scholarly journals Smart Hydrogel Bilayers Prepared by Irradiation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1753
Author(s):  
Weixian Huo ◽  
Heng An ◽  
Shuquan Chang ◽  
Shengsheng Yang ◽  
Yin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Antibacterial Properties ◽  
Cross Linking ◽  
Temperature Sensitive ◽  
Temperature Changes ◽  
Smart Hydrogel ◽  
Isopropyl Acrylamide ◽  
Hydrogel Synthesis ◽  
Potential Applications

Environment-responsive hydrogel actuators have attracted tremendous attention due to their intriguing properties. Gamma radiation has been considered as a green cross-linking process for hydrogel synthesis, as toxic cross-linking agents and initiators were not required. In this work, chitosan/agar/P(N-isopropyl acrylamide-co-acrylamide) (CS/agar/P(NIPAM-co-AM)) and CS/agar/Montmorillonite (MMT)/PNIPAM temperature-sensitive hydrogel bilayers were synthesized via gamma radiation at room temperature. The mechanical properties and temperature sensitivity of hydrogels under different agar content and irradiation doses were explored. The enhancement of the mechanical properties of the composite hydrogel can be attributed to the presence of agar and MMT. Due to the different temperature sensitivities provided by the two layers of hydrogel, they can move autonomously and act as a flexible gripper as the temperature changes. Thanks to the antibacterial properties of the hydrogel, their storage time and service life may be improved. The as prepared hydrogel bilayers have potential applications in control devices, soft robots, artificial muscles and other fields.

scholarly journals Alginate/Poly(γ-glutamic Acid) Base Biocompatible Gel for Bone Tissue Engineering

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wing P. Chan ◽  
Fu-Chen Kung ◽  
Yu-Lin Kuo ◽  
Ming-Chen Yang ◽  
Wen-Fu Thomas Lai
Keyword(s):  
Mechanical Properties ◽  
Glutamic Acid ◽  
Blood Compatibility ◽  
Cross Linking ◽  
Temperature Sensitive ◽  
Minor Effect ◽  
Acid Base ◽  
A Minor ◽  
Sodium Form ◽  
Alginate Matrix

A technique for synthesizing biocompatible hydrogels by cross-linking calcium-form poly(γ-glutamic acid), alginate sodium, and Pluronic F-127 was created, in which alginate can be cross-linked by Ca2+from Ca–γ-PGA directly andγ-PGA molecules introduced into the alginate matrix to provide pH sensitivity and hemostasis. Mechanical properties, swelling behavior, and blood compatibility were investigated for each hydrogel compared with alginate and forγ-PGA hydrogel with the sodium form only. Adding F-127 improves mechanical properties efficiently and influences the temperature-sensitive swelling of the hydrogels but also has a minor effect on pH-sensitive swelling and promotes anticoagulation. MG-63 cells were used to test biocompatibility. Gelation occurred gradually through change in the elastic modulus as the release of calcium ions increased over time and caused ionic cross-linking, which promotes the elasticity of gel. In addition, the growth of MG-63 cells in the gel reflected nontoxicity. These results showed that this biocompatible scaffold has potential for application in bone materials.

scholarly journals Safely Dissolvable and Healable Active Packaging Films Based on Alginate and Pectin

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1594 ◽  
Author(s):  
Maziyar Makaremi ◽  
Hosnieh Yousefi ◽  
Giuseppe Cavallaro ◽  
Giuseppe Lazzara ◽  
Calvin Bok Sun Goh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Morphological Study ◽  
Food Packaging ◽  
Antibacterial Properties ◽  
Packaging Material ◽  
Packaging Films ◽  
E Coli ◽  
Biocomposite Films ◽  
Healing Efficiency ◽  
Potential Applications

Extensive usage of long-lasting petroleum based plastics for short-lived application such as packaging has raised concerns regarding their role in environmental pollution. In this research, we have developed active, healable, and safely dissolvable alginate-pectin based biocomposites that have potential applications in food packaging. The morphological study revealed the rough surface of these biocomposite films. Tensile properties indicated that the fabricated samples have mechanical properties in the range of commercially available packaging films while possessing excellent healing efficiency. Biocomposite films exhibited higher hydrophobicity properties compared to neat alginate films. Thermal analysis indicated that crosslinked biocomposite samples possess higher thermal stability in temperatures below 120 °C, while antibacterial analysis against E. coli and S. aureus revealed the antibacterial properties of the prepared samples against different bacteria. The fabricated biodegradable multi-functional biocomposite films possess various imperative properties, making them ideal for utilization as packaging material.

Evaluation of Gamma Radiation on NR/PHBV Blends

2013 ◽  
Vol 300-301 ◽  
pp. 1325-1329 ◽  
Author(s):  
Maneewong Chutamas ◽  
Sunthornvarabhas Jackapon ◽  
Klana Rong Sriroth
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Gamma Ray ◽  
Gamma Dose ◽  
Cross Linking ◽  
Good Adhesion ◽  
Adhesion Properties ◽  
Elongation At Break ◽  
Sem Micrograph ◽  
Radiation Technique

Natural rubber (NR) was compounded with polyhydroxybutyrate-co-hydroxyvalerate (PHBV) to improve mechanical properties for making a composite to be used in packaging applications. Gamma radiation technique was used to improve adhesion properties between these materials. The results showed that gamma radiation could induce cross-linking between NR and PHBV. The SEM micrograph illustrated the radiated NR/PHBV blends with gamma dose 5 kGy, 10 kGy and 15 kGy presenting a good adhesion at the blend interface. The investigation by FTIR, showing the appearance of small peaks at 2950 and 2997 cm-1 related to CH3 asymmetric stretching, also confirmed the cross-linking after the exposure of the NR/PHBV blend to gamma radiation. Also, the tensile results supported cross-linking between NR and PHBV. The elongation at break of NR/PHBV blend decreased when increasing dosage of gamma ray from 0 kGy to 15 kGy.

scholarly journals Advances on biodegradable zinc-silver-based alloys for biomedical applications

2021 ◽  
Vol 19 ◽  
pp. 228080002110624
Author(s):  
Ximei Xiao ◽  
Enyang Liu ◽  
Jinlong Shao ◽  
Shaohua Ge
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Human Body ◽  
Biomedical Applications ◽  
Antibacterial Properties ◽  
Research Field ◽  
Medical Applications ◽  
Secondary Surgery ◽  
Biodegradable Metals ◽  
Potential Applications

The biodegradable metals have great potential for the biomedical applications, which could be gradually degraded, absorbed, or excreted in the human body, avoiding the removal though secondary surgery. Zinc-based alloys are novel series of degradable metals for medical applications, and they are gaining lots of attention in the research field of absorbable metals. Zinc-silver (Zn-Ag) alloys show superior mechanical strength, good biodegradability, biocompatibility, and antibacterial properties, which render them to be potential candidates for biomedical applications. In this paper, we reviewed the development of Zn-Ag alloys in terms of mechanical properties, degradabilities, biocompatibilities, antibacterial properties, and potential applications in dentistry.

Effect of Gamma Radiation on Mechanical Properties of Tooth Structure

2016 ◽  
Vol 3 (3) ◽  
pp. 209-214
Author(s):  
Rania Hindi ◽  
Hala Hazzaa ◽  
Doaa El-Sharkawy
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Tooth Structure

scholarly journals A Slot-Die Technique for the Preparation of Continuous, High-Area, Chitosan-Based Thin Films

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1566
Author(s):  
Oliver J. Pemble ◽  
Maria Bardosova ◽  
Ian M. Povey ◽  
Martyn E. Pemble
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
High Volume ◽  
Mechanical Anisotropy ◽  
Diverse Range ◽  
Direction Parallel ◽  
High Area ◽  
Wide Range ◽  
Slot Die ◽  
Potential Applications

Chitosan-based films have a diverse range of potential applications but are currently limited in terms of commercial use due to a lack of methods specifically designed to produce thin films in high volumes. To address this limitation directly, hydrogels prepared from chitosan, chitosan-tetraethoxy silane, also known as tetraethyl orthosilicate (TEOS) and chitosan-glutaraldehyde have been used to prepare continuous thin films using a slot-die technique which is described in detail. By way of preliminary analysis of the resulting films for comparison purposes with films made by other methods, the mechanical strength of the films produced was assessed. It was found that as expected, the hybrid films made with TEOS and glutaraldehyde both show a higher yield strength than the films made with chitosan alone. In all cases, the mechanical properties of the films were found to compare very favorably with similar measurements reported in the literature. In order to assess the possible influence of the direction in which the hydrogel passes through the slot-die on the mechanical properties of the films, testing was performed on plain chitosan samples cut in a direction parallel to the direction of travel and perpendicular to this direction. It was found that there was no evidence of any mechanical anisotropy induced by the slot die process. The examples presented here serve to illustrate how the slot-die approach may be used to create high-volume, high-area chitosan-based films cheaply and rapidly. It is suggested that an approach of the type described here may facilitate the use of chitosan-based films for a wide range of important applications.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

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.

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