scholarly journals Preparation and Characterization of Chemically-Modified Biomaterials and Their Application as Adsorbents of Penicillin G

2018 ◽  
Vol 1 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Jesie Silva ◽  
Lizebel Morante ◽  
Tesfamichael Demeke ◽  
Jacqueline Baah-Twum ◽  
Abel Navarro
Keyword(s):  
Chemical Modification ◽  
Functional Groups ◽  
Negative Impact ◽  
Ph Dependence ◽  
Sem Analysis ◽  
Penicillin G ◽  
Tea Leaves ◽  
Reaction Conditions ◽  
Spent Tea Leaves

The prevalence of antibiotics in water creates microbial resistance and has a negative impact on the ecosystem. Biomaterials such as spent tea leaves are rich in functional groups and are suitable for chemical modification for diverse applications. This research proposes the use of spent tea leaves of chamomile (CM), green tea (GT), and peppermint (PM) as structural scaffolds for the incorporation of carboxyl, sulfonyl, and thiol groups to improve the adsorption of Penicillin G (Pe). Adsorbents characterization reported a higher number of acidic functional groups, mainly in thiolated products. Scanning electron microscopy (SEM) analysis showed changes on the surfaces of the adsorbents due to reaction conditions, with a stronger effect on thiolated and sulfonated adsorbents. Elemental analysis by Energy dispersive X-ray spectrophotometry (EDS) corroborated the chemical modification by the presence of sulfur atoms and the increase in oxygen/carbon ratios. Batch experiments at different pH shows a strong pH-dependence with a high adsorption at pH 8 for all the adsorbents. The adsorption follows the trend CMs > GTs > PMs. Thiolation and sulfonation reported higher adsorptions, which is most likely due to the sulfur bridge formation, reaching adsorption percentages of 25%. These results create a new mindset in the use of spent tea leaves and their chemical modifications for the bioremediation of antibiotics.

Tea Waste: A New Adsorbent for the Removal of Reactive Dyes from Textile Wastewater

2013 ◽  
Vol 803 ◽  
pp. 26-29 ◽  
Author(s):  
Antonio Zuorro ◽  
Maria Laura Santarelli ◽  
Roberto Lavecchia
Keyword(s):  
Low Cost ◽  
Dye Adsorption ◽  
Reactive Dyes ◽  
Textile Wastewater ◽  
Tea Leaves ◽  
Thermally Activated ◽  
Reactive Blue 19 ◽  
Reactive Green 19 ◽  
Spent Tea Leaves

Spent tea leaves (STL), a valueless waste produced during the manufacturing of tea beverages, were investigated as a potential low-cost adsorbent for the removal of the azo dyes Reactive Blue 19 (RB19), Reactive Red 120 (RR 120), Reactive Violet 5 (RV5) and Reactive Green 19 (R19) from wastewater. Untreated STL showed very low removal efficiency (< 7%), while a significant increase in dye adsorption was observed when they were thermally activated. Heating STL to 300 °C for 1 hour resulted in removal efficiencies ranging from 68.5 to 98.4%. Characterization of the waste by FTIR and TG/DTA indicated that major structural and/or chemical changes of the cellulose and hemicellulose components of STL occurred during heating.

scholarly journals Optimizing Spacer Length for Positioning Functional Groups in Bio-Waste

Environments ◽  
2018 ◽  
Vol 5 (9) ◽  
pp. 100 ◽  
Author(s):  
Revathi Iyengar ◽  
Maria Faure-Betancourt ◽  
Saleh Talukdar ◽  
Jinting Ye ◽  
Abel Navarro
Keyword(s):  
Functional Groups ◽  
Amine Group ◽  
Ambient Conditions ◽  
Tea Leaves ◽  
Acid Base ◽  
Spacer Length ◽  
Dipole Interactions ◽  
Green Tea Leaves ◽  
Better Than ◽  
Spent Tea Leaves

The goal of this study was to determine the optimal chain length needed for tethering functional groups on bio-wastes. The purpose of modifying the surface of bio-waste is to improve their affinity for phenols. To this end, four different aminated green tea leaves, with the amine group located at the end of 6, 8, 10, and 12 carbons were synthesized. Green approaches to functionalization lead to fewer reactive sites. Optimizing spacer length is one way to ameliorate this. The aminated tea leaves were prepared by a tosylation reaction followed by displacement with a diamine used in excess. The tea leaves with the amine at the end of six carbons proved to have the best ability to remove 2-chlorophenol (2-CP) from its aqueous solution. It was at least 3–4 times better than native spent tea leaves. The mechanism by which the phenol was removed proved to be primarily an acid–base reaction followed by H-bonding and dipole–dipole interactions. Because of the acid–base interactions, the relatively low-boiling 2-CP did not volatilize off the aminated tea leaves enabling recycling. On the other hand, with activated charcoal, the adsorbed 2-CP volatilized almost completely under ambient conditions.

Synthesis and Characterization of YB66 Nanowires

2008 ◽  
Vol 2 (1) ◽  
Author(s):  
S. Tan ◽  
P. Jash ◽  
M. Trenary
Keyword(s):  
Synthesis Method ◽  
Reaction Times ◽  
Catalyst Particle ◽  
Sem Analysis ◽  
Reaction Conditions ◽  
Tem Analysis ◽  
Analysis Techniques ◽  
Quartz Tube Furnace ◽  
Good Agreement

The objective of the current research is to synthesize yttrium boride (YB66) nanowires. Catalyst assisted growth of the nanowires under the vapor-liquid-solid (VLS) synthesis method was performed in a quartz tube furnace. The pyrolysis of diborane (B2H6) gas over yttrium oxide (Y2O3) powders with a thermally coated layer of nickel catalyst was carried out. The reaction conditions were at 925o C and a pressure of 390 mTorr with varying reaction times. SEM analysis has shown the growth of nanowires with diameters around 400 nm. A catalyst particle was also seen at the tip of the nanowires, confirming growth by the VLS mechanism. Other analysis techniques that were used include Raman spectroscopy and TEM analysis. The Raman spectra of the nanowires were in good agreement with a Raman spectrum obtained on a YB66 single crystal. However, no other evidence was obtained that the nanowires contained yttrium or that the nanowires consisted of YB66.

scholarly journals The Influence of Compatibility on the Structure and Properties of PLA/Lignin Biocomposites by Chemical Modification

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 56 ◽  
Author(s):  
Jianbing Guo ◽  
Xiaolang Chen ◽  
Jian Wang ◽  
Yong He ◽  
Haibo Xie ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Chemical Modification ◽  
Functional Groups ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Poly Lactic Acid ◽  
Rheological Analysis ◽  
Oh Groups ◽  
Interfacial Compatibility

Lignin, a natural amorphous three-dimensional aromatic polymer, is investigated as an appropriate filler for biocomposites. The chemical modification of firsthand lignin is an effective pathway to accomplish acetoacetate functional groups replacing polar hydroxyl (–OH) groups, which capacitates lignin to possess better miscibility with poly(lactic acid) (PLA), compared with acidified lignin (Ac-lignin) and butyric lignin (By-lignin), for the sake of blending with poly(lactic acid) (PLA) to constitute a new biopolymer based composites. Generally speaking, the characterization of all PLA composites has been performed taking advantage of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), dynamic Mechanical analysis (DMA), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), rheological analysis, and tensile test. Visibly, it is significant to highlight that the existence of acetoacetate functional groups enhances the miscibility, interfacial compatibility, and interface interaction between acetoacetate lignin (At-lignin) and PLA. Identical conclusions were obtained in this study where PLA/At-lignin biocomposites furthest maintain the tensile strength of pure PLA.

scholarly journals Physical Training Methods For Mine Rescuers In 2015

2015 ◽  
Vol 66 (1) ◽  
pp. 108-113
Author(s):  
Laurentiu Marin ◽  
Topala Pavel ◽  
Catalina Daniela Marin ◽  
Teodor Sandu
Keyword(s):  
Research And Development ◽  
Chemical Modification ◽  
Training Methods ◽  
Technological Properties ◽  
Reaction Conditions ◽  
Industrial Construction ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Nanocomposite Matrix

Abstract Research and development activities presented were aimed at obtaining a nanocomposite polyurethane matrix with special anti-wear, anti-slip and fire-resistant properties. Research and development works were materialized by obtaining polyurethane nanocomposite matrix, by its physico-chemical modification in order to give the desired technological properties and by characterization of the obtained material. Polyurethane nanocomposite matrix was obtained by reacting a PETOL 3 type polyetherpolyol (having a molecular weight of 5000 UAM) with a diisocyanate under well-established reaction conditions. Target specific technological properties were obtained by physical and chemical modification of polyurethane nanocomposite matrix. The final result was getting a pellicle material based on modified nanocomposite polyurethane, with anti-wear, anti-slip and fire-resistant properties, compatible with most substrates encountered in civil and industrial construction: wood, concrete, metal.

scholarly journals Pengaruh Perlakuan Termal Terhadap Karakteristik Aspal Komposit Berbasis Silika Sekam Padi

2020 ◽  
Vol 8 (1) ◽  
pp. 119-126
Author(s):  
Nita Susanti ◽  
◽  
Juniati Br Simbolon ◽  
Simon Sembiring ◽  
Posman Manurung ◽  
...  
Keyword(s):  
Functional Groups ◽  
Rice Husk ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Effect Of Temperature ◽  
Temperature Variations ◽  
Modified Asphalt ◽  
Asphalt Modification

Synthesis and characterization of asphalt has been modified with silica rice husk with temperature variations of 200, 250, and 300oC. Silica is obtained from rice husk using the sol gel method. Furthermore asphalt and silica are solidified at 110oC. The experiment was conducted to determine the effect of temperature on the microstructure, structure, and functional groups of modified asphalt. SEM analysis shows asphalt modification with a temperature of 300oC in the form of different clumps. XRD analysis showed the phase formed from each temperature was an amorphous phase. The result of the FTIR analysis showed that the functional groups seen in the modified asphalt samples were Si-OH, Si-O-Si, Si-O, and C-H. The compressive strength carried out showed the strength of asphalt again cracks became stronger as the temperature increased.

Plasma-Based Chemical Modification of Epitaxial Graphene

2012 ◽  
Vol 717-720 ◽  
pp. 657-660 ◽  
Author(s):  
Scott G. Walton ◽  
Sandra C. Hernández ◽  
Mira Baraket ◽  
Virginia D. Wheeler ◽  
Luke O. Nyakiti ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electrical Properties ◽  
Chemical Modification ◽  
Functional Groups ◽  
Surface Characterization ◽  
Epitaxial Graphene ◽  
Functionalized Graphene ◽  
Oxygen Functional Groups

In this work, the treatment of epitaxial graphene on SiC using electron beam generated plasmas produced in mixtures of argon and oxygen is demonstrated. The treatment imparts oxygen functional groups on the surface with concentrations ranging up to about 12 at.%, depending on treatment parameters. Surface characterization of the functionalized graphene shows incorporation of oxygen to the lattice by disruption of ∏-bonds, and an altering of bulk electrical properties.

Application of FT Spectroscopy in the Study of Fungi

2008 ◽  
Vol 59 (2) ◽  
pp. 212-215 ◽  
Author(s):  
Catalin Tanase ◽  
Aurel Pui
Keyword(s):  
Functional Groups ◽  
Toxic Substances ◽  
Ft Spectroscopy

The present study is devoted to the IR�FT characterization of some fungi species, to the identification of their main functional groups, as well as to emphasize the presence of some toxic substances in the structure of certain sporiferous plants.

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