Evaluation of Cinnamon by Solid-State NMR Employing Relaxometry

To evaluate the molecular dynamics and the molecular regions presented in the cinnamon types it was chosen to evaluate them without any treatment, and for that it was used low-field nuclear magnetic resonance (NMR) through the pulse sequence such as MSE-FID, an NMR sequence in the time domain, and from the longitudinal relaxation time (with a time constant T1), employing the inversion-recovery pulse sequence. The low-field NMR results indicate that the techniques chosen were a very good alternative to evaluate these types of samples food and their structural organization according to their constituents. The molecular mobility is different.

Thermal and Crystallization Behavior of PLA/PLLA-Grafting Cellulose Nanocrystal

PLLA-modified cellulose nanocrystals (CNC) were produced from commercial CNC by tin-catalyzed polymerization of lactide in presence of CNC. FTIR spectroscopy demonstrated that the result of the reaction produced the grafting of PLLA chains onto CNC surface (CNC-g-PLLA). Films of poly(lactic acid) (PLA) and PLA/CNC nanocomposites (with non-modified CNC and CNC-g-PLLA) containing 0.5% and 5% (w/w) of the nanofillers were prepared by casting in chloroform solution and the crystallization behavior and thermal properties investigated. All nano-composites had similar thermal stability when analyzed by TGA analyses under an inert nitrogen atmosphere. Addition of both types of CNC influenced crystallization, the higher crystallization rate being observed for 5% (w/w) CNC. Nanocomposites with 5% (w/w) CNC-g-PLLA had the strain resistance of PLA improved in the rubbery state. PLLA-modification of CNC surface increased the crystallization of PLA in PLA/CNC nanocomposites and improved the rigidity at temperatures above the glass transition, properties which are desirable for hot drinking application.

Morphological, Biological and Physicochemical Evaluation of ABS-Based Systems Containing Graphene Obtained by 3D Printing via Solution

3D printing is a valuable resource that allows flexibility in the production of objects based on a virtual file. When it is combined with nanotechnology, new features can be added to existing materials. Thus, form and function can be associated to achieve a specific goal, such as the development of support structures for cell growth applicable to systems aiding tissue regeneration. Based on this rationale, the present work proposes a system composed of ABS and graphene nanoparticles solubilized in acetone to be 3D impressed using solvent casting technique. Our main goal was to develop a biocompatible and non-degradable material that fully makes use of the design versatility of 3D printing, to enable new practical employments in the future, for example in the medical field. In this study, different characterization techniques were used—such as microscopy, TGA, DSC, and others—to understand the features and properties of the material obtained, as well as the viability of its use and diffusion. Moreover, the artifacts impressed proved to be non-cytotoxic and promoted cellular adhesion to the cellular lineage of fibroblasts L929. In sum, we believe that the technology described in this article has the potential to serve as a basis for the development of future biocompatible materials that take advantage of their three-dimensional design to perform their functions.

Characterization of Flaxseed Oil for Nuclear Magnetic Resonance and Its Encapsulation

Flaxseed (Linum usitatissimum L.) is one of the oldest crops known by humans and it has been used in numerous applications, such as in the textile industry, feed formulation, fertilizers, and paper industry. However, nowadays these seeds have won an important highlight for human consumption due to their active ingredients that make them an excellent functional food. Thus, this study aimed to extract flaxseed oil, an oil rich in omega 3 and 6, characterize it by using nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) and then encapsulate this oil in polycaprolactone (PCL) on the micro scale, using the nanoprecipitation technique and subsequently freeze-drying. To determine the mean diameter, the dynamic light scattering technique (DLS) was used, and to verify whether there was encapsulation, the pulse sequence MSE-FID, an NMR sequence in the time domain, was also used. In addition to the previously mentioned techniques, X-ray diffraction (XRD) was also employed. Flaxseed flour was also analyzed by time-domain NMR and FTIR. The results obtained by NMR show that the oil consists of fatty acid esters in the form of triglycerides in which there is the presence of esters of α-linolenic and linoleic acids, respectively ALA and LA, according to the literature. Regarding the material after encapsulation, it presented a mean diameter of 445.2 ± 41 nm and PDI of 0.674 ± 0.064, therefore classified as microparticles. Finally, using the sequence MSE-FID and the FTIR, it can be concluded that there has been the microencapsulation of flaxseed oil in the particles formed.

Organically-Expanded Graphite/Octadecylamine: Structural, Thermal and Relaxation Evaluation

Natural graphite was chemically modified by an acid mixture (H2SO4/HNO3, 4:1) using sonication. The resulting material was then expanded with octadecylamine by the dispersion method. The sample was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG), wide-angle X-ray diffraction (WAXD) and relaxometry—low-field nuclear magnetic resonance (LFNMR). The SEM images revealed the expansion of the graphite layers. The presence of CH absorption was detected in the infrared spectrum of the expanded sample. The WAXD showed an additional diffraction peak at lower 2θ angle, indicating that intercalation of octadecylamine was successful. The thermogravimetry curve revealed three degradation steps. Two of them could be attributed to different structures (delaminated and exfoliated). The relaxometry showed that the relaxation time was dependon the frequency and the curve of the graphite/octadecylamine presented two peaks—approximately before 106 Hz and after 107 Hz. The results permitted inferring that organically modified graphite was achieved.