Photocatalytic activity and water purification performance of in situ and ex situ synthesized bacterial cellulose‐CuO nanohybrids

2020 ◽  
Author(s):  
Hadi Almasi ◽  
Laleh Mehryar ◽  
Ali Ghadertaj
Keyword(s):  
Photocatalytic Activity ◽  
Bacterial Cellulose ◽  
Water Purification ◽  
Ex Situ

Potential Applications of Bacterial Cellulose in Environmental and Pharmaceutical Sectors

2020 ◽  
Vol 26 (45) ◽  
pp. 5793-5806
Author(s):  
Mazhar Ul-Islam ◽  
Salman Ul-Islam ◽  
Sumayia Yasir ◽  
Atiya Fatima ◽  
Md. Wasi Ahmed ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
3D Structure ◽  
Three Dimensional ◽  
Base Material ◽  
Advanced Materials ◽  
Ex Situ ◽  
Potential Applications ◽  
Wide Readership ◽  
Water Filters

Biopolymers and their composites have been extensively investigated in recent years for multiple applications, especially in environmental, medical, and pharmaceutical fields. Bacterial cellulose (BC) has emerged as a novel biomaterial owing to its nontoxic, high-liquid absorbing and holding capacity, drug-carrying ability, and pollutant absorbing features. Additionally, its web-shaped three-dimensional (3D) structure and hydrogen bonding sites have incited a combination of various nanoparticles, polymers, and other materials with BC in the form of composites. Such BC-based composites have been developed through in-situ, ex-situ, and solution casting methods for targeted applications, such as air and water filters, controlled drug delivery systems, wound dressing materials, and tissue regeneration. This review details the production and development of BCbased composites with different materials and by various methods. It further describes various applications of BC-based composites in the environmental and pharmaceutical sectors, with specific examples from the recent literature. This review could potentially appeal a wide readership in these two emerging fields, where novel and advanced materials for different applications have been developed on a regular basis using BC as the base material.

scholarly journals In Situ and Ex Situ Designed Hydroxyapatite: Bacterial Cellulose Materials with Biomedical Applications

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4793
Author(s):  
Adrian Ionut Nicoara ◽  
Alexandra Elena Stoica ◽  
Denisa-Ionela Ene ◽  
Bogdan Stefan Vasile ◽  
Alina Maria Holban ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Composite Materials ◽  
Bacterial Cellulose ◽  
Antibacterial Properties ◽  
Antimicrobial Effect ◽  
Absorption Capacity ◽  
Coprecipitation Method ◽  
Ex Situ ◽  
Degradation Rates

Hydroxyapatite (HAp) and bacterial cellulose (BC) composite materials represent a promising approach for tissue engineering due to their excellent biocompatibility and bioactivity. This paper presents the synthesis and characterization of two types of materials based on HAp and BC, with antibacterial properties provided by silver nanoparticles (AgNPs). The composite materials were obtained following two routes: (1) HAp was obtained in situ directly in the BC matrix containing different amounts of AgNPs by the coprecipitation method, and (2) HAp was first obtained separately using the coprecipitation method, then combined with BC containing different amounts of AgNPs by ultrasound exposure. The obtained materials were characterized by means of XRD, SEM, and FT-IR, while their antimicrobial effect was evaluated against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and yeast (Candida albicans). The results demonstrated that the obtained composite materials were characterized by a homogenous porous structure and high water absorption capacity (more than 1000% w/w). These materials also possessed low degradation rates (<5% in simulated body fluid (SBF) at 37 °C) and considerable antimicrobial effect due to silver nanoparticles (10–70 nm) embedded in the polymer matrix. These properties could be finetuned by adjusting the content of AgNPs and the synthesis route. The samples prepared using the in situ route had a wider porosity range and better homogeneity.

scholarly journals In situ organic Fenton-like catalysis triggered by anodic polymeric intermediates for electrochemical water purification

2020 ◽  
Vol 117 (49) ◽  
pp. 30966-30972
Author(s):  
Dan-Ni Pei ◽  
Chang Liu ◽  
Ai-Yong Zhang ◽  
Xiao-Qiang Pan ◽  
Han-Qing Yu
Keyword(s):  
Water Purification ◽  
Cost Effective ◽  
Ex Situ ◽  
Pollutant Degradation ◽  
Secondary Pollution ◽  
Redox Active ◽  
Pollution Problem ◽  
Catalytic Stability ◽  
Phenol Conversion

Organic Fenton-like catalysis has been recently developed for water purification, but redox-active compounds have to be ex situ added as oxidant activators, causing secondary pollution problem. Electrochemical oxidation is widely used for pollutant degradation, but suffers from severe electrode fouling caused by high-resistance polymeric intermediates. Herein, we develop an in situ organic Fenton-like catalysis by using the redox-active polymeric intermediates, e.g., benzoquinone, hydroquinone, and quinhydrone, generated in electrochemical pollutant oxidation as H2O2activators. By taking phenol as a target pollutant, we demonstrate that the in situ organic Fenton-like catalysis not only improves pollutant degradation, but also refreshes working electrode with a better catalytic stability. Both1O2nonradical and ·OH radical are generated in the anodic phenol conversion in the in situ organic Fenton-like catalysis. Our findings might provide a new opportunity to develop a simple, efficient, and cost-effective strategy for electrochemical water purification.

Advances in Water Purification for Pond Freshwater Aquaculture

2014 ◽  
Vol 955-959 ◽  
pp. 3928-3932 ◽  
Author(s):  
Hao Ye ◽  
Jian Qiang Zhu ◽  
Gu Li
Keyword(s):  
Water Purification ◽  
Pond Water ◽  
Ex Situ ◽  
Advantages And Disadvantages ◽  
Freshwater Aquaculture ◽  
Aquatic Product ◽  
Freshwater Pond ◽  
Production Practice ◽  
Water Quality Deterioration

Pond freshwater aquaculture, an important production mode, provides aquatic product for people, especially in south of China. Meanwhile, with the development of aquaculture technology of higher density and intensification, the environmental problem and pollution in freshwater pond have become even more acute. In this case, the water purification technology plays an important role in maintenance of the healthy aquaculture and there are a variety of water purification technologies in production practice. This paper is divided into four parts: a) the analysis of the causes of water quality deterioration in freshwater pond, b) the summary of water purification technologies in present, c) the brief analysis of the advantages and disadvantages of the in-situ remediation and ex-situ remediation, d) the prospection of pond water purification technologies in the future.

In situ and ex situ modifications of bacterial cellulose for applications in tissue engineering

2018 ◽  
Vol 82 ◽  
pp. 372-383 ◽  
Author(s):  
Taisa Regina Stumpf ◽  
Xiuying Yang ◽  
Jingchang Zhang ◽  
Xudong Cao
Keyword(s):  
Tissue Engineering ◽  
Bacterial Cellulose ◽  
Ex Situ

Coloration of bacterial cellulose using in situ and ex situ methods

2018 ◽  
Vol 89 (7) ◽  
pp. 1297-1310 ◽  
Author(s):  
Euijin Shim ◽  
Hye Rim Kim
Keyword(s):  
Surface Roughness ◽  
Bacterial Cellulose ◽  
Carbon Sources ◽  
Production Yield ◽  
Ex Situ ◽  
Surface Appearance ◽  
Force Microscopy ◽  
Atomic Force ◽  
In Situ Method

This study aimed to produce colored bacterial cellulose (BC) by adding dye during cultivation (in situ) and by dyeing BC after cultivation (ex situ), respectively. Three different dyestuffs—direct, acid and reactive—were selected for application in the coloring of BC. In the in situ method, the dyestuff is adding into the culture medium. The effects of various dyestuff and carbon sources on the production yield were evaluated. In the ex situ method, the dyestuff, BC gel, was dyed under various dyestuff and dyeing conditions. The production yield of BC cultured by the in situ method in glucose as the carbon source and using a reactive dyestuff was the highest, at about 86%. The ex situ dyeability of BC was improved by setting the dyeing conditions to pH 3 and 135℃. Both methods were evaluated regarding the surface appearance of the BC by scanning electron microscopy (SEM). The SEM showed that the defined cellulose fibril networks retained their inherent nanostructures when the dye penetrated the site through dyeing. The surface roughness of the BC, colored by the two methods, was evaluated by atomic force microscopy. The BC colored by both methods showed smooth surfaces. For BC colored by the in situ method, the surface roughness was 194 nm, indicating that the BC was smoother and finer than that obtained via the ex situ method. In comparing hue and saturation values, the BC colored by the in situ method showed clearer blue colors than that colored by the ex situ method. The in situ method was more effective than the ex situ method for coloring BC.

scholarly journals Bacterial Cellulose as a Versatile Platform for Research and Development of Biomedical Materials

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 624 ◽  
Author(s):  
Selestina Gorgieva
Keyword(s):  
Bacterial Cellulose ◽  
High Purity ◽  
Antimicrobial Properties ◽  
Wound Dressings ◽  
Ex Situ ◽  
Native Form ◽  
Multifunctional Compounds ◽  
Ultra High Purity ◽  
Cell Affinity

The unique pool of features found in intracellular and extracellular bacterial biopolymers attracts a lot of research, with bacterial cellulose (BC) being one of the most versatile and common. BC is an exopolysaccharide consisting solely of cellulose, and the variation in the production process can vary its shape or even its composition when compounding is applied in situ. Together with ex situ modification pathways, including specialised polymers, particles or exclusively functional groups, BC provides a robust platform that yields complex multifunctional compounds that go far beyond ultra-high purity, intrinsic hydrophilicity, mechanical strength and biocompatibility to introduce bioactive, (pH, thermal, electro) responsive, conductive and ‘smart’ properties. This review summarises the research outcomes in BC-medical applications, focusing mainly on data from the past decade (i.e., 2010–2020), with special emphasis on BC nanocomposites as materials and devices applicable in medicine. The high purity and unique structural/mechanical features, in addition to its capacity to closely adhere to irregular skin surfaces, skin tolerance, and demonstrated efficacy in wound healing, all stand as valuable attributes advantageous in topical drug delivery. Numerous studies prove BC compatibility with various human cells, with modifications even improving cell affinity and viability. Even BC represents a physical barrier that can reduce the penetration of bacteria into the tissue, but in its native form does not exhibit antimicrobial properties, therefore carious modifications have been made or specific compounds added to confer antimicrobial or anti-inflammatory properties. Progress in the use of BC-compounds as wound dressings, vascular grafts, and scaffolds for the treatment of cartilage, bone and osteochondral defects, the role as a basement membrane in blood-brain barrier models and many more are discussed to particular extent, emphasising the need for BC compounding to meet specific requirements.

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