5) j k®h¯�� �*�����/9�°�����()t]�� 5���*�� Psfgh�&¬s�./�����-)@�±'o���

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1) ��-¯0�°o� �9�±²7�%z³��1993.

2) O. E. Mogensen, “Positron Annihilation inChemistry,” Springer Verlag, Berlin, 1995.

3) ��´µ� >?�No� 69, 41 (2000).

4) Y. Kobayashi, T. Nomizu, and Y. Ujihira, J.Am. Chem. Soc., 101, 537 (1979).

5) Y. Kobayashi, J. Chem. Soc., Faraday Trans.,87, 3641 (1991).

6) Y. Kobayashi and Y. Ujihira, J. Phys. Chem.,85, 2455 (1981).

16 �x�,�-� S ������ o-Ps#�¶1 I3�!"27)� 1: ,�1#$ª·()(HDPE), 2: �,�-�#$ª·() (UH-MWPE), 3: 2�1#$ª·() (LDPE), 4:?"@�� PE, 5: ?"@�� PE, 6: PC, 7:#$��`$L1�·L (PMMA), 8: #$¸YL�L��L (PVA), 9: PET, 10: #$ª�¹Lª�¹Lº7) (PEEK), 11: K%7)

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Page 10: Injection of high-energy positrons ... - Radiation Chemistryylene results in the formation of positronium (Ps), the hydrogen-like bound state between a positron and an electron, in

7) Y. Kobayashi, Chem. Phys. Lett., 172, 307(1990).

8) C. Reichardt, “Solvent E#ects in OrganicChemistry,” Verlag Chemie, Weinheim, NewYork, 1979.

9) C. L. Wang, T. Hirade, F. H. J. Maurer, M.Eldrup, and N. J. Pedersen, J. Chem. Phys.,108, 4654 (1998).

10) Y. Kobayashi, C. L. Wang, K. Hirata, W.Zheng, and C. Zhang, Phys. Rev. B, 58, 5384(1998).

11) L. Onsager, Phys. Rev., 54, 554 (1938).

12) J. Terlecki and J. Flutak, Int. J. Radiat. Phys.Chem., 4, 469 (1972).

13) C. L. Wang, K. Hirata, J. Kawahara, and Y.Kobayashi, Phys. Rev. B, 58, 14864 (1998).

14) Y. Kobayashi, W. Zheng, K. Hirata, and T.Suzuki, Radiat. Phys. Chem., 50, 589 (1997).

15) W. Zheng, Y. Kobayashi, K. Hirata, and T.Suzuki, Radiat. Phys. Chem., 51, 269 (1998).

16) Y. Nagai, T. Nonaka, M. Hasegawa, Y.Kobayashi, C. L. Wang, W. Zheng, and C.Zhang, Phys. Rev. B, 60, 11863 (1999).

17) M. Tachiya, J. Chem. Phys., 70, 2021 (1979).

18) K. Sato, D. Shanai, Y. Hotani, T. Ougizawa, K.Ito, K. Hirata, and Y. Kobayashi, Phys. Rev.Lett., 96, 228302 (2006).

19) H. Nakanishi, S. J. Wang and Y. C. Jean, “Posi-tron Annihilation Studies of Fluids,” ed. by S.C. Sharma, World Scientific, Singapore, 1988,p. 292.

20) S. J. Tao, J. Chem. Phys., 56, 5499 (1972).

21) M. Eldrup, D. Lightbody, and J. N. Sherwood,Chem. Phys., 63, 51 (1981).

22) Y. Kobayashi, W. Zheng, E. F. Meyer, J. D.McGervey, A. M. Jamieson, and R. Simha,Macromolecules, 22, 2302 (1989).

23) K. Hagiwara, T. Ougizawa, T. Inoue, K.Hirata, and Y. Kobayashi, Mater. Sci. Forum,363(3), 337 (2001).

24) T. Oka, K. Ito, C. He, C. Dutriez, H. Yokoyama,and Y. Kobayashi, to be submitted.

25) Y. Kobayashi, K. Haraya, S. Hattori, and T.Sasuga, Polymer, 35, 925 (1994).

26) M. Muramatsu, M. Okura, K. Kuboyama, T.Ougizawa, T. Yamamoto, Y. Nishihara, YSaito, K. Ito, K. Hirata, and Y. Kobayashi,Radiat. Phys. Chem., 68, 561 (2003).

27) K. Ito, Y. Kobayashi, and A. Nanasawa, Appl.Phys. Lett., 27, 654 (2003).

28) K. Sato, K. Ito, K. Hirata, R. S. Yu, and Y.Kobayashi, Phys. Rev. B, 71, 012201 (2005).

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