Preparation and Characterization of Bacterial Cellulose/TiO2 Hydrogel Nanocomposite

2016 ◽  
Vol 43 ◽  
pp. 73-80 ◽  
Author(s):  
Ricardo Brandes ◽  
Letícia de Souza ◽  
Vanessa Vargas ◽  
Eliana Oliveira ◽  
Alexandre Mikowski ◽  
...  

Bacterial cellulose (BC) is a biopolymer with interesting properties, such as biocompatibility, high tensile strength, high absorption capacity, water retention and high crystallinity. Nanoparticles of titanium dioxide (TiO2) are extremely important in electrical applications, photocatalysis, sensors and biomedical areas. Multifunctional materials, based on bacterial cellulose, with differentiated properties can be designed from the BC/TiO2 nanocomposite by ex situ method of sol-gel immersion. It was manufactured as a nanocomposite consisting of BC/TiO2 hydrogel. Characterizations were carried out by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and fourier transform infrared spectroscopy (FTIR). The morphological analysis of nanocomposite revealed the existence of molecular interaction and adhesion between TiO2 nanoparticles and cellulosic nanofibers matrix, where the presence of Ti peaks in EDS spectra was discovered, proving the successful incorporation of nanoparticles. The FTIR showed modification on the functional groups, suggesting interaction between the components. The manufacturing of a BC/TiO2 nanocomposite by method of sol-gel immersion has a great potential for future applications.

2013 ◽  
Vol 785-786 ◽  
pp. 771-774
Author(s):  
Ai Ping Jin ◽  
Wen Chen ◽  
Quan Yao Zhu

The hybrid guest-host nanocomposite films based on poly (ethylene oxide) (PEO) and molybdenum doped vanadium pentoxide (V0.975Mo0.025)2O5nH2O were prepared by sol-gel and hydrothermal reaction via a two-part process. The electrical properties along and across V-O layers have been evaluated. The results indicate that the proper amount of PEO can increase the electrical conductivity of the films. The electrochromism of the films were investigated by cyclic voltammetry, the ex-situ transmission spectra and photographs. The films display a reversible multichromism (orangegreenbluebrown) upon Li+ion insertion/extraction.


2018 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
A. Zainal Abidin ◽  
G Susanto ◽  
N.M.T. Sastra ◽  
T Puspasari

Synthesis and Characterization of Superabsorbent from Acrylamide Superabsorbent polymer (SAP) is a material that can absorb water in a large amount in a short time. In this research, the polymer has been synthesized from acrylamide monomer (Am) using N,N methylene bisacrylamide (MBA)as a cross-linker and ammonium persulphate (APS) as an initiator. Effects of MBA and APS on the SAP characteristic were studied by varying composition of MBA and APS each of 0.1%-wt, 0.2 %-wt, 0.6 %-wt and 1.0 %-wt. SAP was characterized by measuring its absorption capacity to distilled water. Based on the experiment, the highest absorption capacity for 1 gram SAP is 14.5 gram water. The highest absorption is produced by SAP with APS 0.2 %-wt and MBA 0.6 %-wt. Further studies by using SEM showed that SAP which had high absorption capacity contained a lot of pores with the waving surface. Therefore, the surface contact area between SAP and water is high. Keywords: acrylamide, absorption capacity, superabsorbent polymerAbstrakSuperabsorbent Polymer (SAP) merupakan polimer yang dapat menyerap air dalam jumlah yang sangat banyak. Dalam penelitian ini, polimer tersebut disintesis dari monomer akrilamida menggunakan crosslinker N,N-metilene bisakrilamide (MBA) dan inisiator amonium persulfat (APS). Pengaruh crosslinker dan inisiator terhadap karakteristik SAP dipelajari dengan melakukan variasi komposisi APS dan (MBA) masing-masing sebesar 0,1 %-b, 0,2 %-b, 0,6 %-b, dan 1 %-b. Karakteristik produk SAP dipelajari dengan FTIR untuk menganalisis gugus fungsi yang terbentuk untuk menunjukkan bahwa polimerisasi betul terjadi dan produknya berupa SAP. Pengukuran kemampuan absorpsi SAP terhadap air destilasi menunjukkan bahwa kapasitas absorpsi terbesar yang dihasilkan oleh superabsorbent polymer dari penelitian ini sebesar 14,5 gram air dalam 1 gram produk SAP yang dibuat. Kapasitas terbesar ini dimiliki oleh SAP dengan 0,2 %-b APS dan 0,6 %-b MBA. Studi lebih lanjut dengan SEM menunjukkan bahwa SAP yang memiliki kapasitas absorpsi tertinggi itu mempunyai morfologi permukaan yang berombak dan jumlah pori yang tertinggi sehingga luas permukaan kontak antara SAP dan air juga tertinggi. Kata kunci: akrilamida, kapasitas absorpsi, superabsorbent polymer


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4793
Author(s):  
Adrian Ionut Nicoara ◽  
Alexandra Elena Stoica ◽  
Denisa-Ionela Ene ◽  
Bogdan Stefan Vasile ◽  
Alina Maria Holban ◽  
...  

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.


2007 ◽  
Vol 124-126 ◽  
pp. 363-366 ◽  
Author(s):  
Ai Ping Jin ◽  
Quan Yao Zhu ◽  
Wen Chen ◽  
Victor L. Volkov ◽  
Galina S. Zakharova ◽  
...  

Vanadium pentoxide xerogel films intercalated by poly (ethylene oxide), PEO, were prepared using direct intercalation method via a sol-gel route. The electrical and electrochromic characterization of the films were conducted. The electrical properties along and across V-O layers have been evaluated. The results indicate that the proper amount of PEO can increase the electrical conductivity and charge density of the films. The electrochromism of the films upon lithium intercalation was investigated by ex-situ transmittance measurement. The films display a reversible multichromism (orange green blue) upon Li+ ion insertion/extraction.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2849 ◽  
Author(s):  
Natalia Pogorelova ◽  
Evgeniy Rogachev ◽  
Ilya Digel ◽  
Svetlana Chernigova ◽  
Dmitry Nardin

Bacterial cellulose (BC) is a promising material for biomedical applications due to its unique properties such as high mechanical strength and biocompatibility. This article describes the microbiological synthesis, modification, and characterization of the obtained BC-nanocomposites originating from symbiotic consortium Medusomyces gisevii. Two BC-modifications have been obtained: BC-Ag and BC-calcium phosphate (BC-Ca3(PO4)2). Structure and physicochemical properties of the BC and its modifications were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and infrared Fourier spectroscopy as well as by measurements of mechanical and water holding/absorbing capacities. Topographic analysis of the surface revealed multicomponent thick fibrils (150–160 nm in diameter and about 15 µm in length) constituted by 50–60 nm nanofibrils weaved into a left-hand helix. Distinctive features of Ca-phosphate-modified BC samples were (a) the presence of 500–700 nm entanglements and (b) inclusions of Ca3(PO4)2 crystals. The samples impregnated with Ag nanoparticles exhibited numerous roundish inclusions, about 110 nm in diameter. The boundaries between the organic and inorganic phases were very distinct in both cases. The Ag-modified samples also showed a prominent waving pattern in the packing of nanofibrils. The obtained BC gel films possessed water-holding capacity of about 62.35 g/g. However, the dried (to a constant mass) BC-films later exhibited a low water absorption capacity (3.82 g/g). It was found that decellularized BC samples had 2.4 times larger Young’s modulus and 2.2 times greater tensile strength as compared to dehydrated native BC films. We presume that this was caused by molecular compaction of the BC structure.


Author(s):  
Aline Krindges ◽  
Vanusca Dalosto Jahno ◽  
Fernando Morisso

Incorporation studies of particles in different substrates with herbal assets growing. The objective of this work was the preparation and characterization of micro/nanoparticles containing cymbopogon nardus essential oil; and the incorporation of them on bacterial cellulose. For the development of the membranes was used the static culture medium and for the preparation of micro/nanoparticles was used the nanoprecipitation methodology. The incorporation of micro/nanoparticles was performed on samples of bacterial cellulose in wet and dry form. For the characterization of micro/nanoparticles were carried out analysis of SEM, zeta potential and particle size. For the verification of the incorporation of particulate matter in cellulose, analyses were conducted of SEM and FTIR. The results showed that it is possible the production and incorporation of micro/nanoparticles containing essential oil in bacterial cellulose membranes in wet form with ethanol.


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