scholarly journals Preparation and Characterization of UV-Curable Acrylic Membranes Embedding Natural Antioxidants

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 358
Author(s):  
Ewa Rajczak ◽  
Bartosz Tylkowski ◽  
Magda Constantí ◽  
Monika Haponska ◽  
Boryana Trusheva ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Environmental Scanning Electron Microscopy ◽  
Uv Curing ◽  
Acrylic Resin ◽  
Natural Antioxidants ◽  
Inhibitory Effect ◽  
Environmental Scanning ◽  
Differential Scanning Calorimetric ◽  
Water Mixture ◽  
Uv Curable

We examine the behaviour of acrylic resin-based membranes containing natural anti-oxidants, such as Galla chinensis tea powder extract (TP) and Taiwanese green propolis (TGP), in different concentrations ranging between 5 and 20 wt %. Membrane morphology was investigated by means of Environmental Scanning Electron Microscopy (ESEM), while the UV-curing reaction was monitored by Fourier-Transform Infra-red (FTIR) spectroscopy. In most cases Thermogravimetric (TG), Differential Scanning Calorimetric (DSC) and Dynamo-mechanical Thermal (DMT) analyses showed that the desirable characteristics of the UV-cured acrylic resin are not substantially altered by the presence of the organic fillers. The release kinetics of polyphenols and flavonoids, determined in water for TP-containing membranes (ETx) and in ethanol/water mixture (7:3 v/v) for TGP-containing ones (EPx), was satisfactory, reaching a plateau after 24 h. Finally, preliminary antibacterial tests against S. epidermidis were performed on the membranes with higher additive amount and gave positive results for ET-type; on the contrary, no inhibitory effect was observed for the tested EP-type membranes.

Blending Property of Water-Based UV-Curable Polyurethane Acrylate and Epoxy Acrylate

2010 ◽  
Vol 174 ◽  
pp. 385-388
Author(s):  
Fu Qiang Chu
Keyword(s):  
Polymer Networks ◽  
Environmental Scanning Electron Microscopy ◽  
Interpenetrating Polymer Networks ◽  
Environmental Scanning ◽  
Epoxy Acrylate ◽  
Uv Curable ◽  
Polyurethane Acrylate ◽  
Water Based ◽  
Optical And Mechanical Properties ◽  
Printing Ink

Water-based UV-curable prepolymers are novel environmentally friendly materials. The blending property of two kinds of the prepolymers, water-based UV-curable polyurethane acrylate (UVPU) and water-based UV-curable epoxy acrylate (WEA), was studied in this paper. Blending compatibility, curing rate, optical and mechanical properties, and the cross-section morphology of the cured films of UVPU and WEA were investigated by Fourier transform infrared (FTIR), UV-visible spectrophotometer (UV-vis) and Environmental scanning electron microscopy (ESEM). Results indicated that the two prepolymers had good blending compatibility and high curing rate under UV radiation. The elongation at break of the cured film by WEA mixed with 20 wt% UVPU had 1.5 times increase compared to pure WEA, and the gloss increased 23% compared to pure UVPU, but the tensile strength decreased slightly. The morphology showed that the molecules of the two prepolymers polymerized each other and formed a network similar to the structure of Interpenetrating Polymer Networks (IPN). The comprehensive properties of the film were improved by blending of WEA and UVPU, and could be widely applied in the fields of coating varnish or printing ink.

Research on the Modification of Waterborne UV-Curable Polyurethane Acrylate

2013 ◽  
Vol 864-867 ◽  
pp. 698-701
Author(s):  
Jian Yun He ◽  
Yong Liu ◽  
Li Chen He ◽  
Qiang Wang
Keyword(s):  
Uv Curing ◽  
Acrylic Resin ◽  
Ethyl Acrylate ◽  
Toluene Diisocyanate ◽  
Polypropylene Glycol ◽  
Hyperbranched Polyester ◽  
Uv Curable ◽  
Polyurethane Acrylate ◽  
Overall Performance ◽  
Influent Factors

In this study, waterborne UV-curable polyurethane acrylic resin was synthesized using polypropylene glycol, toluene diisocyanate, dimethylol propionic acid and hydroxyl ethyl acrylate, and modified by hyperbranched polyester acrylate. The influent factors on hydrophilic properties and UV curing speed of the resin were discussed, and the modified resin has compared with that of unmodified resin. Results showed that the overall performance and UV curing speed of the resin modified by hyperbranched polyester was greatly enhanced, the hydrophilic property of the resin was proportional to hydrophilic group content.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Detector strategies for environmental scanning electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1296-1297
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Vacuum ◽  
Environmental Scanning Electron Microscopy ◽  
Charge Carriers ◽  
Environmental Scanning ◽  
Surface Information ◽  
X Ray ◽  
Detector Electrode ◽  
Electrons And Ions ◽  
Low Energy Electrons ◽  
Environmental Sem

Environmental SEM operate at specimen chamber pressures of ∼20 torr (2.7 kPa) allowing stabilization of liquid water at room temperature, working on rugged insulators, and generation of an environmental secondary electron (ESE) signal. All signals available in conventional high vacuum instruments are also utilized in the environmental SEM, including BSE, SE, absorbed current, CL, and X-ray. In addition, the ESEM allows utilization of the flux of charge carriers as information, providing exciting new signal modes not available to BSE imaging or to conventional high vacuum SEM.In the ESEM, at low vacuum, SE electrons are collected with a “gaseous detector”. This detector collects low energy electrons (and ions) with biased wires or plates similar to those used in early high vacuum SEM for SE detection. The detector electrode can be integrated into the first PLA or positioned at any other place resulting in a versatile system that provides a variety of surface information.

scholarly journals 616 Preventing Biofilms on BACTIGON® Coated Camstent Urinary Catheters in Patients Undergoing Elective Colorectal Surgery: A Single Centre Pilot Study

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
C Lewis-Lloyd ◽  
J Dubern ◽  
K Kalenderski ◽  
N Halliday ◽  
M Alexander ◽  
...  
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Bacterial Cells ◽  
Urinary Catheters ◽  
Elective Colorectal Surgery ◽  
Mineral Compositions ◽  
Microscopy Data ◽  
Tract Infections ◽  
Biofilm Development ◽  
Hospital Acquired

Abstract Introduction Catheter associated urinary tract infections account for 40% of hospital acquired infections. They are associated with biofilms consisting of bacterial cells enmeshed in a self-generated extracellular matrix adhering to catheter surfaces. We have developed a novel polymer family that, coated onto urinary catheters, creates a “non-stick” surface preventing biofilm development. Method Prospective cohort of elective colorectal patients recruited pre-operatively, received a standard silicone (SS) or Camstent (BACTIGON®) coated urinary catheter. After removal, catheters were cut longitudinally into 3 segments. Biomass and biomineralisation were analysed using confocal fluorescence microscopy. Data were normalised by square rooting the catheter indwelling duration. Environmental scanning electron microscopy and energy dispersive x-ray spectroscopy was performed. Results Of 40 patients, 20 each received a SS or coated catheter. Between SS and coated catheters, average indwelling duration was similar and biofilm biomass was 32.068µg/cm2 (95%CI ±21.950) vs. 1.948µg/cm2 (95%CI ±2.595) (P = 0.0111). Confocal microscopy suggested a 93.93% reduction in biofilm biomass on coated catheters. Mineral compositions were different with biofilm and struvite/apatite on SS and calcium oxalate, endogenously derived, on coated catheters. Conclusions Inert BACTIGON® coated catheters appear superior at preventing biofilm formation than SS catheters. Clinical trials are needed to determine the clinical and health economic benefit of this intervention.

Characterization of Thin Polymer Blend Films using ESEM – No Charging, No Staining.

2001 ◽  
Vol 707 ◽  
Author(s):  
Ian C. Bache ◽  
Catherine M. Ramsdale ◽  
D. Steve Thomas ◽  
Ana-Claudia Arias ◽  
J. Devin MacKenzie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Cross Sectional ◽  
Blend Films ◽  
Thin Polymer ◽  
Device Applications ◽  
Scanning Electron

ABSTRACTCharacterising the morphology of thin films for use in device applications requires the ability to study both the structure within the plane of the film, and also through its thickness. Environmental scanning electron microscopy has proved to be a fruitful technique for the study of such films both because contrast can be seen within the film without the need for staining (as is conventionally done for electron microscopy), and because cross-sectional images can be obtained without charging artefacts. The application of ESEM to a particular blend of relevance to photovoltaics is described.

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