Development of a super-high magnetic-field gradient pulsed NMR probe and its applications to polymer condensed systems

超高磁场梯度脉冲核磁共振探针的研制及其在聚合物凝聚体系中的应用

• 批准号: 07555297
• 负责人: NOSE Takuhei
• 金额: $ 6.72万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555297/
• 关键词: Pulsed-field gradient spin-echo; NMR; Diffusion; Polymer condensed systems

We succeeded in constructing a new NMR probe which could generate high magnetic-field gradient being up to 2000G/cm. Specifications of the probe are as follows. Pulse width : 0.6ms-20ms ; pulse interval : 600ms ; pulse sequence : Hahn echo method ; diameter of sample tube : 5mm. Applying the probe for studies of complex polymer systems, we obtained the following results : (1) Self-diffusion coefficients of poly (ethylene glycol) (PEG) dissolved in swollen. poly (N,N-dimethylacrylamide) gels were measured. It was found that the diffusion coefficient exponentially decreases with increasing the chain dimension of PEG scaled by the hydrodynamic screening length of the matrix gel. (2) The self-diffusion coefficient of PEG-(oleyl ether) dissolved incopolymer solutions of N,N-dimethylacrylamide/ (stearyl itaconic acid) showed that the translation diffusion is slowed down, while the segmental motion of the PEG is not affected, by micellar formation of the probe polymer with the matrix polymer. (3) The self-diffusion coefficient of poly (diethylsiloxane) in bulk is discontinuously decreasedat the transition from a liquid crystalline meso-phase to isotropic phase with increasing temperature. (4) Diblock copolymer solutions of polystirene/poly (dimethylsiloxane) in selective poor solvents were found to exhibit complex phase behavior by means of static and dynamic light scattering. Combining self-diffusion measurements with dynamic light scattering will promisingly provide important information for the phase behavior because there occurs intermolecular associations in the solutions, although the measurements are about to be carried out.

我们成功地构建了一种新的核磁共振探针，它可以产生高达2000 G/cm的高磁场梯度。探头规格如下。脉冲宽度：0.6ms-20 ms，脉冲间隔：600 ms，脉冲序列：Hahn回波法，样品管直径：5 mm。将该探针应用于复杂高分子体系的研究，得到了以下结果：（1）聚乙二醇（PEG）在溶胀状态下的自扩散系数。聚（N，N-二甲基丙烯酰胺）凝胶的测量。结果表明，随着PEG分子链尺寸的增加，扩散系数呈指数下降趋势，而PEG分子链尺寸的增加与凝胶基质的水动力屏蔽长度成正比。(2)PEG-（油基醚）溶解的N，N-二甲基丙烯酰胺/（硬脂基衣康酸）的共聚物溶液的自扩散系数表明，通过探针聚合物与基质聚合物的胶束形成，平移扩散减慢，而PEG的链段运动不受影响。(3)聚二乙基硅氧烷的自扩散系数随温度的升高从液晶中间相向各向同性相转变时不连续地减小。(4)用静态和动态光散射方法研究了聚苯乙烯/聚二甲基硅氧烷嵌段共聚物在选择性不良溶剂中的溶液的相行为。结合自扩散测量与动态光散射将有望提供重要的信息相行为，因为有发生在溶液中的分子间缔合，虽然即将进行的测量。

项目成果

S.Matsukawa: "A Study of Self-Diffusion of Molecules in Polymer Gel by Pulsed-Gradient Spin-Echo ^1H NMR" Macromolecules. 29. 7136-7140 (1996)

S.Matsukawa：“通过脉冲梯度自旋回波 ^1H NMR 研究聚合物凝胶中分子的自扩散”大分子。

I.Ando: "Structures and Dynamics of Polymer Gels Observed by 1H NMR Imaging and 1H PGSE NMR Methods" The Wiley Polymer Networks Group Review. 1(in press).

I.Ando：“通过 1H NMR 成像和 1H PGSE NMR 方法观察到的聚合物凝胶的结构和动力学”Wiley Polymer Networks Group Review。

T.Nose: "Interfacial Tension of a Demixed A/B Polymer Blend with A-B Diblock Copolymer near the Critical Point" Macromol. Symp.(1996)

T.Nose：“在临界点附近具有 A-B 二嵌段共聚物的分层 A/B 聚合物共混物的界面张力”Macromol。

I.Ando: "Structures and Dynamics of polymer Gels Observed by ^1H NMR Imaging and ^1H PGSE NMR Methods" The Wiley Polymer Networks Group Review. 1,(in press).

I.Ando：“通过^1H NMR 成像和^1H PGSE NMR 方法观察到的聚合物凝胶的结构和动力学”Wiley Polymer Networks Group Review。

S.Matsukawa: "A Study of Self-Diffusion of Molecules in Polymer Gel by Pulsed-Gradient Spin-Echo IH NMR" Macromolecules. 29. 7136-7140 (1996)

S.Matsukawa：“通过脉冲梯度自旋回波 1H NMR 研究聚合物凝胶中分子的自扩散”大分子。