Surface Modification of Acid Activated Polyamide Fiber by Immobilizing Collagen

2011 ◽  
Vol 393-395 ◽  
pp. 1501-1505
Author(s):  
Xue Chuan Wang ◽  
Pei Yi Wang ◽  
Tao Tao Qiang ◽  
Long Fang Ren
Keyword(s):  
Moisture Absorption ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
Dyeing Properties ◽  
Atomic Force ◽  
Polyamide Fiber ◽  
Polyamide Fibers ◽  
Dyed Fabrics ◽  
Thermo Stability ◽  
Collagen Immobilization

Collagen was immobilized onto moderate acid activated polyamide fibers with glutaraldehyde (cross-linking agent) aimed to improve its sanitary property. The immobilization of collagen onto polyamide fiber was estimated by dyeing collagen modified fabrics with a cationic brilliant red 5GN, and determining the dyeing properties of the dyed fabrics. The modification also confirmed technically by Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and Atomic force microscope (AFM). Cationic dyeing showed brighter and more even dyeing properties of the collagen modified fabrics compared to the non-treated fabrics. From DSC results, it was found that the thermo-stability of the non-treated and collagen modified fabrics changed a lot. The morphology of different samples from SEM and AFM also approved the immobilization of collagen. The moisture absorption and hydrophilicity of the fabrics after collagen immobilization improved compared to the non-treated fabrics.

scholarly journals Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2575
Author(s):  
Smaher M. Elbayomi ◽  
Haili Wang ◽  
Tamer M. Tamer ◽  
Yezi You
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Benzoyl Group ◽  
Antioxidant Evaluation ◽  
Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

scholarly journals Synthesis and Characterization of N-Substituted Polyether-Block-Amide Copolymers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 773
Author(s):  
Jyun-Yan Ye ◽  
Kuo-Fu Peng ◽  
Yu-Ning Zhang ◽  
Szu-Yuan Huang ◽  
Mong Liang
Keyword(s):  
Titanium Isopropoxide ◽  
Decomposition Temperature ◽  
Phenyl Isocyanate ◽  
Cross Linking ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Melt Polycondensation ◽  
Structural Regularity

A series of N-substituted polyether-block-amide (PEBA-X%) copolymers were prepared by melt polycondensation of nylon-6 prepolymer and polytetramethylene ether glycol at an elevated temperature using titanium isopropoxide as a catalyst. The structure, thermal properties, and crystallinity of PEBA-X% were investigated using nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, wide angle X-ray diffraction, and thermogravimetric analysis. In general, the crystallinity, melting point, and thermal degradation temperature of PEBA-X% decreased as the incorporation of N-methyl functionalized groups increased, owing to the disruption caused to the structural regularity of the copolymer. However, in N-acetyl functionalized analogues, the crystallinity first dropped and then increased because of a new γ form arrangement that developed in the microstructure. After the cross-linking reaction of the N-methyl-substituted derivative, which has electron-donating characteristics, with poly(4,4′-methylenebis(phenyl isocyanate), the decomposition temperature of the resulting polymer significantly increased, whereas no such improvements could be observed in the case of the electro-withdrawing N-acetyl-substituted derivative, because of the incompleteness of its cross-linking reaction.

scholarly journals Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 878
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Ft Ir ◽  
Acrylate Monomers ◽  
Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

scholarly journals Chemistry of collagen cross-links: glucose-mediated covalent cross-linking of type-IV collagen in lens capsules

1993 ◽  
Vol 296 (2) ◽  
pp. 489-496 ◽  
Author(s):  
A J Bailey ◽  
T J Sims ◽  
N C Avery ◽  
C A Miles
Keyword(s):  
Type Iv Collagen ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Maximum Strain ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Type Iv ◽  
Collagen Molecules ◽  
Cross Links

The incubation of lens capsules with glucose in vitro resulted in changes in the mechanical and thermal properties of type-IV collagen consistent with increased cross-linking. Differential scanning calorimetry (d.s.c.) of fresh lens capsules showed two major peaks at melting temperatures Tm 1 and Tm 2 at approx. 54 degrees C and 90 degrees C, which can be attributed to the denaturation of the triple helix and 7S domains respectively. Glycosylation of lens capsules in vitro for 24 weeks caused an increase in Tm 1 from 54 degrees C to 61 degrees C, while non-glycosylated, control incubated capsules increased to a Tm 1 of 57 degrees C. The higher temperature required to denature the type-IV collagen after incubation in vitro suggested increased intermolecular cross-linking. Glycosylated lens capsules were more brittle than fresh samples, breaking at a maximum strain of 36.8 +/- 1.8% compared with 75.6 +/- 6.3% for the fresh samples. The stress at maximum strain (or ‘strength’) was dramatically reduced from 12.0 to 4.7 N.mm.mg-1 after glycosylation in vitro. The increased constraints within the system leading to loss of strength and increased brittleness suggested not only the presence of more cross-links but a difference in the location of these cross-links compared with the natural lysyl-aldehyde-derived cross-links. The chemical nature of the fluorescent glucose-derived cross-link following glycosylation was determined as pentosidine, at a concentration of 1 pentosidine molecule per 600 collagen molecules after 24 weeks incubation. Pentosidine was also determined in the lens capsules obtained from uncontrolled diabetics at a level of about 1 per 100 collagen molecules. The concentration of these pentosidine cross-links is far too small to account for the observed changes in the thermal and mechanical properties following incubation in vitro, clearly indicating that another as yet undefined, but apparently more important cross-linking mechanism mediated by glucose is taking place.

METHOD OF PROCESSING COLLAGEN FRESHWATER FISH TO OBTAIN A MATERIAL WITH A HIGH MOISTURE ABSORBING ABILITY

2019 ◽  
Author(s):  
Л.В. АНТИПОВА ◽  
С.А. ТИТОВ ◽  
И.В. СУХОВ
Keyword(s):  
Freshwater Fish ◽  
Moisture Absorption ◽  
Raw Materials ◽  
Silver Carp ◽  
Absorption Capacity ◽  
Personal Hygiene ◽  
Test Material ◽  
Free Access ◽  
High Moisture ◽  
Scanning Calorimetry

Исследовано взаимодействие коллагена пресноводных рыб с водой для повышения его водопоглощающей способности. Объектом исследования был вторичный продукт переработки рыбного сырья – шкуры прудовых рыб, преимущественно толстолобика. Для исследования были использованы методы термогравиметрии и дифференциальной сканирующей калориметрии. Измерения проведены на приборе синхронного термического анализа модели STA 449 F3 Jupiter. Установлено, что основная доля влаги связывается адсорбционным или осмотическим путем, а на долю капиллярной влаги приходится всего 7% массы воды, связанной образцами. Большая величина энергии связи адсорбции – 4 Дж/моль свидетельствует о способности функциональных групп коллагена к созданию гидратной оболочки, содержащей значительное количество воды. Для увеличения влагопоглощающей способности необходимо разрыхление коллагеновых волокон, что увеличивается свободный доступ влаги к фибриллам белка, увеличивающим впитывание влаги. Для эффективного разрыхления предложено выдерживать шкуры толстолобика в растворе органических кислот концентрацией 0,5%. Это позволяет добиться высокой влагоемкости, которая достигает 35–40 объемов влаги на 1 единицу массы исследуемого материала, что делает перспективным использование коллагена в качестве материала для впитывающих влагу слоев средств личной гигиены, одежды, обуви. The interaction of freshwater fish collagen with water to increase its water absorption capacity was studied. The secondary product of processing of fish raw materials – skins of pond fish, mainly silver carp, was the object of study. Methods of thermogravimetry and differential scanning calorimetry were used for the study. Measurements were carried out on the device of synchronous thermal analysis of model STA 449 F3 Jupiter. It was found that the bulk of the moisture is bound by adsorption or osmotic way, and 7% of mass of the water connected by samples fall to the share of capillary moisture. A large amount of adsorption binding energy – 4 J/mol indicates the ability of collagen functional groups to create a hydrated shell containing a significant amount of water. Loosening of collagen fibers is necessary to increase the moisture absorption capacity, which will increase the free access of moisture to the protein fibrils, increasing the absorption of moisture. It is proposed to withstand the skins of silver carp in a solution of organic acids with a concentration of 0,5% for effective loosening. This makes it possible to achieve high moisture capacity, which reaches 35–40 volumes of moisture per 1 unit mass of the test material, which makes it promising to use collagen as a material for moisture-absorbing layers of personal hygiene products, clothing, and shoes.

The role of cross-linking in the scratch resistance of organic coatings: An investigation using Atomic Force Microscopy

Wear ◽  
2019 ◽  
Vol 418-419 ◽  
pp. 151-159 ◽  
Author(s):  
Juan F. Gonzalez-Martinez ◽  
Erum Kakar ◽  
Stefan Erkselius ◽  
Nicola Rehnberg ◽  
Javier Sotres
Keyword(s):  
Atomic Force Microscopy ◽  
Scratch Resistance ◽  
Organic Coatings ◽  
Cross Linking ◽  
Force Microscopy ◽  
Atomic Force

Determination of the Physical Properties of Oil Sands Components using Scanning Probe Microscopy

2015 ◽  
Vol 1754 ◽  
pp. 69-74
Author(s):  
Ravi Gaikwad ◽  
Tinu Abraham ◽  
Aharnish Hande ◽  
Fatemeh Bakhtiari ◽  
Siddhartha Das ◽  
...  
Keyword(s):  
Oil Sands ◽  
Structural Changes ◽  
Rational Approach ◽  
Kelvin Probe ◽  
Scanning Calorimetry ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTAtomic force microscopy is employed to study the structural changes in the morphology and physical characteristics of asphaltene aggregates as a function of temperature. The exotic fractal structure obtained by evaporation-driven asphaltene aggregates shows an interesting dynamics for a large range of temperatures from 25°C to 80°C. The changes in the topography, surface potential and adhesion are unnoticeable until 70°C. However, a significant change in the dynamics and material properties is displayed in the range of 70°C - 80°C, during which the aspahltene aggregates acquire ‘liquid-like’ mobility and fuse together. This behaviour is attributed to the transition from the pure amorphous phase to a crystalline liquid phase which occurs at approximately 70°C as shown by using Differential Scanning Calorimetry (DSC). Additionally, the charged nature of asphaltenes and bitumen is also explored using kelvin probe microscopy. Such observations can lead to the development of a rational approach to the fundamental understanding of asphaltene aggregation dynamics and may help in devising novel techniques for the handling and separation of asphaltene aggregates using dielectrophoretic methods.

The Influence of Nickel Oxide Nanoparticle Dispersion on the Thermo Stability of Lubricant Oil

2019 ◽  
Vol 19 (01) ◽  
pp. 1850044
Author(s):  
K. Ramachandran ◽  
P. Navaneethakrishnan ◽  
M. Sivaraja
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Nanoparticle Dispersion ◽  
Nio Nanoparticles ◽  
Scanning Calorimetry ◽  
Lubricant Oil ◽  
Nickel Oxide Nanoparticle ◽  
Nanoparticles Dispersion ◽  
Thermo Stability

The homogeneous and substantial dispersion of nanoparticles into base fluids is vital since the final properties of any nanolubricant are estimated by their quality of stability. This paper addresses the effect of NiO nanoparticles dispersion into SN500 lubricant oil and its nonisothermal thermo stability. The dispersion of NiO nanoparticles is achieved by ultrasonication method. The thermo stability is estimated by Thermo Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). The result shows that the thermo stability of base fluid enhances up to 0.3[Formula: see text]wt.% particle concentration then it decreases due to agglomeration of dispersed nanoparticles. The findings recommend that 0.1[Formula: see text]wt.% and 0.3[Formula: see text]wt.% of NiO-nanolubricant can be used for the temperature-dependent applications up to 200∘C.

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