In situ Production of Polystyrene Magnetic Nanocomposites through a Batch Suspension Polymerization Process

2011 ◽  
Vol 296 (12) ◽  
pp. 1107-1118 ◽  
Author(s):  
Juliete S. Neves ◽  
Fernando G. de Souza ◽  
Paulo A. Z. Suarez ◽  
Alexandre P. Umpierre ◽  
Fabricio Machado
Keyword(s):  
Suspension Polymerization ◽  
Polymerization Process ◽  
Magnetic Nanocomposites ◽  
In Situ Production

Mass-suspension polymerization process as an efficient tool to produce polymer/clay nanocomposites

2021 ◽  
Vol 04 ◽  
Author(s):  
Mariaugusta F. Mota ◽  
Thainá Araruna ◽  
Nathália M. Campelo ◽  
Meiry Gláucia F. Rodrigues ◽  
Gabriella R. Ferreira ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Suspension Polymerization ◽  
Experimental Studies ◽  
Ethyl Acrylate ◽  
Polymerization Process ◽  
Basal Spacing ◽  
Polymeric Nanocomposites ◽  
Poly Methyl Methacrylate ◽  
Modified Clays

Background: This work presents the preparation and characterization of the polymeric nanocomposites based on methyl methacrylate (MMA), ethyl acrylate (EA), and natural and modified clays. The clays used to prepare the composite were natural green bentonite (GBC-N) and organophilic clays modified with ammonium quaternary salts: Praepagen (GCBP), Dodigen (GCB-D) and Praepagen/Dodigen mixture 1:1 in weight (GCB-P/D). Objective: The experimental studies focused on the evaluation of the effect of clays (in natura and chemically modified) on the final quality of the polymeric nanocomposites containing around 3 wt%. of clay nanocharges in association with MMA to produce poly(methyl methacrylate)/clays; and MMA/EA to form poly(methyl methacrylate-co-ethyl acrylate)/clays. Materials and Methods: The poly(methyl methacrylate)/clay and poly(methyl methacrylate-co-ethyl acrylate)/clay materials were synthesized through mass-suspension polymerization process. The natural and modified green bentonite clays were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) analyzes to understand its effect on the basal spacing, d001 (compared to the pure clay), as a result of cation exchange step, in which also improved the thermal efficiency of the final nanocomposites. Results: The proper incorporation of MMA and MMA/AE monomers between the layers of natural and modified clays occurred through in situ mass-suspension polymerization, leading to a successful exfoliation of clay layers during the growth of the polymer chains. Conclusion: The IR, SEM, TGA and DSC analyzes confirmed the improvement in the thermal property of the composites compared to polymers formed in the absence of clays. The experimental results are very promising, indicating that the experimental protocol based on the in situ formation of polymer nanocomposites by the using sequential mass-suspension polymerization consist of an interesting tool.

An experimental study on the synthesis of poly(vinyl pivalate)-based magnetic nanocomposites through suspension polymerization process

2015 ◽  
Vol 68 ◽  
pp. 441-459 ◽  
Author(s):  
Robson T. Araujo ◽  
Gabriella R. Ferreira ◽  
Tayana Segura ◽  
Fernando G. Souza ◽  
Fabricio Machado
Keyword(s):  
Experimental Study ◽  
Suspension Polymerization ◽  
Polymerization Process ◽  
Magnetic Nanocomposites

Multipath Oxygen-Mediated PET-RAFT Polymerization by Conjugated Organic Polymers Photocatalyst under Red LED Irradiation

2021 ◽  
Author(s):  
Zhen Lu ◽  
Hongjie Yang ◽  
Xiaoling Fu ◽  
Qiuyu Li ◽  
Longqiang Xiao ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Raft Polymerization ◽  
Polymerization Process ◽  
Red Led ◽  
Led Irradiation ◽  
In Situ Production ◽  
Conjugated Organic Polymers

In this contribution, we propose a novel multipath aerobic-mediated reductive quenching pathway (O-RQP) for PET-RAFT polymerization process, where in situ production of superoxide anion radical from molecular oxygen was achieved...

Downflow Bubble Column Electrochemical Reactor (DBCER): In-situ production of H2O2 and O3 to conduct Electroperoxone Process

2021 ◽  
pp. 105148
Author(s):  
Germán Santana-Martínez ◽  
Gabriela Roa-Morales ◽  
Leobardo Gómez-Olivan ◽  
Ever Peralta-Reyes ◽  
Rubí Romero ◽  
...  
Keyword(s):  
Bubble Column ◽  
Electrochemical Reactor ◽  
In Situ Production

scholarly journals Riboflavin Production in Lactococcus lactis: Potential for In Situ Production of Vitamin-Enriched Foods

2004 ◽  
Vol 70 (10) ◽  
pp. 5769-5777 ◽  
Author(s):  
Catherine Burgess ◽  
Mary O'Connell-Motherway ◽  
Wilbert Sybesma ◽  
Jeroen Hugenholtz ◽  
Douwe van Sinderen
Keyword(s):  
Functional Analysis ◽  
Lactic Acid ◽  
Lactococcus Lactis ◽  
Regulatory Region ◽  
Northern Hybridization ◽  
Vitamin B ◽  
Fermented Foods ◽  
Riboflavin Production ◽  
In Situ Production

ABSTRACT This study describes the genetic analysis of the riboflavin (vitamin B2) biosynthetic (rib) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification.

scholarly journals Scaling-up of microbial electrosynthesis with multiple electrodes for in situ production of hydrogen peroxide

iScience ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 102094
Author(s):  
Rusen Zou ◽  
Aliyeh Hasanzadeh ◽  
Alireza Khataee ◽  
Xiaoyong Yang ◽  
Mingyi Xu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Scaling Up ◽  
Microbial Electrosynthesis ◽  
Multiple Electrodes ◽  
Production Of Hydrogen ◽  
In Situ Production

Ship Drag Reduction by Microalgal Biopolymers: A Feasibility Analysis

2007 ◽  
Vol 51 (04) ◽  
pp. 326-337
Author(s):  
K. Gasljevic ◽  
E. F. Matthys
Keyword(s):  
Drag Reduction ◽  
Consumption Rate ◽  
Synthetic Polymers ◽  
Point Of View ◽  
Technical Issues ◽  
Fuel Costs ◽  
Propulsion Power ◽  
Ship Speed ◽  
In Situ Production

We have investigated the feasibility of using high-molecular-weight polysaccharides produced by marine microalgae to reduce the drag on ships and therefore to be able to reduce the needed propulsion power and fuel costs or, alternatively, to increase the ship speed. Experimental and analytical studies were used to answer four critical questions:How suitable are the biopolymers for drag reduction on ships?What is the needed polymer consumption rate at a given level of drag reduction?What is the achievable polymer production rate that can be achieved by the microalgae?What are possible modes of implementation of the proposed technology? It is seen that in situ production of biopolymers by microalgae growing on the hull may be a possible approach to polymeric ship drag reduction. Production of biopolysaccharide off the ship and even harvesting it from the ocean are other possibilities. The use of biopolymers is naturally advantageous from an environmental point of view as well. Some comparison of biopolymers and synthetic polymers is also presented. Several technical issues remain to be investigated, but the information available suggests that biopolymers may be the best additives for drag reduction on ships.

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