scholarly journals Fabrication and Characterization of Lignin/Dendrimer Electrospun Blended Fiber Mats

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 518
Author(s):  
Somaye Akbari ◽  
Addie Bahi ◽  
Ali Farahani ◽  
Abbas S. Milani ◽  
Frank Ko
Keyword(s):  
Thermal Characteristics ◽  
Dendritic Polymers ◽  
Amino Groups ◽  
Fiber Mats ◽  
Potential Applications ◽  
Solution Electrospinning ◽  
Nanofiber Mats ◽  
Softwood Kraft Lignin ◽  
First Time

Blending lignin as the second most abundant polymer in Nature with nanostructured compounds such as dendritic polymers can not only add value to lignin, but also increase its application in various fields. In this study, softwood Kraft lignin/polyamidoamine dendritic polymer (PAMAM) blends were fabricated by the solution electrospinning to produce bead-free nanofiber mats for the first time. The mats were characterized through scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, zeta potential, and thermogravimetry analyses. The chemical intermolecular interactions between the lignin functional groups and abundant amino groups in the PAMAM were verified by FTIR and viscosity measurements. These interactions proved to enhance the mechanical and thermal characteristics of the lignin/PAMAM mats, suggesting their potential applications e.g. in membranes, filtration, controlled release drug delivery, among others.

scholarly journals Fabrication and Characterization of Lignin/Dendrimer Electrospun Blended Fiber Mats

2020 ◽  
Author(s):  
Somaye Akbari ◽  
Addie Bahi ◽  
Ali Farahani ◽  
Abbas Milani ◽  
Frank Ko
Keyword(s):  
Thermal Characteristics ◽  
Dendritic Polymers ◽  
Amino Groups ◽  
Fiber Mats ◽  
Electrospinning Method ◽  
Potential Applications ◽  
Solution Electrospinning ◽  
Nanofiber Mats ◽  
Softwood Kraft Lignin

Blending lignin as the second most abundant polymer in nature with nanostructured compounds such as dendritic polymers will not only add value to lignin, but also increase its application in various fields. In this study, softwood Kraft lignin/polyamidoamine dendritic polymer (PAMAM) blends were fabricated by solution electrospinning method to produce bead-free nanofiber mats. The mats were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), zeta potential, and thermogravimetry analysis (TGA). The chemical intermolecular interactions between lignin functional groups and abundant amino groups in PAMAM were investigated by FTIR and viscosity measurement. These interactions enhanced the mechanical and thermal characteristics of lignin/PAMAM mats, providing further potential applications at industry level.

Preparation and Characterization of Chitosan-Casein Phosphopeptides Biocomposite Coatings on the Medical Titanium Alloy

2011 ◽  
Vol 480-481 ◽  
pp. 1065-1069
Author(s):  
Bin Liu ◽  
Lin Wang ◽  
Yin Zhong Bu ◽  
Sheng Rong Yang ◽  
Jin Qing Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflectance ◽  
Ti Alloy ◽  
Force Microscopy ◽  
Implant Materials ◽  
Atomic Force ◽  
Casein Phosphopeptides ◽  
Potential Applications ◽  
First Time

Titanium (Ti) and its alloys have been applied in orthopedics as one of the most popular biomedical metallic implant materials. In this work, to enhance the bioactivity, the surface of Ti alloy pre-modified by silane coupling agent and glutaraldehyde was covalently grafted with chitosan (CS) via biochemical multistep self-assembled method. Then, for the first time, the achieved surface was further immobilized with casein phosphopeptides (CPP), which are one group of bioactive peptides released from caseins in the digestive tract and can facilitate the calcium adsorption and usage, to form CS-CPP biocomposite coatings. The structure and composition of the fabricated coatings were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). As the experimental results indicated, multi-step assembly was successfully performed, and the CS and CPP were assembled onto the Ti alloy surface orderly. It is anticipated that the Ti alloys modified by CS-CPP biocomposite coatings will find potential applications as implant materials in biomedical fields.

Evaluation and Characterization of Titanium to Glass Anodic Bonding

2008 ◽  
Author(s):  
Qiong Shu ◽  
Juan Su ◽  
Gang Zhao ◽  
Ying Wang ◽  
Jing Chen
Keyword(s):  
Bonding Temperature ◽  
Soda Lime ◽  
Anodic Bonding ◽  
Soda Lime Glass ◽  
Glass Wafer ◽  
Wafer Level ◽  
Different Types ◽  
Potential Applications ◽  
First Time

In this paper, Ti-Glass anodic bonding is investigated on both chip and wafer level. In concern of coefficients of thermal expansion (CTE) match, three different types of ion-containing glasses are evaluated: Pyrex 7740, D-263T and soda lime glass. By applying a potential between the two chips and heating them beyond 350°C, soda lime glass samples are successfully bonded with titanium. The influence of the bonding temperature on the bonding strength is revealed. For the first time, wafer level Ti-Glass bond is carried out, a 157-μm-thick titanium wafer is successfully bonded to a 1000-μm-thick soda glass wafer at 450°C and applying a voltage of 800V and a force of 1000N for 30min, over 60% of the surface are joined. The results are helpful to define potential applications in certain field of microsystems.

scholarly journals Permeability of Electrospun Superhydrophobic Nanofiber Mats

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Sarfaraz U. Patel ◽  
Gabriel M. Manzo ◽  
Shagufta U. Patel ◽  
Prashant S. Kulkarni ◽  
George G. Chase
Keyword(s):  
Fiber Diameter ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Diameter Distribution ◽  
Fibrous Media ◽  
Water Contact ◽  
Fiber Mats ◽  
Nonwoven Fiber ◽  
Nanofiber Mats

This paper discusses the fabrication and characterization of electrospun nanofiber mats made up of poly(4-methyl-1-pentene) polymer. The polymer was electrospun in different weight concentrations. The mats were characterized by their basis weight, fiber diameter distribution, contact angles, contact angle hysteresis, and air permeability. All of the electrospun nonwoven fiber mats had water contact angles greater than 150 degrees making them superhydrophobic. The permeabilities of the mats were empirically fitted to the mat basis weight by a linear relation. The experimentally measured air permeabilities were significantly larger than the permeabilities predicted by the Kuwabara model for fibrous media.

scholarly journals Microstructure and Fluctuation-Induced Conductivity Analysis of Bi2Sr2CaCu2O8+δ (Bi-2212) Nanowire Fabrics

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 986
Author(s):  
Michael Rudolf Koblischka ◽  
Anjela Koblischka-Veneva ◽  
XianLin Zeng ◽  
Essia Hannachi ◽  
Yassine Slimani
Keyword(s):  
Three Dimensional ◽  
Short Wave ◽  
Superconducting Transition ◽  
Fiber Mats ◽  
Nanowire Network ◽  
Fluctuation Induced Conductivity ◽  
The Individual ◽  
Nanofiber Mats ◽  
Nanowire Networks ◽  
First Time

Resistance measurements were performed on Bi2Sr2CaCu2O8+δ (Bi-2212) fabric-like nanowire networks or nanofiber mats in the temperature interval 3 K ≤T≤ 300 K. The nanowire fabrics were prepared by means of electrospinning, and consist of long (up to 100 μm) individual nanowires with a mean diameter of 250 nm. The microstructure of the nanowire network fiber mats and of the individual nanowires was thoroughly characterized by electron microscopy showing that the nanowires can be as thin as a single Bi-2212 grain. The polycrystalline nanowires are found to have a texture in the direction of the original polymer nanowire. The overall structure of the nanofiber mats is characterized by numerous interconnects among the nanowires, which enable current flow across the whole sample. The fluctuation-induced conductivity (excess conductivity) above the superconducting transition temperature, Tc, was analyzed using the Aslamzov-Larkin model. Four distinct fluctuation regimes (short-wave, two-dimensional, three-dimensional and critical fluctuation regimes) could be identified in the Bi-2212 nanowire fabric samples. These regimes in such nanowire network samples are discussed in detail for the first time. Based on this analysis, we determine several superconducting parameters from the resistance data.

Preparation and Characterization of Spidroin and PLLA Blended Nanofiber Mats

2011 ◽  
Vol 175-176 ◽  
pp. 127-131 ◽  
Author(s):  
Min Zhang ◽  
Ye Mei Zhang ◽  
Wei Wu ◽  
Ai Li Zhang ◽  
Zhi Juan Pan
Keyword(s):  
Spider Silk ◽  
Molecular Conformation ◽  
Random Coil ◽  
Composite Fibers ◽  
Fiber Mats ◽  
Initial Modulus ◽  
Plla Fiber ◽  
Α Helix ◽  
Nanofiber Mats

Due to the exceptional biocompatibility of spider silk and poly-L-lactic acid (PLLA), electrospun PLLA or spidroin fiber mat is one of the best biomaterials. The diameter of electropun PLLA fiber decreased and mechanical property of such fiber mats was improved once some spidroin was added into PLLA/Hexaflorisopropanol (HFIP) solution. The influence of electrospinning voltage and distance on the shape and mechanical properties of spidroin/PLLA composite fibers was investigated as well as the molecular conformation and crystalline structure of the electrospun fibers. The results revealed that the diameter of spidroin/PLLA fiber was non-uniform, which varied from 300nm to 1000nm. The content of random coil or α-helix structure was about 45%, and spidroin presented a crystal structure separated with PLLA in their composite fibers. With the raise of voltage, the proportion of nano-sized fibers in an electrospun spidroin/PLLA fiber mat increased and tended to be unchanged. The breaking strength of the mat was improved following the increase of voltage. Meanwhile, the ratio of nano-sized fibers and initial modulus of the spidroin/PLLA fiber mat underwent the convex change against the electrospinning distance between the needle and collector.

scholarly journals High Yielding, One-Pot Synthesis of Bis(1H-indazol-1-yl)methane Catalyzed by 3d-Metal Salts

Reactions ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 59-69
Author(s):  
Natalie M. Lind ◽  
Natalie S. Joe ◽  
Brian S. Newell ◽  
Aimee M. Morris
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Structural Similarity ◽  
Complete Characterization ◽  
X Ray Diffraction ◽  
One Pot ◽  
One Pot Synthesis ◽  
Potential Applications ◽  
Metal Catalyzed ◽  
First Time

Synthetic access to poly(indazolyl)methanes has limited their study despite their structural similarity to the highly investigated chelating poly(pyrazolyl)methanes and their potentially important indazole moiety. Herein is presented a high yielding, one-pot synthesis for the 3d-metal catalyzed formation of bis(1H-indazol-1-yl)methane from 1H-indazole utilizing dimethylsulfoxide as the methylene source. Complete characterization of bis(1H-indazol-1-yl)methane is given with 1H and 13C NMR, UV/Vis, FTIR, high resolution mass spectrometry and for the first time, single crystal X-ray diffraction. This simple, inexpensive pathway to yield exclusively bis(1H-indazol-1-yl)methane provides synthetic access to further investigate the coordination and potential applications of the family of bis(indazolyl)methanes.

scholarly journals Purification and characterization of embryo-specific soy urease (Glycine max) and its antifungal potential against Paracoccidioides brasiliensis

2021 ◽  
Vol 46 (1SI) ◽  
pp. 41-52
Author(s):  
Elisângela Andrade Ângelo ◽  
Tainá Michelle Da Cruz ◽  
José Renato Pattaro Júnior ◽  
Daniele Maria Zanzarin ◽  
Franciele Abigail Vilugron Rodrigues ◽  
...  
Keyword(s):  
Glycine Max ◽  
Biochemical Characterization ◽  
Paracoccidioides Brasiliensis ◽  
Maximum Velocity ◽  
Enzymatic Function ◽  
Potential Applications ◽  
First Time

Ureases are amidohydrolases that catalyze the hydrolysis of urea to ammonia and carbamate. In addition to the enzymatic function, ureases have fungitoxic and insecticidal function, which are independent of their catalytic activity. Soy (Glycine max) has two main urease isoforms: ubiquitous and embryo-specific, the latter is present in beans. In view of the potential applications of ureases, this work aimed to extract, purify, characterize the structure, activity and fungitoxic activity of soy urease against Paracoccidioides brasiliensis. The biochemical characterization was performed, in terms of optimal pH and temperature, as well as the determination of the Michaelis�Menten constant (KM) and maximum velocity (Vmax). The protein sequence was identified by mass spectrometry and used in computational modeling of the biological structure. The optimum pH and temperature of the enzyme were 6.5 and 65 �C, respectively, KM 526 mmol L-1 and Vmax 7.4 mmol L-1NH3׵gurease-1�s-1 and biological unity as a trimer. The antifungal activity assays (in vitro) were promising, showing a fungicidal profile of the urease, with a minimum inhibitory concentration of 10 �g�mL-1. This work demonstrated, for the first time, the fungitoxic activity of embryo-specific soy urease against the Pb18 strain of P. brasiliensis.

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

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