林 英子

<p>千葉大学では平成26年度より文部科学省大学教育改革加速プログラム（AP）タイプIII（高大接続）「次世代才能スキップアップ」プログラムを千葉県内及び近隣都県高等学校と連係し実施してきた．この中で高校生を対象とした国際研究発表会を実施してきた．これは高校生が研究発表を海外の研究者・留学生に対して英語で行うものである．今回，平成28年度から平成30年度に参加した高校生の気づきと学びについて，アンケートの記述をテキストマイニング法により解析した．この結果，生徒は英語での会話に関して難しさを感じるとともに，研究発表は成功したと感じていることが示された．本プログラムは生徒に英語コミュニケーションの重要性に気付かせ，英語発表の自信につながると考えられる．</p>

<p>Chiba University has carried out a student exchange program called "Twin college envoys (TWINCLE)" as part of Japan's re-inventory project with the support of MEXT since 2012. The TWINCLE program has 12 partner universities in 5 ASEAN countries—Indonesia, Thailand, Singapore, Cambodia, and Vietnam. During the 5 years of the program, 246 ASEAN students visited Japan. This study analyzes the effect of the program, focused on the influence on the careers of ASEAN students through the program activities, using students' comments in activity reports from 2013 to 2016 using text-mining methods and subsequently cluster analysis methods. The results suggest that ASEAN students were interested in each activity in the TWINCLE program and had good impressions after participating in the program.</p>

[要約] イオンからなる物質は，高校でも学習するとおり，結合が強く融点が高いことが知られている。近年,イオンからなる物質であるが常温で液体状態をとるイオン液体が着目され,高校教科書にも参考として取り上げられるようになった。本研究では，新規な物質であるイオン液体について特徴を説明し，先行研究の結果を利用して，その性質について視覚的に理解する実験教材について検討した。作成した教材を５名の高校生に対して実施した結果，新規物質であるイオン液体の性質や示す現象の面白さについては伝わったものの，内容の理解については，事前にイオン結晶についての理解を深めておくなどの改善が必要であることがわかった。

<p>The TWINCLE program is a teacher internship program which aims to enhance mutual understanding of foreign cultures and to develop students' ability to succeed in overseas internships. In this study, reports written by students who participated in the program were analyzed by a text mining method to evaluate the changes in their ideas about the development and practice of the teaching materials. The results indicate that the students' attitudes towards science classes changed from 'simple lecture oriented classes' to 'problem-solving learning oriented classes'. Therefore, participating in the TWINCLE program is an effective way to change the students' image of the science class.</p>

ボルタの電池の反応は,正極での水素の発生については実感が湧くが,負極での亜鉛の溶解は,亜鉛イオンが無色であることもあり実感が湧きづらい。この電池の亜鉛の溶解反応を,キレート金属指示薬であるキシレノールオレンジを使って可視化した。60分間の映像を12秒間に圧縮して観察すると,亜鉛の自己溶解反応に加えて,電池反応による亜鉛の溶解の促進が観察された。電池の電流が外部回路を流れるのに対応して,電解質溶液内での亜鉛イオンの移動が観察された。

The magnetic effect on the phase transitions of n-C22H46 (docosane) was measured using a high resolution and super-sensitive DSC. The surface freezing phenomenon was observed at about 3 K above the 'bulk' melting temperature in addition to solid-solid transitions and melting transition. The transition temperatures due to the solid-solid transitions and melting were shifted to higher temperatures by about 10 mK by applying magnetic field of 5T. On the other hand, the transition temperature due to surface freezing phenomenon was shifted to lower temperature by about 10 mK by applying magnetic field of 5T. The magnetic effects were discussed based on the extension of the Clapeyron equation. (C) 2013 Elsevier B.V. All rights reserved.

塩化カリウムは水溶液から結晶を作ると,食塩と同様の四角い形状の結晶ができるが,多孔質固体上では意外性のある繊維状結晶が生じる。寒天ゲルを用いて繊維状結晶の生成条件の検討を行ったところ,3wt%の寒天を含む3mol/Lの濃度の塩化カリウム溶液をビーカーに1cmの高さまで入れ風乾すると繊維状結晶が30～50日間で成長した。繊維状結晶の成長には高湿度を保ちながら溶媒を蒸発させることが重要であり,ビーカー内の上部空間がこの結晶成長条件を保っていることがわかった。アクリルパイプを用いて,結晶の生成する日数を2週間程度に短縮する観察用器具を作成した。

青色顔料であり混合原子価錯体であるプルシアンブルーの色の変化を用いて,酸化還元反応において以下のことを体験・認識できる実験ワークシートを作成した。 試験管内での反応と,乾電池を使った直接の電子授受としての反応の両方を観察することができる。 酸化と還元は同時に起こる反応であることが確認できる。 「酸化剤・還元剤」,「電気分解」,「電池」を統一的に電子の授受として実感できる。 鉄イオンの価数が酸化数に相当することから,酸化数の増減で酸化還元を説明できる。作成したワークシートを用いて,高校生,中学生への実践を行った。

With the support of JST we carried out research into developing a study program, "Fostering Next-Generation Scientists". This program for fostering talented young scientists, which was created by Chiba University, selects and trains participants in two stages. The program offers its participants the opportunity to experience advanced lectures and conduct experiments in the fields of Physics, Chemistry, Mathematics, Engineering, and Life Sciences. We are currently carrying out courses from the first to the third stage. There were 470 applicants for the program, of which 28 have completed the whole curriculum. Those who completed the program have given presentations on their research. They have also entered scientific essay competitions and won various awards such as a prize for excellence. Chiba University's program for fostering talented young scientists has been effective in selecting and developing the talents of students with a spirit of independence and perseverance.

ビーカーをアルコールランプで加熱すると,加熱の最初にビーカーの外側が曇る。この現象を,2007年度の教育学部小学校課程の小学校理科受講生に実際に観察させ理由を問うたところ,答えられた学生は皆無であった。私達が日常生活で普通に目にする炎を伴う燃焼では,二酸化炭素の他に水も発生している。このことは中学校理科で学んでいることであるが,日常生活で観察される現象の理解に生かされていないことが分かった。

The melting transition of Ga and In was measured by using a nW-stabilized differential scanning calorimeter working in a magnetic bore. The magnetic effect on the thermometer was about 18 mK at 5 T, which was corrected for the measurement of the magnetic effect on the melting transition of Ga and In. The melting temperatures of Ga and In with the magnetic field of 5 T were obtained to be 8.3 and 10.2 mK, respectively higher than those without the magnetic field. These results show that the solid phase to be relatively more stable under the magnetic field. The calculated temperature shifts of the melting transition due to the magnetic field using the magneto-Clapeyron equation and the reference data of magnetic susceptibility were negative values for both Ga and In, being contradictory to the experimental results. © Springer-Verlag 2006.

The phase transitions of even n-alkanes, n-C H , n-C H , n-C H and n-C H with high purity have been measured using a high resolution and super-sensitive DSC. A new transition in the low temperature phase was observed in all the samples in the heating run. The surface freezing phenomenon was observed by thermal measurement for the first time in all the samples both in the heating and in the cooling run. The difference of the thermal behaviors between the heating and cooling run was also observed in all the samples. © 2006 Elsevier B.V. All rights reserved. 34 70 36 74 40 82 42 86

We have developed an apparatus, which can measure heat flux and dielectric constant simultaneously. The heat flux and the dielectric constant of a single crystalline BaTiO were simultaneously measured with a temperature resolution of milli-Kelvin to study the detailed behavior of the phase transition. The anomalies are observed between 400 and 402 K both in the heat flux and the dielectric measurements with a close correlation between the heat flux and the dielectric constant. A slow increase and a sudden jump in the dielectric constant were observed in the heating process and at least five thermal anomalies were observed between 400.3 and 401.2 K in the cooling process. The unstable state was observed in the vicinity of Curie temperature keeping at a constant temperature both in the heating and cooling process. The hysteretic behaviors of the phase transition and the unstable state were discussed in terms of two-phase domains in the transition. © 2005 Elsevier B.V. All rights reserved. 3

The phase transitions of dipalmitoylphosphatidylcholine (DPPC)-water and DPPC-CaCl aqueous solution system were investigated in the both directions of heating and cooling process by means of a high resolution and high-sensitivity differential scanning calorimeter. The peaks due to the transitions showed different features between heating and cooling runs, especially for the pre-transition and the sample with a high Ca concentration. A sub-main transition in multilamellar bilayers of DPPC was detected in addition to the pre-transition and the main transition. The addition of Ca ion affected the pre-transition and the sub-main transition as well as the main transition. © 2005 Elsevier B.V. All rights reserved. 2 2+ 2+

The magnetic effect on the ferroelectric transition of single crystalline KD PO (DKDP) was measured by using a high resolution and super-sensitive differential scanning calorimeter (DSC) working in a magnetic bore. The transition temperature of KD PO with the magnetic field of 5 T along a-axis and along c-axis was 5.6 ± 0.8 and 2.8 ± 0.9 mK, respectively, higher than that without the magnetic field. The calculated temperature shifts of the transition due to the magnetic field along a-axis and along c-axis using the magneto-Clapeyron equation and the data of magnetic susceptibility were negative values, being contradictory to the experimental results. These results demand to consider another contribution in magnetic susceptibility. The high frequency term of magnetic susceptibility due to molecular motions was considered to play an important role in order to explain the positive experimental values. © 2005 Elsevier B.V. All rights reserved. 2 4 2 4

Thermal expansion coefficients of yttria stabilized zirconia(YSZ) with the Y O content of 3, 6, 8 and 10 mol% were measured using a push-rod type dilatometer in the temperature range from 103 to 876 K. The thermal expansion coefficient of YSZ decreased with the increase of the Y O content. The thermal expansion coefficient of YSZ was theoretically estimated for the various Y O contents using the values of isochoric heat capacity, molar volume, isothermal bulk modulus and the Gruneisen constant in a good agreement with the experimental results. Among the physical properties, the bulk modulus is considered to be mainly responsible for decreasing the thermal expansion coefficient of YSZ with the increase of Y O content. The doping effect of Y O in YSZ on the thermal expansion coefficient was discussed using a molecular dynamics simulation. © 2004 Elsevier B.V. All rights reserved. 2 3 2 3 2 3 2 3 2 3

日常の疑問や自然の探究に関して, 一般に広く説明されて分かっていると思われていることでも, 本当には正しく説明されていない場合がある。本研究では1円玉が水に浮く理由について説明している書籍や, webサイトの記載について調べ, また, 実際に実験を行い浮力と表面張力の寄与について考察を行った。その結果, 1円玉は上向きに働く水の表面張力と, 1円玉が水表面より低い位置にあることにより生じる浮力の両方の力により水面上に浮くことが分かった。

熱流束型DSCにおいて,温度センサーに半導体熱電素子モジュールの採用,±1mK以内の断熱制御,±0.1mK以内の昇降温制御,試料セル近傍の温度変動を±0.1μKのオーダーとするための温度減衰方法の採用,計測系へのノイズ,迷起電力が±1nVのオーダーとする工夫により,ベースラインの安定性±3nW程度,装置の応答速度2s程度で,装置の温度分解能0.1mK程度のDSCを製作した。このDSCを用いて,μgのオーダーの試料量のパルミチン酸とドトリアコンタンの融解挙動を測定した。試料量が減少するにつれて融点の低下が観測されたが,これは試料分子と試料容器との相互作用によるものと理解される。また,ドコサンの測定では,液体上単分子層の存在の検出や新しい多段階相転移や相転移の微細構造の検出に成功した。

The magnetic effect on the melting transition of H2 O and D2 O was measured by using a high resolution and supersensitive differential scanning calorimeter working in a magnetic bore. The melting temperature of H2 O and D2 O at 6 T was 5.6 and 21.8 mK higher than that without the magnetic field, respectively. The temperature shifts of the melting transition of H2 O and D2 O were proportional to the square of the magnetic field. The temperature shifts of the melting transition due to the magnetic field did not obey the magneto-Clapeyron equation quantitatively. A dynamic effect due to the magnetic field was discussed for an alternative interpretation. © 2004 American Institute of Physics.

Structure-property correlations of the following model compounds for oligomer liquid crystals (LCs) have been investigated: monomers, C H O(CH ) CH (x = 4 and 5); dimers, C H O(CH ) OC H (x = 3, 4, 5, and 6); and tetramers, C H O(CH ) OC H O(CH ) OC H O(CH ) OC H (x = 5 and 6). Deuterium NMR quadrupolar splittings observed from the deuterated model compounds dissolved in a nematic solvent, 4′-methoxybenzylidene-4-n-butylaniline (MBBA) or p-azoxyanisole (PAA), were analyzed by the rotational isomeric state scheme with the maximum entropy method to yield the orientational order parameters, bond conformations, and molecular dimensions. For the dimers in particular, the solute shapes were estimated from phase diagrams of the dimer/MBBA systems, the crystal structures were determined by X-ray diffraction, and the melting points and enthalpies of fusion were evaluated from DSC measurements. From the dimers, the so-called odd-even effect was clearly observed in not only the orientational order and molecular shape in the nematic solution but also the crystal structure and thermal properties; that is, the dimers of x = 4 and 6 have larger order parameters, more anisotropic shapes, better-arranged crystal structures, higher melting points, and larger enthalpies of fusion than those of x = 3 and 5. In the nematic solution, the model compounds preserve the inherent conformational preferences of the ether chain and enhance the shape anisotropy by increasing the trans fractions. As the orientational correlation is expected to persist only within a short range, conformations of the tetramers may represent those of polymer LCs with the same ethereal spacers. The chainlike molecules adjust their spatial configuration to the LC environment, and consequently, physical properties of the LC system are affected. 6 5 2 x 3 6 5 2 x 6 5 6 5 2 x 6 4 2 x 6 4 2 x 6 5

水は我々にとって一番身近な物質であるが, 液体としては特異な性質を持っている。この特異な性質を持つ水の液体状態, 固体状態での特性を理解する教材に, 分子動力学シミュレーションを適用した。氷が融けて水になる様子や, 氷という固体状態であっても原子が運動している様子を分子動力学シュミレーションの結果を用いてアニメーションとして視覚化した。アニメーションで見た分子の配置状態や原子の速度などをグラフにして, 氷や水の性質を整理して認識できるようにした。実際に氷の融解の様子のアニメーションを用いて授業実践を行った。

The phase transitions of n-C H have been measured by using a high resolution and super-sensitive DSC. The crystal-rotator transition and the rotator-melt transition were observed both in the heating and in the cooling run, although a rotator-rotator transition was observed only in the cooling run. A new peak was found at about 3 K above the 'bulk' melting temperature. It is considered to be due to the order-disorder transition of a monolayer on the surface of the liquid alkane. When the cooling rate was below 0.1 mK s , the peak due to solidification was separated to give another phase transition. © 2003 Elsevier B.V. All rights reserved. 22 46 -1

Phase transitions of the N-p-ethoxybenzylidene-p′-butylaniline (EBBA) were measured by means of a high-resolution and super-sensitive DSC. The crystal to liquid crystal transition and liquid crystal to isotropic liquid transition was observed at 305.8 and 352.4 K at a heating rate of 1 mK s , respectively. The crystal to liquid crystal transition was found to have fine structures resulting from different crystalline states of the sample which depended on the sample preparation and on the heating rate of the measurement. The temperature due to liquid crystal to isotropic liquid transition was raised by 34 mK by applying a magnetic field of 5 T. The magnetic effect was discussed based on the extension of the Clapeyron equation. © 2003 Elsevier B.V. All rights reserved. -1

The heat flux and the thermal expansion of BaTiO were simultaneously measured with a temperature resolution of milli-Kelvin to observe the multistage transitions. Heat flux was detected by the thermomodule and thermal expansion was detected by observing the change of capacitance due to the change of the sample length. At least six thermal anomalies were observed between 402 and 405 K in BaTiO simultaneously in heat flux and thermal expansion in the cooling process. The correspondence of the anomalies observed in the two physical properties was excellent. The thermal expansion curves along 〈0 0 1〉 direction obtained at the cooling rates less than 20 μKs consisted of several steps with different number and magnitude depending on the cooling rate. The hysteresis behaviors for the phase transition of BaTiO are discussed in terms of domains. © 2003 Elsevier Science B.V. All rights reserved. 3 3 3 -1

A high resolution and super-sensitive differential scanning calorimetry (DSC) has been constructed by using two kinds of semi-conducting thermoelectric modules; one is used as a high-sensitive heat flow sensor and the other is for a main heater or cooler using the Peltier effect. The baseline fluctuation of the calorimeter was within ±25 nW. Thermal analysis of n-C H was conducted using this DSC and two large peaks due to the solid-solid transition at 339.1 K from the crystalline phase to the rotator phase and the melting transition at 341.9 K were observed at the heating rate of 0.4 mK s . In addition, a small peak was detected first by DSC at 338.1 K, indicating a high sensitivity of this DSC. In the solidifying process from the melting state at the cooling rate of 40 μK s , several small exothermic sub-peaks were observed in addition to the main solidifying peak. © 2002 Elsevier Science B.V. All rights reserved. 32 66 -1 -1

A high-resolution and super-sensitive DSC measurable under strong magnetic field has been constructed in the magnetic bore of a refrigerator-cooled superconducting magnet. The baseline stability of the calorimeter was about 20 nW. The magnetic effect to the phase transitions of n-C H was measured using the calorimeter. The transition temperatures due to solid-solid transition and due to melting were shifted to higher temperatures by several tens of mK by applying the field of 5 T. The temperature shift due to the magnetic orientation was discussed based on the extension of the Clapeyron equation. © 2002 Elsevier Science B.V. All rights reserved. 32 66

銅板上に亜鉛を析出させて銀色にし, それを加熱して金色にする反応は中学校の一部で化学教材として用いられている。この実験教材において, 銅板上への亜鉛の析出機構を検討し, 銅と未反応の亜鉛が局部電池を構成することにより亜鉛の析出が起こることを確認した。局部電他反応を視覚的に理解できるように教材としての工夫を行った。

Thermal expansion coefficients of La Sr CrO and reduced La Sr CrO were measured using a push-rod type dilatometer in the temperature range from 100 to 873 K. The thermal expansion coefficient increased and the temperature of structural transition from orthorhombic to rhombohedral decreased with the increase of Sr content. Magnetic transition temperature decreased with the decrease of Cr content in La Sr CrO . The doping effect of Sr in La Sr CrO on the thermal expansion was discussed using molecular dynamics simulation. © 2001 Published by Elsevier Science B.V. 1-x x 3 1-x x 3-δ 1-x x 3-δ 1-x x 3 3+

Thermal expansion coefficients of perovskite oxides LaMO and La Sr MO with different size of B-site ions were measured, and the doping effect to the phase transition from orthorhombic to rhombohedral structure was discussed in terms of the size of the B-site ions and the tolerance factor of the perovskites. The transition temperature from orthorhombic to rhombohedral structure of LaGaO rose with Mg doping, but it did not change significantly in the case of Sr doping. The thermal expansion coefficient of LaScO , and LaInO and LaAlO showed no thermal expansion anomaly from orthorhombic to rhombohedral structure. The transition temperature from orthorhombic to rhombohedral structure for LaMO and La Sr MO with different size of B-site ions linearly decreased with the tolerance factor, indicating that the perovskite with a small tolerance factor is distorted, resul ting in the higher transition temperature. The perovskite with a small tolerance factor was shown to be distorted using the pair correlation function of oxygen-oxygen obtained by molecular dynamics calculation. © 2001 Elsevier Science B.V. All rights reserved. 3 0.9 0.1 3 3 3 3 3 3 0.9 0.1 3

A new method to measure heat flux and thermal expansion simultaneously with a temperature resolution of milli-Kelvin is presented to observe the multistage transitions. At least six thermal anomalies are observed between 402 and 403 K in BaTiO simultaneously in heat flux and thermal expansion in the cooling process. The correspondence of the anomalies observed in the two physical properties is excellent. 3

Thermal expansion coefficients of LaCrO and Al O were measured using a push-rod type dilatometer in the temperature range from 100 to 873 K. The error of the measurement depending on the position of the thermocouple in the dilatometer was also investigated. The thermal expansion coefficient of Al O in the temperature range from 100 to 873 K generally agreed with the literature value. Anomalies in the thermal expansion coefficient were observed clearly at 283 and 528.5 K in LaCrO . The first anomaly is a volume expansion due to the transition from an anti-ferromagnetic to a paramagnetic state, the second one is a volume shrinkage due to the transition from an orthorhombic to a rhombohedral structure. The thermal expansion coefficient measured using the thermocouple on the reference side was about 1% higher than that using the thermocouple attached on the sample. The error of the transition temperature due to the position of the thermocouple was also investigated. (C) 2000 Elsevier Science B.V. 3 2 3 2 3 3

The thermal expansion coefficients of CeO and Gd-doped ceria were measured in the range from 100 to 873 K and those of reduced ceria were measured from 100 to 323 K. The thermal expansion coefficient of Ce Gd O became large with increasing the dopant content, x. The thermal expansion coefficient of reduced ceria became large with increasing the vacancy content of oxygen. These increases of the thermal expansion coefficients result from weakening binding energy due to the increase of oxygen vacancy. The thermal expansion coefficients of CeO and Gd-doped ceria were calculated theoretically and they were in good agreement with experimental ones except for the higher temperature range. 2 1-x x 2-x/2 2

Oxygen diffusion and the microscopic structure of ceria-based solid electrolytes Ce M O (M = La, Gd and Y) for x values between 0.02 and 0.3 were investigated by means of the molecular dynamics simulation. The compositional dependence of lattice parameters for the three dopants was in good agreement with experimental values. The calculated oxygen diffusion coefficient of Gd-doped ceria was larger than that of La- or Y-doped ceria as the experimental data showed. The nearest neighbor distance of Ce-O decreased and that of O-O increased with increase of the dopant content in the all doped cerias. The nearest neighbor distance of M-O increased in case of La doping, while it decreased in case of Y doping and the Gd-O distance was almost the same as the Ce-O distance in the non-doped ceria in case of Gd doping. The oxygen coordination number around a dopant was about seven for all cases, suggesting that dopant ions form a M-vacancy-M cluster. Large lattice distortion was observed in La- and Y-doped ceria, where the ionic radius of the dopant ion is fairly different from `optimum radius' of dopant in ceria. The reason why the oxygen diffusion coefficient is the largest in Gd-doped ceria is mainly explained in terms of the lattice distortion. 1-x x 2-0.5x

Thermal expansion coefficients for Sr- and Mg-doped LaGaO were measured and the doping effect was discussed in terms of the content of oxygen vacancy. The thermal expansion coefficients of the oxides became large with dopant content. A large shrinkage caused by the phase transition from orthorhombic to rhombohedral for LaGaO was observed at 421 K. The shrinkage became small and broad with Sr and Mg doping. The transition temperature became higher with the Mg content in the case of Mg doping. The theoretical calculation of the thermal expansion coefficient of these oxides was also conducted and the calculated thermal expansion coefficient of LaGaO was in good agreement with the experimental one except for the temperature range of the phase transition. The larger thermal expansion coefficients due to Sr and Mg doping were ascribed to smaller binding energy in the oxides by the presence of oxygen vacancy using the theoretical calculation. 3 3 3

Ionic conductivity of perovskite-type oxides is discussed in terms of structurally related parameters. Electrical conductivity data of perovskite-type oxides, reported as oxygen ion conductors, were collected from literatures and the correlation between the electrical conductivity of these compounds and the structurally related parameters, such as tolerance factor, specific free volume and oxygen deficiency was examined. The tolerance factor and the specific free volume were both a function of ionic radius and the tolerance factor decreased with increasing the specific free volume. The optimum tolerance factor was found to be around 0.96 due to the balance between the specific free volume and the tolerance factor in order to obtain the maximum electrical conductivity for A B O -type perovskites. The optimum oxygen deficiency to obtain the maximum electrical conductivity was around 0.2. The effect of ionic size of dopant ions in A and B site on electrical conductivity was also discussed. III III 3

Oxygen diffusion in the oxygen ion conductor of gadolinia-doped ceria (CeO ) (Gd O ) was investigated by means of the molecular dynamics simulation. The atomic arrangement with Gd-Gd pairs in gadolinia-doped ceria was found to be energetically more stable and more realistic than that with isolated Gd atoms from the calculation of the enthalpy of formation and the lattice parameter. The compositional dependence of the diffusion constant was in good agreement with the experimental one obtained from the data of electrical conductivity. The Gd-O nearest neighbor distance was longer than that of Ce-O and they were decreased with the increase of the gadolinia content in an excellent agreement with an EXAFS study. The oxygen coordination number of Gd was about seven except for a very small gadolinia content, suggesting that Gd ions are apt to form a Gd -vacancy-Gd cluster. The reason why the diffusion constant at high gadolinia contents decreases was discussed in terms of short range and long range interactions. Comparison of diffusion behavior with yttria stabilized zirconia was also discussed. 2 1-x 2 3 x/2 3+ 3+

Equilibrium surface tension versus concentration curves for aqueous solutions of homologs of lysophosphatidylcholine (lysoPC) and lysophosphatidylethanolamine (lysoPE) and two analogs of lysoPC, that is, alkylphosphorylcholine and partially fluorinated lysoPC were measured by the Wilhelmy plate method using a ground-glass plate. From these measurements the critical micelle concentration (cmc), the molecular area in saturated adsorption, the standard chemical potential of adsorption from the infinitely dilute solution to the saturated adsorption surface, and the standard chemical potential of micellization were obtained for each lipid. Further, the measurements of the free energy of formation of black film, the steady-state fluorescence anisotropy in the non-polar region of black film and the rate of growth of black film were performed separately for single foam films of the above lipids, together with the measurement of foam stability. By comparing these surface chemical properties among the respective lysophospholipids, the difference in foam stability between lysoPC and lysoPE is discussed in terms of these static and dynamic properties of solution surfaces and single foam films.

Aggregation numbers and shapes of 1-palmitoyl-sn-glycero-3-phosphocholine(LPPC) and 1-lauroyl-sn-glycero-3-phosphoethanolamine(LLPE) micelles have been investigated at 35 °C by static and dynamic light scattering method. The average aggregation number of LPPC micelle is 139. The LLPE micelle is rod-like shape, and grows with increasing concentration. At 5.87 mg cm⁻³ micelle concentration, apparent aggregation number of LLPE is 902 and average length of rigid rod is estimated to be 45–57 nm.