dynamics simulation of spin–lattice nmr relaxation in poly-l-lysine dendrimers  (Molecular Dynamics Inc)

Journal: Molecules (Basel, Switzerland)

Article Title: Comparative Analysis of Amorphous and Biodegradable Copolymers: A Molecular Dynamics Study Using a Multi-Technique Approach.

doi: 10.3390/molecules30051175

Figure Lengend Snippet: Figure 3. Derivatives of 1H NMR absorption spectra of (a) 0.5Gly/0.2Lac/0.3Cap and (b) 0.5Gly/ 0.4Lac/0.1Cap at different temperatures. The proton derivative spectra at 273 K are highly sensitive compared to the broad DSC lines (c.f. Figure 1) for both polymers, indicating the early onset of chain molecular dynamics motion in preparation for the phase transition.

Article Snippet: 1H NMR Spin-Lattice Relaxation Time (T1) Measurement at 200 MHz 1H spin-lattice relaxation times (T1) were measured at a Larmor frequency of 200 MHz using a Bruker CXP NMR spectrometer with a saturation recovery sequence.

Techniques: Sublimation

Journal: Molecules (Basel, Switzerland)

Article Title: Comparative Analysis of Amorphous and Biodegradable Copolymers: A Molecular Dynamics Study Using a Multi-Technique Approach.

doi: 10.3390/molecules30051175

Figure Lengend Snippet: Figure 5 presents the 1H spin-lattice relaxation time (T1) measurements for 0.5Gly/0.2Lac/ 0.3Cap and 0.5Gly/0.4Lac/0.1Cap as a function of temperature, plotted against β = 10−3/T K−1. The Arrhenius plots were derived from exponential fitting of proton relaxation measure- ments at 200 MHz and 9 MHz. The T1 curves reveal three distinct relaxation modes, corresponding to the proton spin system’s relaxation via methyl (-CH3), methylene (-CH2-), and complex trans–gauche isomerization motions within the amorphous phases of both copolymers. The figure also illustrates the recovery of 1H magnetization for both samples at various temperatures. An exponential recovery was observed for all measurements, con- sistent with the results of the DSC (c.f. Figure 1), implying the presence of a single type of proton spin-lattice relaxation time (T1) in both copolymers. Generally, a single-exponential pattern of spin-lattice relaxation is expected due to sufficient spin diffusion in strongly dipolar-coupled proton systems. However, in cases where the proton coupling system

Article Snippet: 1H NMR Spin-Lattice Relaxation Time (T1) Measurement at 200 MHz 1H spin-lattice relaxation times (T1) were measured at a Larmor frequency of 200 MHz using a Bruker CXP NMR spectrometer with a saturation recovery sequence.

Techniques: Derivative Assay, Diffusion-based Assay

Journal: Molecules (Basel, Switzerland)

Article Title: Comparative Analysis of Amorphous and Biodegradable Copolymers: A Molecular Dynamics Study Using a Multi-Technique Approach.

doi: 10.3390/molecules30051175

Figure Lengend Snippet: Figure 5. Arrhenius plots of 1H spin-lattice relaxation times measurements at 200 MHz and 9 MHz for 0.5Gly/0.2Lac/0.3Cap and 0.5Gly/0.4Lac/0.1Cap. 1H experimental data fitted using the BPP model as indicated by solid lines. The experiments conducted from the low to high temperatures and the glass phase transition Tg indicated by the vertical dashed lines (according to DSC, c.f. Figure 1).

Article Snippet: 1H NMR Spin-Lattice Relaxation Time (T1) Measurement at 200 MHz 1H spin-lattice relaxation times (T1) were measured at a Larmor frequency of 200 MHz using a Bruker CXP NMR spectrometer with a saturation recovery sequence.

Techniques: Sublimation

Journal: Small (Weinheim an Der Bergstrasse, Germany)

Article Title: A Super‐Ionic Solid‐State Block Copolymer Electrolyte

doi: 10.1002/smll.202404297

Figure Lengend Snippet: Ion diffusion coefficients determined by PFG‐NMR. Diffusion coefficients ( D ) of the fast component and their activation energies ( E a ), Li + transference numbers ( t Li+ ), and estimated limiting conductivity (σ lim,90 °C ) assuming full salt dissociation. All data at 90 °C after annealing.

Article Snippet: NMR spin relaxation and diffusion measurements were conducted on a 400 MHz spectrometer (Avance III HD, Bruker, Rheinstetten, Germany) with a static field of 9.39 T with a broadband probe head with gradient coils (“Diff BBFO”, Bruker).

Techniques: Diffusion-based Assay, Activation Assay