scholarly journals Recent Advances in the Synthesis of Nanocellulose Functionalized–Hybrid Membranes and Application in Water Quality Improvement

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 611
Author(s):  
Sandrine Mbakop ◽  
Lebea N. Nthunya ◽  
Maurice S. Onyango
Keyword(s):  
Membrane Filtration ◽  
Low Cost ◽  
Composite Membranes ◽  
Research Field ◽  
Effective Control ◽  
High Tech ◽  
Separation And Purification ◽  
Natural Polymers ◽  
Nanocomposite Membranes ◽  
Processing Technologies

The increasing discharge of voluminous non or partially treated wastewaters characterized by complex contaminants poses significant ecological and health risks. Particularly, this practice impacts negatively on socio-economic, technological, industrial, and agricultural development. Therefore, effective control of water pollution is imperative. Over the past decade, membrane filtration has been established as an effective and commercially attractive technology for the separation and purification of water. The performance of membrane-based technologies relies on the intrinsic properties of the membrane barrier itself. As a result, the development of innovative techniques for the preparation of highly efficient membranes has received remarkable attention. Moreover, growing concerns related to cost-effective and greener technologies have induced the need for eco-friendly, renewable, biodegradable, and sustainable source materials for membrane fabrication. Recently, advances in nanotechnology have led to the development of new high-tech nanomaterials from natural polymers (e.g., cellulose) for the preparation of environmentally benign nanocomposite membranes. The synthesis of nanocomposite membranes using nanocelluloses (NCs) has become a prominent research field. This is attributed to the exceptional characteristics of these nanomaterials (NMs) namely; excellent and tuneable surface chemistry, high mechanical strength, low-cost, biodegradability, biocompatibility, and renewability. For this purpose, the current paper opens with a comprehensive yet concise description of the various types of NCs and their most broadly utilized production techniques. This is closely followed by a critical review of how NC substrates and their surface-modified versions affect the performance of the fabricated NC-based membranes in various filtration processes. Finally, the most recent processing technologies for the preparation of functionalized NCs-based composite membranes are discussed in detail and their hybrid characteristics relevant to membrane filtration processes are highlighted.

scholarly journals Synthesis and Characterization of Novel Green Hybrid Nanocomposites for Application as Proton Exchange Membranes in Direct Borohydride Fuel Cells

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1180 ◽  
Author(s):  
Marwa H. Gouda ◽  
Noha A. Elessawy ◽  
Diogo M.F. Santos
Keyword(s):  
Electron Microscopy ◽  
Fuel Cells ◽  
Low Cost ◽  
Composite Membranes ◽  
Proton Exchange ◽  
Hybrid Nanocomposites ◽  
Poly Vinyl Alcohol ◽  
Nanocomposite Membranes ◽  
X Ray ◽  
Direct Borohydride Fuel Cells

Organic–inorganic nanocomposite membranes for potential application in direct borohydride fuel cells (DBFCs) are formulated from sulfonated poly(vinyl alcohol) (SPVA) with the incorporation of (PO4-TiO2) and (SO4-TiO2) nanotubes as doping agents. The functionalization of PVA to SPVA was done by using a 4-sulfophthalic acid as an ionic crosslinker and sulfonating agent. Morphological and structural characterization by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) confirmed the successful synthesis of the doping agents and their incorporation into the polymer. The influence of PO4-TiO2 and SO4-TiO2 doping and their content on the physicochemical properties of the nanocomposite membranes was evaluated. Swelling degree and water uptake gradually reduced to 7% and 13%, respectively, with increasing doping agent concentration. Ion exchange capacity and ionic conductivity of the membrane with 3 wt.% doping agents were raised 5 and 7 times, respectively, compared to the undoped one. The thermal and oxidative stability and tensile strength also increased with the doping content. Furthermore, lower borohydride permeability (0.32 × 10−6 cm2 s−1) was measured for the membranes with higher amount of inorganic doping agents when compared to the undoped membrane (0.71 × 10−5 cm2 s−1) and Nafion®117 (0.40 × 10−6 cm2 s−1). These results pave the way for a green, simple and low-cost approach for the development of composite membranes for practical DBFCs.

Carbon nanotube composite membranes for small ‘designer’ water treatment systems

2014 ◽  
Vol 14 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Haiou Huang ◽  
Howard Fairbrother ◽  
Benoit Teychene ◽  
Gaurav Ajmani ◽  
Talia Abbott Chalew ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Filtration ◽  
Low Cost ◽  
Composite Membranes ◽  
Water Systems ◽  
Treatment Technology ◽  
Ongoing Research ◽  
Small Communities ◽  
Small Water ◽  
Filtration Cycle

Small water systems that serve fewer than a few thousand persons are often less safe and less sustainable than large drinking water systems due to lack of suitable technologies. This ongoing research aims to develop a novel water treatment technology for small communities. By layering structured, functional carbon nanotubes (CNT) onto low pressure membranes (LPMs), composite membranes were prepared to remove different organic and inorganic contaminants from water, including heavy metals, viruses, natural organic matter, and organic micropollutants. The removal efficiencies varied from over 99.9% (for cadmium) to above 60% (for humic substances). A low-cost CNT formed an antifouling layer that removed membrane foulants by depth filtration, thereby extending the membrane filtration cycle over five-fold. When the CNTs were layered inside hollow fiber membranes, superb backwashable properties were observed, allowing the operation of CNT-modified membranes under full-scale treatment conditions. Moreover, a systematic study of CNT rejection by LPMs found that commercially available LPMs efficiently prevented CNT breakthrough, thus ensuring nanosafety of the treated water. By varying the composition and structure of functional CNT layers, energy-efficient composite membranes may be economically produced for designer water treatment systems and applied in small communities.

scholarly journals Efficient Chitosan/Nitrogen-Doped Reduced Graphene Oxide Composite Membranes for Direct Alkaline Ethanol Fuel Cells

2021 ◽  
Vol 22 (4) ◽  
pp. 1740 ◽  
Author(s):  
Selestina Gorgieva ◽  
Azra Osmić ◽  
Silvo Hribernik ◽  
Mojca Božič ◽  
Jurij Svete ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Composite Membranes ◽  
Nanocomposite Membranes ◽  
Ethanol Fuel ◽  
Direct Ethanol Fuel Cells ◽  
Graphene Oxides ◽  
Reduced Graphene ◽  
Structure Morphology ◽  
Graphene Derivatives ◽  
Doped Graphene

Herein, we prepared a series of nanocomposite membranes based on chitosan (CS) and three compositionally and structurally different N-doped graphene derivatives. Two-dimensional (2D) and quasi 1D N-doped reduced graphene oxides (N-rGO) and nanoribbons (N-rGONRs), as well as 3D porous N-doped graphitic polyenaminone particles (N-pEAO), were synthesized and characterized fully to confirm their graphitic structure, morphology, and nitrogen (pyridinic, pyrrolic, and quaternary or graphitic) group contents. The largest (0.07%) loading of N-doped graphene derivatives impacted the morphology of the CS membrane significantly, reducing the crystallinity, tensile properties, and the KOH uptake, and increasing (by almost 10-fold) the ethanol permeability. Within direct alkaline ethanol test cells, it was found that CS/N rGONRs (0.07 %) membrane (Pmax. = 3.7 mWcm−2) outperformed the pristine CS membrane significantly (Pmax. = 2.2 mWcm−2), suggesting the potential of the newly proposed membranes for application in direct ethanol fuel cells.

scholarly journals Preparation and Antimicrobial Activity of Chitosan and Its Derivatives: A Concise Review

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3694
Author(s):  
Luminita Georgeta Confederat ◽  
Cristina Gabriela Tuchilus ◽  
Maria Dragan ◽  
Mousa Sha’at ◽  
Oana Maria Dragostin
Keyword(s):  
Antimicrobial Activity ◽  
Low Cost ◽  
Hydroxyl Groups ◽  
Pharmacological Properties ◽  
Natural Polymers ◽  
Economic Sectors ◽  
Physico Chemical ◽  
Long Time ◽  
Resistant Strains ◽  
Strength And Durability

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

Clay Intercalated PVA-Nafion Bipolymer Matrix as Proton Conducting Nanocomposite Membrane for PEM Fuel Cells

2014 ◽  
Vol 807 ◽  
pp. 161-168
Author(s):  
B. Narayanamoorthy ◽  
B. Dineshkumar ◽  
S. Balaji
Keyword(s):  
Sol Gel ◽  
Composite Membranes ◽  
Pem Fuel Cells ◽  
The Other ◽  
Hybrid Nanocomposite ◽  
Nanocomposite Membranes ◽  
Free Standing ◽  
Ft Ir ◽  
Clay Materials ◽  
Sem Analyses

The amino functionalized magnesium phyllosilicate clay (AC) intercalated over PVA-Nafion hybrid nanocomposite membranes were prepared by sol-gel method. The free standing membranes were obtained by solution recasting. The composition of clay materials such as AC and montmorillonite (MMT) was varied between 2-10 wt.% with respect to PVA-Nafion content. The molecular interactions and surface morphology of nanocomposite membranes were investigated by FT-IR and SEM analyses respectively. The thermal and mechanical stabilities of nanocomposite membranes were studied using TGA and Nanoindentation techniques. For 6 wt. % AC/PVA-Nafion, TGA results showed no appreciable mass change up to 380 °C and hardness calculated from nanoindentation studies was nearly 30 % higher than the other compositions. An improved conductivity was obtained for 6 wt. % AC/PVA-Nafion (1.4×10-2 S/cm) compared to pure Nafion (1.2×10-2 S/cm) and PVA-Nafion and MMT/PVA-Nafion composite membranes. From these studies, we observed that 6 wt. % AC/PVA-Nafion membrane possessed a good conductivity with higher thermal and mechanical stabilities.

scholarly journals Modelling of new generation plasma optical devices

Nukleonika ◽  
2016 ◽  
Vol 61 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Irina V. Litovko ◽  
Alexy A. Goncharov ◽  
Andrew N. Dobrovolskiy ◽  
Lily V. Naiko ◽  
Irina V. Naiko
Keyword(s):  
Low Cost ◽  
Rocket Engine ◽  
Cost Effective ◽  
Optical Devices ◽  
High Tech ◽  
Practical Applications ◽  
Plasma Accelerators ◽  
New Generation ◽  
Closed Electron ◽  
Positive Space

Abstract The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.

scholarly journals A High-Frequency Sound based PGC Demodulation Scheme for Fiber Optics Hydrophone

2021 ◽  
Author(s):  
Yunjie Shi ◽  
Mengke Yin ◽  
Zijue Zhu ◽  
Shun Wang ◽  
Panting Niu ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Sound Source ◽  
Acoustic Signal ◽  
High Frequency ◽  
Fiber Optic ◽  
Low Cost ◽  
Research Field ◽  
Interference Signal ◽  
High Frequency Sound ◽  
Frequency Sound

Abstract In the research field of fiber-optic hydrophone, the performance of demodulation scheme is crucial. In this work, a phase-generated-carrier (PGC) demodulation scheme based on high-frequency sound source is proposed. Highfrequency acoustic signal from the external sound source is applied to the fiber-optic hydrophone to achieve phase modulation of the interference signal instead of the piezo-electrical transducer (PZT) or frequency-modulated laser. It possesses the merits of low system complexity and low cost. Through the acoustic detection experiment, we achieve demodulation of acoustic signal at frequency varying from 300 Hz to 800 Hz, and the signal-to-noise ratio (SNR) is higher than 45 dB. Furthermore, the proposed scheme is successfully applied to time division multiplexing (TDM) experiment.

scholarly journals A Multidisciplinary Perspective of Ultra-Processed Foods and Associated Food Processing Technologies: A View of the Sustainable Road Ahead

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3948
Author(s):  
Francesco Capozzi ◽  
Faidon Magkos ◽  
Fabio Fava ◽  
Gregorio Paolo Milani ◽  
Carlo Agostoni ◽  
...  
Keyword(s):  
Health Outcomes ◽  
Food Processing ◽  
Low Cost ◽  
Classification Systems ◽  
Processed Foods ◽  
Processing Technologies ◽  
Adverse Health Outcomes ◽  
Increased Risk ◽  
Multidisciplinary Perspective ◽  
By Products

Ultra-processed foods (UPFs) are negatively perceived by part of the scientific community, the public, and policymakers alike, to the extent they are sometimes referred to as not “real food”. Many observational surveys have linked consumption of UPFs to adverse health outcomes. This narrative synthesis and scientific reappraisal of available evidence aims to: (i) critically evaluate UPF-related scientific literature on diet and disease and identify possible research gaps or biases in the interpretation of data; (ii) emphasize the innovative potential of various processing technologies that can lead to modifications of the food matrix with beneficial health effects; (iii) highlight the possible links between processing, sustainability and circular economy through the valorisation of by-products; and (iv) delineate the conceptual parameters of new paradigms in food evaluation and classification systems. Although greater consumption of UPFs has been associated with obesity, unfavorable cardiometabolic risk factor profiles, and increased risk for non-communicable diseases, whether specific food processing techniques leading to ultra-processed formulations are responsible for the observed links between UPFs and various health outcomes remains elusive and far from being understood. Evolving technologies can be used in the context of sustainable valorisation of food processing by-products to create novel, low-cost UPFs with improved nutritional value and health potential. New paradigms of food evaluation and assessment should be funded and developed on several novel pillars—enginomics, signalling, and precision nutrition—taking advantage of available digital technologies and artificial intelligence. Research is needed to generate required scientific knowledge to either expand the current or create new food evaluation and classification systems, incorporating processing aspects that may have a significant impact on health and wellness, together with factors related to the personalization of foods and diets, while not neglecting recycling and sustainability aspects. The complexity and the predicted immense size of these tasks calls for open innovation mentality and a new mindset promoting multidisciplinary collaborations and partnerships between academia and industry.

scholarly journals Dispute Settlement Practices through the Religious Court’s Mobile Court (Sidang Keliling)

FIAT JUSTISIA ◽  
2020 ◽  
Vol 14 (3) ◽  
pp. 287
Author(s):  
Hazar Kusmayanti ◽  
Sherly Ayuna Puteri
Keyword(s):  
Control System ◽  
Dispute Settlement ◽  
Low Cost ◽  
Effective Control ◽  
Circuit Court ◽  
Procedural Law ◽  
To Come ◽  
Circuit Courts ◽  
Religious Courts

This research is attempted to analyze the practices of mobile court and compare it with others. Based on the results of the study, the conclusions that can be obtained are that the implementation of the circuit court conducted at the Tasikmalaya District Religious Court has fulfilled several principles of civil procedural law, namely fast, simple and low cost. Among them when people who experience obstacles to come to the court office for reasons of distance, transportation and costs of the court come directly to the location, the bureaucracy is not complicated meaning that the implementation of the trial must be completed no later than 4 times the hearing, and the existence of an effective control system and various elements. Obstacles in the conduct of circuit courts include no standard guidelines for the holding of circuit courts, not all cases registered by residents are resolved in circuit courts, limited budgets, cases that have not been heard are all without prodeo, facilities and infrastructure, and not all religious courts hold circuit courts.

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