Nonionic Short-Chain Fluorinated Surfactants in the Fatliquoring of Chrome-Tanned Goat Skin

2020 ◽  
Vol 115 (7) ◽  
pp. 255-262
Author(s):  
Yichao Shen ◽  
Yong Jin ◽  
Shuangquan Lai ◽  
Liangjie Shi ◽  
Yutang Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Repellency ◽  
Short Chain ◽  
Fiber Morphology ◽  
Leather Industry ◽  
Fluorinated Surfactants ◽  
Surface Activities ◽  
Goat Skin ◽  
Measurement Results ◽  
Almost All

Surfactants as essential auxiliaries are used in almost all chemical processes in leather production. In this work, a series of nonionic short-chain fluorinated surfactants (Fn-Fn, where n = 2, 4, or 6) were successfully prepared and used as fatliquoring auxiliaries in the fatliquoring process of chrome-tanned goat skin. The chemical structure of these nonionic short-chain fluorinated surfactants was characterized by FTIR and the molecular weight was determined by GPC. The surface tension measurement results revealed that these three fluorinated surfactants showed excellent surface activities. The effect of type and dosage of Fn-Fn as well as fatliquoring temperature on fatliquoring properties of chrome-tanned goat skin were estimated by the softness and physical mechanical properties characteristic of resultant leather. The results revealed that the leather treated with 1 wt% F4-F4 at the fatliquoring temperature of 40oC showed the best overall performance, whose softness and physical mechanical properties were improved significantly. Moreover, the collagen fiber morphology and waterproof performance of leather treated with Fn-Fn were also investigated which showed that the addition of Fn-Fn in the fatliquoring process could promote the loosening of collagen fibers while effectively enhancing the water repellency of the leather surface. Therefore, such types of nonionic short-chain fluorinated surfactants are promising to be as desired fatliquoring auxiliaries in the leather industry.

scholarly journals Electrospun PCL Patches with Controlled Fiber Morphology and Mechanical Performance for Skin Moisturization via Long-Term Release of Hemp Oil for Atopic Dermatitis

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Sara Metwally ◽  
Daniel P. Ura ◽  
Zuzanna J. Krysiak ◽  
Łukasz Kaniuk ◽  
Piotr K. Szewczyk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atopic Dermatitis ◽  
Mechanical Performance ◽  
Antibacterial Properties ◽  
Skin Condition ◽  
Fiber Morphology ◽  
Suitable Material ◽  
Hemp Oil ◽  
Skin Moisture

Atopic dermatitis (AD) is a chronic, inflammatory skin condition, caused by wide genetic, environmental, or immunologic factors. AD is very common in children but can occur at any age. The lack of long-term treatments forces the development of new strategies for skin regeneration. Polycaprolactone (PCL) is a well-developed, tissue-compatible biomaterial showing also good mechanical properties. In our study, we designed the electrospun PCL patches with controlled architecture and topography for long-term release in time. Hemp oil shows anti-inflammatory and antibacterial properties, increasing also the skin moisture without clogging the pores. It can be used as an alternative cure for patients that do not respond to traditional treatments. In the study, we tested the mechanical properties of PCL fibers, and the hemp oil spreading together with the release in time measured on skin model and human skin. The PCL membranes are suitable material as patches or bandages, characterized by good mechanical properties and high permeability. Importantly, PCL patches showed release of hemp oil up to 55% within 6 h, increasing also the skin moisture up to 25%. Our results confirmed that electrospun PCL patches are great material as oil carriers indicating a high potential to be used as skin patches for AD skin treatment.

scholarly journals Transient cell stiffening triggered by magnetic nanoparticle exposure

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jose E. Perez ◽  
Florian Fage ◽  
David Pereira ◽  
Ali Abou-Hassan ◽  
Sophie Asnacios ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Early Time ◽  
Population Level ◽  
Short Time Scale ◽  
Initial Contact ◽  
Almost All ◽  
The Impact ◽  
Stiffening Effect

Abstract Background The interactions between nanoparticles and the biological environment have long been studied, with toxicological assays being the most common experimental route. In parallel, recent growing evidence has brought into light the important role that cell mechanics play in numerous cell biological processes. However, despite the prevalence of nanotechnology applications in biology, and in particular the increased use of magnetic nanoparticles for cell therapy and imaging, the impact of nanoparticles on the cells’ mechanical properties remains poorly understood. Results Here, we used a parallel plate rheometer to measure the impact of magnetic nanoparticles on the viscoelastic modulus G*(f) of individual cells. We show how the active uptake of nanoparticles translates into cell stiffening in a short time scale (< 30 min), at the single cell level. The cell stiffening effect is however less marked at the cell population level, when the cells are pre-labeled under a longer incubation time (2 h) with nanoparticles. 24 h later, the stiffening effect is no more present. Imaging of the nanoparticle uptake reveals almost immediate (within minutes) nanoparticle aggregation at the cell membrane, triggering early endocytosis, whereas nanoparticles are almost all confined in late or lysosomal endosomes after 2 h of uptake. Remarkably, this correlates well with the imaging of the actin cytoskeleton, with actin bundling being highly prevalent at early time points into the exposure to the nanoparticles, an effect that renormalizes after longer periods. Conclusions Overall, this work evidences that magnetic nanoparticle internalization, coupled to cytoskeleton remodeling, contributes to a change in the cell mechanical properties within minutes of their initial contact, leading to an increase in cell rigidity. This effect appears to be transient, reduced after hours and disappearing 24 h after the internalization has taken place.

scholarly journals Utilization of Leather Waste Fibers in Polymer Matrix Composites Based on Acrylonitrile-Butadiene Rubber

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 117
Author(s):  
Le Thuy Hang ◽  
Do Quoc Viet ◽  
Nguyen Pham Duy Linh ◽  
Vu Anh Doan ◽  
Hai-Linh Thi Dang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polymer Matrix Composites ◽  
Waste Product ◽  
Dynamic Mechanical Properties ◽  
Hammer Mill ◽  
Butadiene Rubber ◽  
Matrix Composites ◽  
Leather Industry ◽  
Tear Strength

In this study, we present the fabrication of nitrile butadiene rubber/waste leather fiber (NBR/WLF) composites with different weight percentages of WLF and NBR (0/100, 20/80, 30/70, 40/60, 50/50, 60/40 wt/wt). WLF was prepared by cutting the scrap leathers from the waste product of the Vietnamese leather industry. Subsequently, in order to make the short fibers, it was mixed by a hammer mill. The characteristics of WLF/NBR composites such as mechanical properties (tensile strength, tear strength, hardness), dynamic mechanical properties, toluene absorption, and morphology were carefully evaluated. As a result, the tensile strength and tear strength become larger with increasing WLF content from 0 to 50 wt% and they decrease when further increasing WLF content. The highest tensile strength of 12.5 MPa and tear strength of 72.47 N/mm were achieved with the WLF/NBR ratio of 50/50 wt%. Both hardness and resistance of the developed materials with toluene increased with increasing WLF content. The SEM results showed a good adhesion of NBR matrix and the WLF. The increasing of storage modulus (E’) in comparison with raw NBR showed good compatibility between WLF and NBR matrix. This research showed that the recycled material from waste leather and NBR was successfully prepared and has great potential for manufacturing products such as floor covering courts and playgrounds, etc.

scholarly journals Application of the plasticity characteristic determined by the indentation technique for evaluation of mechanical properties of coatings: I. specific features of the test method procedure

2004 ◽  
Vol 36 (1) ◽  
pp. 27-41 ◽  
Author(s):  
A.V. Byakova ◽  
Yu.V. Milman ◽  
A.A. Vlasov
Keyword(s):  
Mechanical Properties ◽  
Indentation Load ◽  
Test Method ◽  
Simplified Model ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Modified Model ◽  
Plasticity Characteristic ◽  
Measurement Results ◽  
Hardness Values

Specific features of the test method procedure capable for determining the plasticity characteristic dH by indentation of inhomogeneous coatings affected by residual stress was clarified. When the value of the plasticity characteristic for coating was found to be as great as dH > 0.5 a simplified model was found to be reasonably adequate, while a modified model assumed compressibility of the deformation core beneath indentation. The advantage of the modified approach compared to the simplified one was grounded experimentally only if the elastic deformation for coating becomes greater than ?e ? 3.5%, resulting in the decrease of plasticity characteristic dH < 0.5. To overcome non accuracy caused by the effect of the scale factor on measurement results a comparison of different coatings was suggested using stabilized values of the plasticity characteristic dH determined under loads higher than critical, P ? Pc, ensuring week dependence of micro hardness values on the indentation load.

scholarly journals Molecular and Mechanobiological Pathways Related to the Physiopathology of FPLD2

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1947
Author(s):  
Alice-Anaïs Varlet ◽  
Emmanuèle Helfer ◽  
Catherine Badens
Keyword(s):  
Mechanical Properties ◽  
Signaling Pathways ◽  
Metabolic Disorders ◽  
Lamin A ◽  
Partial Lipodystrophy ◽  
Familial Partial Lipodystrophy ◽  
Atherosclerotic Cardiovascular Diseases ◽  
Almost All ◽  
Type V

Laminopathies are rare and heterogeneous diseases affecting one to almost all tissues, as in Progeria, and sharing certain features such as metabolic disorders and a predisposition to atherosclerotic cardiovascular diseases. These two features are the main characteristics of the adipose tissue-specific laminopathy called familial partial lipodystrophy type 2 (FPLD2). The only gene that is involved in FPLD2 physiopathology is the LMNA gene, with at least 20 mutations that are considered pathogenic. LMNA encodes the type V intermediate filament lamin A/C, which is incorporated into the lamina meshwork lining the inner membrane of the nuclear envelope. Lamin A/C is involved in the regulation of cellular mechanical properties through the control of nuclear rigidity and deformability, gene modulation and chromatin organization. While recent studies have described new potential signaling pathways dependent on lamin A/C and associated with FPLD2 physiopathology, the whole picture of how the syndrome develops remains unknown. In this review, we summarize the signaling pathways involving lamin A/C that are associated with the progression of FPLD2. We also explore the links between alterations of the cellular mechanical properties and FPLD2 physiopathology. Finally, we introduce potential tools based on the exploration of cellular mechanical properties that could be redirected for FPLD2 diagnosis.

scholarly journals The Delay Measurement and Analysis of Unreachable Hosts of Internet

2022 ◽  
Author(s):  
Ali Gezer
Keyword(s):  
Trip Time ◽  
Internet Control ◽  
Delay Measurement ◽  
Measurement Results ◽  
Measurement And Analysis ◽  
Control Message ◽  
Almost All ◽  
Random Behaviour ◽  
Shed Light

Delay related metrics are significant quality of service criteria for the performance evaluation of networks. Almost all delay related measurement and analysis studies take into consideration the reachable sources of Internet. However, unreachable sources might also shed light upon some problems such as worm propagation. In this study, we carry out a delay measurement study of unreachable destinations and analyse the delay dynamics of unreachable nodes. 2. Internet Control Message Protocol (ICMP) destination unreachable Internet Control Message Protocol-Destination Unreachable (ICMP T3) packets are considered for the delay measurement according to their code types which shows network un reach ability, host un reach ability, port un reach ability, etc. Measurement results show that unreachable sources exhibit totally different delay behaviour compared to reachable IP hosts. A significant part of the unreachable hosts experiences extra 3 seconds Round Trip Time (RTT) delay compared to accessible hosts mostly due to host un reach ability. It is also seen that, approximately 79% of destination un reach ability causes from host un reach ability. Obtained Hurst parameter estimation results reveal that unreachable host RTTs show lower Hurst degree compared to reachable hosts which is approximately a random behaviour. Unreachable sources exhibit totally different distributional characteristic compared to accessible ones which is best fitted with Phased Bi-Exponential distribution.

Fabrication of Composite Films Based on Chitosan and Vegetable-Tanned Collagen Fibers Crosslinked with Genipin

2021 ◽  
Vol 116 (10) ◽  
Author(s):  
Jie Liu ◽  
Yanchun Liu ◽  
Eleanor M. Brown ◽  
Zhengxin Ma ◽  
Cheng-Kung Liu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Water Vapor ◽  
Composite Film ◽  
Composite Films ◽  
Value Added ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Leather Industry ◽  
Compact Structure

The leather industry generates considerable amounts of solid waste and raises many environmental concerns during its disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor permeability and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging. 

scholarly journals Electrospun Alginate Fibers: Mixing of Two Different Poly(ethylene oxide) Grades to Improve Fiber Functional Properties

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 971 ◽  
Author(s):  
Barbara Vigani ◽  
Silvia Rossi ◽  
Giulia Milanesi ◽  
Maria Bonferoni ◽  
Giuseppina Sandri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ethylene Oxide ◽  
Electrospinning Process ◽  
Mechanical Resistance ◽  
Fiber Morphology ◽  
Chain Entanglement ◽  
Poly Ethylene Oxide ◽  
Alginate Fibers ◽  
Poly Ethylene ◽  
Morphology And Mechanical Properties

The aim of the present work was to investigate how the molecular weight (MW) of poly(ethylene oxide) (PEO), a synthetic polymer able to improve alginate (ALG) electrospinnability, could affect ALG-based fiber morphology and mechanical properties. Two PEO grades, having different MWs (high, h-PEO, and low, l-PEO) were blended with ALG: the concentrations of both PEOs in each mixture were defined so that each h-PEO/l-PEO combination would show the same viscosity at high shear rate. Seven ALG/h-PEO/l-PEO mixtures were prepared and characterized in terms of viscoelasticity and conductivity and, for each mixture, a complex parameter rH/rL was calculated to better identify which of the two PEO grades prevails over the other in terms of exceeding the critical entanglement concentration. Thereafter, each mixture was electrospun by varying the process parameters; the fiber morphology and mechanical properties were evaluated. Finally, viscoelastic measurements were performed to verify the formation of intermolecular hydrogen bonds between the two PEO grades and ALG. rH/rL has been proved to be the parameter that better explains the effect of the electrospinning conditions on fiber dimension. The addition of a small amount of h-PEO to l-PEO was responsible for a significant increase in fiber mechanical resistance, without affecting the nano-scale fiber size. Moreover, the mixing of h-PEO and l-PEO improved the interaction with ALG, resulting in an increase in chain entanglement degree that is functional in the electrospinning process.

Influence of Morphology on Mechanical Properties under the Combined Use of SEBS and EOr as Elastomer in PP/Elastomer/Filler Ternary Composites

2011 ◽  
Vol 19 (9) ◽  
pp. 725-732
Author(s):  
Shigeki Hikasa ◽  
Kazuya Nagata ◽  
Yoshinobu Nakamura
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Triblock Copolymer ◽  
Continuous Phase ◽  
Dispersed Phase ◽  
Impact Properties ◽  
Combined Use ◽  
Poly Ethylene ◽  
Almost All ◽  
The Impact

The influences of combined elastomers on impact properties and morphology of polypropylene (PP)/elastomer/CaCO3 ternary composites were investigated. In the case that polystyrene- block-poly(ethylene-butene)- block-polystyrene triblock copolymer (SEBS) and poly(ethylene- co-octene) (EOR) were used as elastomers, a sea-island structure consisting of EOR dispersed phase and SEBS continuous phase was formed. The elastomer and the CaCO3 particles were separately dispersed in PP matrix. In the case that carboxylated SEBS (C-SEBS) and EOR were used, the C-SEBS particles were dispersed in the EOR particles. Almost all of the CaCO3 particles were dispersed in the PP matrix, although some of the CaCO3 particles were dispersed in the C-SEBS/EOR combined particles. Impact strength improved with an increase of incorporated CaCO3 particles. The effect of elastomer on the impact strength was SEBS ≥ SEBS/EOR > EOR = C-SEBS/EOR > C-SEBS. The morphology formed by elastomer and CaCO3 particles strongly affected the impact properties of the ternary composites.

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