Domain sizes in heterogeneous polymers by spin diffusion using single-quantum and double-quantum dipolar filters

Complex Morphology of Melt‐Spun Nylon‐6 Fibres Investigated by1H Double‐Quantum‐Filtered NMR Spin‐Diffusion Experiments

“…Recently, spin-diffusion experiments with DQ filters were performed to determine the rigid amorphous, interface, and the mobile amorphous domain sizes in diblock copolymers. [25] The domain sizes measured by the rigid-domain filters were in good agreement with those ob- The complex morphology of high-speed melt-spun nylon-6 fibres hydrated with D 2 O was investigated using 1 H double-quantum-filtered spin-diffusion NMR experiments. The magnetisation exchange from selected crystalline domains along the fibrils and interfibrils was simulated with the help of a three-dimensional solution of a spin-diffusion equation approximated by a product of one-dimensional analytical NMR signals, which correspond to a lamellar morphology.…”

“…[25] The efficiency of the DQ filter was measured for the nylon-6 fibre drawn at DR = 3.2 and hydrated in D 2 O. The results are shown in Figure 4.…”

“…The main goal of this article is to show how a new development in the spin-diffusion methodology, [25] related to dipolar filters, can lead to a more detailed description of the complex morphology of heterogeneous polymers. The new approach adopted in this study is based on the use of a double-quantum dipolar filter that selects the initial nuclear polarisation in the crystalline domains together with a 3D analytical solution of the spin-diffusion equation.…”

Dinâmica molecular e formação de domínios em copolímeros em bloco estudados por RMN de alta e baixa resolução

“…As três transições possíveis -3/2-1/2, -1/2+1/2 e 1/23/2 têm picos bem definidos. c) Espectro de 7 Li obtido através do experimento 3.7.1-b. A linha larga é devida apenas a interação quadrupolar.…”

“…Em suma, os espectros de 7 Li carregam informações sobre o acoplamento dipolar 1 H- 7 Li o qual talvez possa ser promediado totalmente aumentando a temperatura da amostra, podendo este fato ser comprovado por experimentos 3.7.1-a como função da temperatura. A perda da intensidade da interação quadrupolar elétrica pode ser detectada da mesma maneira.…”