scholarly journals Effect of Cryostructuring Treatment on Some Properties of Xanthan and Karaya Cryogels for Food Applications

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2788
Author(s):  
Jonathan Coria-Hernández ◽  
Rosalía Meléndez-Pérez ◽  
Abraham Méndez-Albores ◽  
José Luis Arjona-Román
Keyword(s):  
Food Preservation ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Indirect Contact ◽  
Freeze Thaw ◽  
Food Applications ◽  
Novel Material ◽  
Scanning Electron

Cryogels are novel materials because the manufacturing process known as cryostructuring allows biopolymers to change their properties as a result of repeated controlled freeze–thaw cycles. Hydrogels of xanthan and karaya gums were evaluated after undergoing up to four controlled freeze–thaw cycles in indirect contact with liquid nitrogen (up to −150 °C) to form cryogels. Changes in structural, molecular, rheological, and thermal properties were evaluated and compared to those of their respective hydrogels. Samples were also analyzed by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR), Rotational Rheology (RR), Modulated Differential Scanning Calorimetry (MDSC) and zeta potential (ζ). In general, significant differences (p < 0.05) between the numbers of freeze–thaw cycles were found. Karaya cryogels were not stable to repeated cycles of cryostructuring such as the three-cycle xanthan cryogel, which has the best structural order (95.55%), molecular interactions, and thermal stability, which allows the generation of a novel material with improved thermal and structural properties that can be used as an alternative in food preservation.

scholarly journals Changes in myoglobin content in pork Longissimus thoracis muscle during freezing storage

2020 ◽  
Vol 11 (3) ◽  
pp. 651-668
Author(s):  
Jonathan Coria-Hernández ◽  
Rosalía Meléndez-Pérez ◽  
Abraham Méndez-Albores ◽  
José Luis Arjona-Román
Keyword(s):  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Pork Meat ◽  
Chemical Parameters ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Raw Meat ◽  
Thawing Process ◽  
Color Profile ◽  
Freezing Storage

In this study, pork Longissimus thoracis muscle was used, which was frozen in a chamber and thawed under controlled conditions. The color profile and the surface myoglobin were evaluated. A thermal analysis was performed by modulated differential scanning calorimetry (MDSC), and Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). It was found that there were important effects in myoglobin due to the freeze-thawing process in parameters such as pH, luminosity (L*), and chroma values, as well as in activation energies (Ea) and denaturation enthalpy (ΔH) between myoglobin forms. In raw meat, it was found that there was a greater proportion of deoxymyoglobin, and in frozen-thawed samples, metmyoglobin was the most abundant form, indicating that are significant effects which are correlated with the changes in tri-stimulus coordinates and with the thermal and chemical parameters in pork meat.

Exploration for Identification of Sheath-Core Fiber of Ploymer

2014 ◽  
Vol 988 ◽  
pp. 8-12
Author(s):  
Rui Tian Zhu ◽  
Peng Zhang ◽  
Feng Ming Nie
Keyword(s):  
Infrared Spectroscopy ◽  
Accurate Method ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Polymer Fiber ◽  
Reflection Method ◽  
Scanning Calorimetry ◽  
Microscopic Method ◽  
Transmission Technique ◽  
Core Fiber

In this paper, microscopic method, transmission technique and attenuated total reflection method of infrared spectroscopy and differential scanning calorimetry were investigated for analyzing the component of inner and outer layer of sheath-core polymer fiber. Results showed that transmission technique and attenuated total reflection method of infrared spectroscopy was a quick and accurate method for identification of sheath-core fiber of fiber.

scholarly journals Study of surface-enhanced infrared absorption spectroscopy (SEIRAS) of black inkjet prints using silver colloid

2017 ◽  
Vol 10 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Michal Oravec ◽  
Katsuya Miura ◽  
Michal Čeppana
Keyword(s):  
Absorption Spectroscopy ◽  
Infrared Absorption ◽  
Document Analysis ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Infrared Absorption Spectroscopy ◽  
Silver Colloid ◽  
Absorption Signal ◽  
Surface Enhanced ◽  
Scanning Electron

Abstract Only black inkjet prints were studied with regard to forensic examination of documents. We analysed twenty-one inkjet prints using surface-enhanced infrared absorption spectroscopy (SEIRAS). The present paper deals with micro-destructive document analysis based on silver nanoparticles (AgNPs) use to obtain surface enhanced ATR-FTIR (attenuated total reflection - Fourier transform infrared) spectra directly from the document. For this experiment, AgNPs in colloid form was applied. AgNPs for SEIRAS analyses were synthesised and afterwards analysed by scanning electron microscopy (SEM). The purpose of the enhancement of colloids was to improve the resolution of the absorption signal of the analysed samples from noise. In the experiment, the obtained ink ATR-FTIR spectra, with and without silver treatment, were significantly affected by the paper base.

scholarly journals Organogels for the cleaning of artifacts

2017 ◽  
Vol 89 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Maria Diletta Pianorsi ◽  
Martina Raudino ◽  
Nicole Bonelli ◽  
David Chelazzi ◽  
Rodorico Giorgi ◽  
...  
Keyword(s):  
Release Rate ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polymeric Networks ◽  
X Ray Scattering ◽  
Paper Document ◽  
New Formulation ◽  
Differential Thermogravimetry

AbstractThe cleaning of artifacts must not alter the original properties of the objects. While the use of free solvents is risky, their confinement into polymeric networks can allow the safe removal of unwanted layers from artifacts. Recently, a methyl 2-methylprop-2-enoate (MMA)-based organogel was formulated as loaded with butan-2-one (MEK), and used to remove aged varnishes from canvas paintings. However, this formulation is not enough retentive to allow its use on paper, where higher retentiveness is needed to avoid the uncontrolled spreading of MEK and dissolved materials. Here, a new PMMA-MEK gel was designed to overcome this limitation. The amount of cross-linker and monomer used in the synthesis of the gel were tuned to achieve optimal retentiveness. Differential scanning calorimetry (DSC), differential thermogravimetry (DTG), small-angle X-ray scattering (SAXS) and attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR) provided information on the solvent content, release rate, and mesoporosity of the gel as compared to the previous system. The lower solvent release rate of the new formulation allowed the safe removal of wax that jeopardized a 19th century paper document. The removal was confirmed through optical microscopy and ATR-FTIR, which also highlighted the absence of gel residues on the treated surface.

scholarly journals Application of Fluorescent Label in Polymer Nanofibers

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Lucie Zarybnicka ◽  
Radka Bacovska ◽  
Zuzana Nadvornikova ◽  
Numan Almonasy ◽  
Tomas Syrovy
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Fluorescent Probe ◽  
Solid Phase ◽  
Polyamide 6 ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Fluorescent Label ◽  
Microscope Images ◽  
Scanning Electron

The electrospinning of fluorescent probe polyamide 6 doped by 7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-on is presented as a model processing photoluminescent nanofibers. The presence of the fluorescent probe in the fiber layers was confirmed by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR); the surface nanofiber structure was described by high-resolution fluorescence microscope and scanning electron microscope images. The prepared nanofibers with the fluorescent label were further characterized by fluorescence spectroscopy, both in the solid phase and in the solution.

Polytetrafluoroethylene coating fragments during neuroendovascular therapy: An analysis of two damaged microguidewires

2021 ◽  
pp. 159101992110151
Author(s):  
Rasmus Holmboe Dahl ◽  
René Wugt Larsen ◽  
Esben Thormann ◽  
Goetz Benndorf
Keyword(s):  
Surface Coating ◽  
Polymer Coating ◽  
Silicone Oil ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Future Studies ◽  
Coating Delamination ◽  
Intravascular Devices ◽  
Exact Origin ◽  
Scanning Electron

Cerebral polymer coating embolism from intravascular devices represents a potentially serious complication to endovascular therapy (EVT). We report two cases of neuroendovascular treatment where filamentous polymer fragments were noted possibly due to damage of the surface coating during manipulation and backloading of microguidewires. As the exact origin of the debris was initially not known, microguidewires and fragments were examined with light microscopy, stereomicroscopy, scanning electron microscopy and attenuated-total-reflection Fourier transform infrared spectroscopy. Fragments consisted of polytetrafluoroethylene and silicone oil stemming from the proximal shaft of a standard microguidewire. To our knowledge, this is the first report of polytetrafluoroethylene coating fragments created during EVT. Future studies should assess the mechanism of polymer coating delamination and its potential consequences during EVT including inadvertent fragment migration into the cerebral circulation.

scholarly journals Pengamatan Surface Plasmon Resonance pada ZnO Nanorods dengan Menggunakan Konfigurasi Prisma/Au/ZnO

2020 ◽  
Vol 23 (1) ◽  
pp. 27
Author(s):  
Rina Dewi Mayasari ◽  
Ajeng Novita Sari ◽  
Aditya Eka Mulyono ◽  
Agus Setyo Budi ◽  
Ratno Nuryadi
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Zno Nanorods ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
X Ray Diffraction ◽  
X Ray ◽  
20 Nm ◽  
Scanning Electron

Pengamatan fenomena surface plasmon resonance (SPR) telah berhasil dilakukan pada ZnO nanorods yang ditumbuhkan di atas lapisan tipis emas. Sistem SPR menggunakan konfigurasi Kretschmann termodifikasi dimana permukaan prisma dideposisi dengan lapisan tipis emas dan ZnO nanorods (prisma/Au/ZnO). Penumbuhan ZnO nanorods menggunakan metode hidrotermal dengan dua tahapan, yaitu pelapisan ZnO seed dan penumbuhan rods. Waktu penumbuhan divariasikan selama 5 menit, 2 jam, dan 4 jam, pada suhu 95 °C yang diikuti dengan annealing pada suhu 500 °C selama 1 jam. Struktur ZnO dikarakterisasi dengan X-ray diffraction (XRD), field emission scanning electron microscope - energy dispersive X-ray spectroscopy (FESEM-EDS), serta diamati fenomena SPR melalui grafik attenuated total reflection (ATR). Hasil karakterisasi menunjukkan bahwa ZnO nanorods (2 jam dan 4 jam) memiliki struktur kristal heksagonal dengan distribusi ukuran diameter pada rentang 20 nm – 60 nm. Fenomena SPR hanya teramati pada nanopartikel ZnO (5 menit) pada sudut SPR (θSPR) 58,2°. Fenomena SPR tidak terlihat pada ZnO nanorods (2 jam dan 4 jam) dikarenakan panjang rods melebihi 100 nm.

Fabrication of ultrafine fibrous polytetrafluoroethylene porous membranes by electrospinning

2009 ◽  
Vol 24 (9) ◽  
pp. 2755-2761 ◽  
Author(s):  
Jie Xiong ◽  
Pengfei Huo ◽  
Frank K. Ko
Keyword(s):  
Composite Nanofibers ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Poly Vinyl Alcohol ◽  
Porous Membranes ◽  
Scanning Calorimetry ◽  
Blend Ratio ◽  
Technical Parameters ◽  
Thermogravimetric Analyzer ◽  
Before And After

Poly(vinyl alcohol) (PVA) and poly(tetrafluoroethylene) (PTFE) emulsion were blended with different mass concentrations and the blended spinning solutions were electrospun into composite nanofibers. The influence of the blend ratio of PVA to PTFE and electrospinning technical parameters on the morphology and diameter of the composite nanofibers were investigated. According to the result of thermogravimetric analyzer analysis, the composite membrane was sintered at 390 °C. The membranes were then characterized by differential scanning calorimetry, attenuated total reflection-Fourier transform infrared (ATR-FTIR), and scanning electron microscopy, respectively. The mechanical properties of the membranes before and after sintering were analyzed through tensile testing. The results show that the PTFE porous membranes could be electrospun effectively, thus demonstrating their potential application as filter media.

scholarly journals Influence of ZnO, SiO2 and TiO2 on the aging process of PLA fibers produced by electrospinning method

2019 ◽  
Vol 140 (4) ◽  
pp. 1769-1778 ◽  
Author(s):  
Karolina Kosowska ◽  
Piotr Szatkowski
Keyword(s):  
Structural Changes ◽  
Uv Light ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Poly Lactic Acid ◽  
Uv Resistance ◽  
Scanning Calorimetry ◽  
Uv Aging ◽  
Electrospinning Method ◽  
Key Factor

Abstract The aim of this work was to study the effect of ceramics particles addition (SiO2, ZnO, TiO2) on the ultraviolet (UV) aging of poly(lactic acid) nonwovens fabricated using electrospinning method. The resistance to aging is a key factor for outdoor and medical applications (UV light sterilization). Nonwovens were placed in special chamber with UV light. Changes of physicochemical properties were recorded using differential scanning calorimetry and attenuated total reflection Fourier-transform infrared spectroscopy. The fibers’ morphology was studied by using scanning electron microscopy. Obtained results clearly showed that only PLA fibers with ZnO particles gained an increase in UV resistance. The paper presents a description of structural changes taking place under the influence of UV aging processes and describes the mechanisms of this process and the effect of ceramic addition on the lifetime of such materials.

scholarly journals Dyeing of Polyester and Polyamide Synthetic Fabrics with Natural Dyes Using Ecofriendly Technique

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Khaled Elnagar ◽  
Tarek Abou Elmaaty ◽  
Sally Raouf
Keyword(s):  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Natural Dyes ◽  
Colour Strength ◽  
Ozone Pretreatment ◽  
Infrared Spectrometer ◽  
Elongation Percentage ◽  
Uv Ozone ◽  
Scanning Electron ◽  
Modification Of The Surface

This work presents an ecofriendly method for dyeing synthetic fabrics with natural dyes using UV/ozone pretreatment to activate fiber and improve dyeability of polyester and nylon. Fabrics are pretreated with UV/ozone for different periods of time ranged from 5 min to 120 min. Effect of pretreatment on surface morphology was studied by scanning electron microscope (SEM). Mechanical behavior was studied by testing tensile strength and elongation percentage. Chemical modification of the surface was studied using attenuated total reflection Fourier transform infrared spectrometer (ATR-FTIR). Dyeability of the treated samples was investigated in terms of their colour strength expressed as K/s in addition to fastness to washing and light. This research showed the increment of the affinity of the studied synthetic fabrics towards curcumin and saffron natural dyes using ecofriendly technique.

Sign in / Sign up

Export Citation Format

Share Document