Preparation and Characterization on Cellulose Nanofiber Film

2010 ◽  
Vol 654-656 ◽  
pp. 1760-1763 ◽  
Author(s):  
Li Yuan Zhang ◽  
Takuya Tsuzuki ◽  
Xun Gai Wang
Keyword(s):  
Cellulose Nanofibers ◽  
Average Diameter ◽  
Cellulose Nanofiber ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Image ◽  
Potential Applications ◽  
Reflectance Analysis ◽  
Nanofiber Film

In this study, cellulose nanofibers were obtained from wood pulp using a chemo-mechanical method and thin films were made of these cellulose nanofibers. The morphology of the films was studied by scanning electron microscopy (SEM). SEM image analysis revealed that the films were composed of cellulose nanofibers with an average diameter of around 32 nm. Other properties were also characterized, including the degree of crystallinity by X-ray diffraction, chemical bonding by infrared attenuated total reflectance analysis, and thermal properties by differential scanning calorimetry. The foldable, strong, and optically translucent cellulose nanofiber films thus obtained have many potential applications as micro/nano electronic devices, biosensors and filtration media, etc.

scholarly journals Tuning the mechanical properties and degradation properties of polydioxanone isothermal annealing

2020 ◽  
Vol 44 (5) ◽  
pp. 1430-1444
Author(s):  
Xiliang LIU ◽  
Shaomin FENG ◽  
Xin WANG ◽  
Jin QI ◽  
Dong LEI ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Isothermal Annealing ◽  
Hydrolytic Degradation ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Optical Micrograph ◽  
Potential Applications ◽  
Degradation Properties ◽  
The Degree Of Crystallinity

Polydioxanone (PPDO) is synthesized by ring-opening polymerization of p-dioxanone, using stannous octoate as the catalyst. The polarized optical micrograph (POM) shows thes pherulite growth rate of PPDO decreases with an increase in the isothermal crystallization temperature. PPDO is compression-molded into bars, and PPDO bars are subjected to isothermal annealing at a range of temperatures (Ta = 50, 60, 70, 80, 90, and 100 °C), and correspond to three different annealing times (ta = 1h, 2h, 3h). The effect on PPDO is investigated by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). With an increase in Ta and ta, the grain size and the degree of crystallinity also increase. Meanwhile, the tensile strength is significantly improved. The PPDO bars (90 °C, 2 h) reach the maximum crystallinity (57.21%) and the maximum tensile strength (41.1 MPa). Interestingly, the heat treatment process does not result in serious thermal degradation. It is observed that the hydrolytic degradation of the annealed PPDO is delayed to some extent. Thus, annealed PPDO might have potential applications, particularly in the fields of orthopedic fixation and tissue engineering.

scholarly journals Biobased Engineering Thermoplastics: Poly(butylene 2,5-furandicarboxylate) Blends

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 937 ◽  
Author(s):  
Niki Poulopoulou ◽  
George Kantoutsis ◽  
Dimitrios N. Bikiaris ◽  
Dimitris S. Achilias ◽  
Maria Kapnisti ◽  
...  
Keyword(s):  
Renewable Resources ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Reactive Blending ◽  
Scanning Calorimetry ◽  
Melt Polycondensation ◽  
Poly Ethylene Terephthalate ◽  
Furandicarboxylic Acid ◽  
Poly Ethylene ◽  
Poly Propylene

Poly(butylene 2,5-furandicarboxylate) (PBF) constitutes a new engineering polyester produced from renewable resources, as it is synthesized from 2,5-furandicarboxylic acid (2,5-FDCA) and 1,4-butanediol (1,4-BD), both formed from sugars coming from biomass. In this research, initially high-molecular-weight PBF was synthesized by applying the melt polycondensation method and using the dimethylester of FDCA as the monomer. Furthermore, five different series of PBF blends were prepared, namely poly(l-lactic acid)–poly(butylene 2,5-furandicarboxylate) (PLA–PBF), poly(ethylene terephthalate)–poly(butylene 2,5-furandicarboxylate) (PET–PBF), poly(propylene terephthalate)–poly(butylene 2,5-furandicarboxylate) (PPT–PBF), poly(butylene 2,6-naphthalenedicarboxylate)-poly(butylene 2,5-furandicarboxylate) (PBN–PBF), and polycarbonate–poly(butylene 2,5-furandicarboxylate) (PC–PBF), by dissolving the polyesters in a trifluoroacetic acid/chloroform mixture (1/4 v/v) followed by coprecipitation as a result of adding the solutions into excess of cold methanol. The wide-angle X-ray diffraction (WAXD) patterns of the as-prepared blends showed that mixtures of crystals of the blend components were formed, except for PC which did not crystallize. In general, a lower degree of crystallinity was observed at intermediate compositions. The differential scanning calorimetry (DSC) heating scans for the melt-quenched samples proved homogeneity in the case of PET–PBF blends. In the remaining cases, the blend components showed distinct Tgs. In PPT–PBF blends, there was a shift of the Tgs to intermediate values, showing some partial miscibility. Reactive blending proved to improve compatibility of the PBN–PBF blends.

scholarly journals Hemp Fibre Reinforced Poly(Lactic Acid) Composites

2007 ◽  
Vol 29-30 ◽  
pp. 337-340 ◽  
Author(s):  
M.A. Sawpan ◽  
K.L. Pickering ◽  
Alan Fernyhough
Keyword(s):  
Lactic Acid ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Hemp Fibre ◽  
Reinforcing Material ◽  
Fibre Loading ◽  
The Degree Of Crystallinity

The potential of hemp fibre as a reinforcing material for Poly(lactic acid) (PLA) was investigated. Good interaction between hemp fibre and PLA resulted in increases of 100% for Young’s modulus and 30% for tensile strength of composites containing 30 wt% fibre. Different predictive ‘rule of mixtures’ models (e.g. Parallel, Series and Hirsch) were assessed regarding the dependence of tensile properties on fibre loading. Limited agreement with models was observed. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) studies showed that hemp fibre increased the degree of crystallinity in PLA composites.

Study of the structure and thermal characteristics of nanocomposites based on polyvinyl alcohol and intercalated montmorillonite

2019 ◽  
pp. 089270571987919
Author(s):  
Volodymyr Krasinskyi ◽  
Ivan Gajdos ◽  
Oleh Suberlyak ◽  
Viktoria Antoniuk ◽  
Tomasz Jachowicz
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Acrylic Acid ◽  
Polyvinyl Alcohol ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Degree Of Crystallinity

The structure and thermal characteristics of nanocomposites based on polyvinyl alcohol (PVA) and montmorillonite (MMT) intercalated with polyvinylpyrrolidone were investigated by X-ray diffraction analysis and differential scanning calorimetry. The modification of PVA with intercalated MMT reduces the degree of crystallinity of the resulting nanocomposites but significantly increases their thermal stability. Under ultrasound, the intercalated MMT was completely distributed in a PVA solution and formed a monocrystalline structure. Films based on PVA with modified MMT were cross-linked at 110°C in the presence of 5 wt% acrylic acid and 0.5 wt% Ferrous(II) sulfate as an initiator. The formed films have a homogeneous cross-linked structure.

scholarly journals Isolation and Characterization of Nanofibrillar Cellulose from Agave tequilana Weber Bagasse

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Hasbleidy Palacios Hinestroza ◽  
Javier A. Hernández Diaz ◽  
Marianelly Esquivel Alfaro ◽  
Guillermo Toriz ◽  
Orlando J. Rojas ◽  
...  
Keyword(s):  
Cellulose Nanofibers ◽  
Average Diameter ◽  
Added Value ◽  
Advanced Materials ◽  
Degree Of Crystallinity ◽  
Agave Tequilana ◽  
Force Microscopy ◽  
Nanofibrillar Cellulose ◽  
Isolation And Characterization ◽  
Atomic Force

The bagasse of Agave tequilana Weber is one of the most abundant agroindustrial wastes in the state of Jalisco. However, at the present time, there is no technical use for this waste, and its high availability makes it an environmental problem. The objective of this research was to take advantage of this waste and give it an added value to be used in the elaboration of advanced materials. In this sense, the agave bagasse cellulose was obtained using an organosolv method. To obtain the nanofibrils, the cellulose was passed through 6 cycles of a microfluidizer. The material was classified by FTIR, confirming the presence of the functional groups (O-H, C-H, C-C, and C-O-C), characteristics of cellulose, and the elimination of hemicellulose and lignin present in agave bagasse without treatment. The X-ray diffraction technique allowed the determination of the degree of crystallinity of the cellulose nanofibers, which was 68.5%, with a negative zeta potential of −42 mV. The images from the atomic force microscopy helped for the observation of the degree of fibrillation in the cellulose, and with the software ImageJ, the average diameter of the nanofibers was determined to be 75 ± 5 nm with a relatively uniform length of 1.0–1.2 μm. Finally, by means of thermogravimetric analysis, it was found that the obtained cellulose nanofibers (CNFs) supported high temperatures of thermal decomposition, so it was concluded that due to the diameter of the fibrils, the high resistance to pressure, and elasticity, the nanofibrils obtained in this investigation can be used in the elaboration of advanced materials.

Magnetic Properties of Irradiated Nickel Ferrite Thermoplastic Natural Rubber Nanocomposite

2014 ◽  
Vol 879 ◽  
pp. 206-212 ◽  
Author(s):  
Sivanesan Appadu ◽  
Sahrim Hj. Ahmad ◽  
Chantara Thevy Ratnam ◽  
Meor Yahaya Razali ◽  
Moayad Husein Flaifel ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Thermal Properties ◽  
Natural Rubber ◽  
Weight Ratio ◽  
Xrd Analysis ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Magnetic Microstructure ◽  
Sem Image ◽  
Thermoplastic Natural Rubber

The effect of electron beam (EB) irradiation at different doses on the magnetic, microstructure, morphological and thermal properties of NiFe2O4/Thermoplastic Natural Rubber (TPNR) nanocomposite was investigated. The NiFe2O4/TPNR nanocomposite samples were prepared by using a Haake mixer in weight ratio of 12:88. The TPNR matrix consists of natural rubber (NR), liquid natural rubber (LNR) and high density polyethylene (HDPE) in weight ratio of 20:10:70. The samples were irradiated using a 2 MeV EB machine in doses from 0 - 200 kGy. Magnetic properties studied by using the vibrating sample magnetometer (VSM) at room temperature showed that the values of saturation magnetization (MS), remanence magnetization (MR) and the coercivity (HC) value increased with increasing doses of irradiation. The increase in MSand MRvalues is attributed to the increase in concentration of Fe3+ions at octahedral B-site and decrease of concentration at the tetrahedral A-site in the NiFe2O4cubic structure. X-ray diffraction (XRD) analysis of the samples showed that peak intensities decreased and the width of the peaks increased with increasing doses of irradiation. Scanning electron microscope (SEM) image of the nanocomposite cross section showed the presence of defects which is more visible with increasing doses of irradiation. In the case of thermal properties, differential scanning calorimetry (DSC) analysis showed that the crystallization temperature (Tc) and the degree of crystallinity (Xc) of the nanocomposite samples decreased with increasing doses of irradiation due to crosslinking of polymeric chains which hinders the growth of crystals.

Preparation of Novel Ag/Bacterial Cellulose Hybrid Nanofibers for Antimicrobial Wound Dressing

2010 ◽  
Vol 152-153 ◽  
pp. 1771-1774 ◽  
Author(s):  
Jia Zhi Yang ◽  
Ju Wei Yu ◽  
Dong Ping Sun ◽  
Xu Jie Yang
Keyword(s):  
Bacterial Cellulose ◽  
Ag Nanoparticles ◽  
Antimicrobial Agents ◽  
Chemical Reduction ◽  
Cellulose Nanofibers ◽  
Analytical Techniques ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Hybrid Nanofibers ◽  
Transmission Electron

In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as template. Silver (Ag) nanoparticles with an average diameter of 1.5 nm were well dispersed on BC nanofibers via a simple in situ chemical-reduction between AgNO3 and NaBH4 at relatively low temperature. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by a range of analytical techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–vis absorption spectra (UV–vis). The results reveal that Ag nanoparticles were homogeneously precipitated on the BCF surface. The results indicate that Ag/BCF hybrid nanofibers are promising candidate materials for functional antimicrobial agents.

scholarly journals Photocatalytic and adsorption properties of TiO2-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

2018 ◽  
Vol 9 ◽  
pp. 364-378 ◽  
Author(s):  
Mikhail F Butman ◽  
Nikolay L Ovchinnikov ◽  
Nikita S Karasev ◽  
Nataliya E Kochkina ◽  
Alexander V Agafonov ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Nitrogen Adsorption ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
New Approach ◽  
Pillared Montmorillonite ◽  
Degussa P25 ◽  
Adsorption Desorption ◽  
High Degree

We report on a new approach for the synthesis of TiO2-pillared montmorillonite, where the pillars exhibit a high degree of crystallinity (nanocrystals) representing a mixture of anatase and rutile phases. The structures exhibit improved adsorption and photocatalytic activity as a result of hydrothermally activated intercalation of titanium polyhydroxo complexes (i.e., TiCl4 hydrolysis products) in a solution with a concentration close to the sol formation limit. The materials, produced at various annealing temperatures from the intercalated samples, were characterized by infrared spectroscopy, differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA), X-ray diffraction, dynamic light scattering (DLS) measurements, and liquefied nitrogen adsorption/desorption. The photocatalytic activity of the TiO2-pillared materials was studied using the degradation of anionic (methyl orange, MO) and cationic (rhodamine B, RhB) dyes in water under UV irradiation. The combined effect of adsorption and photocatalysis resulted in removal of 100% MO and 97.5% RhB (with an initial concentration of 40 mg/L and a photocatalyst-sorbent concentration of 1 g/L) in about 100 minutes. The produced TiO2-pillared montmorillonite showed increased photocatalytic activity as compared to the commercially available photocatalyst Degussa P25.

The Synthesis and Crystallization of Poly(vinylidene fluoride) in Supercritical CO2

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhendong Shi ◽  
Zhen Zheng ◽  
Xiaoli Su ◽  
Xinling Wang
Keyword(s):  
Vinylidene Fluoride ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Good Solubility ◽  
Poly Vinylidene Fluoride ◽  
Ft Ir ◽  
Application Fields ◽  
Crystallization Mode

AbstractA series of poly(vinylidene fluoride)s (PVDFs) is synthesized in supercritical carbon dioxide (sc-CO2). The influences of polymerization pressure, molecular weight distribution and H-H defect concentration on the crystallization of PVDF have been studied in combination with differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXRD) and Fourier transform infrared spectroscopy (FT-IR) measurements. The result shows that the morphology, molecular weights, polydispersity and head-to-head (H-H) defect concentrations of the PVDFs are affected by the reaction pressure and good solubility generated from sc-CO2. Especially, the sc-CO2 polymerization has greatly improved the crystallization mode of the obtained PVDFs such as the complete degree of crystallinity, crystallinity and the crystal phase. This will create more comprehensive application fields for PVDF.

Extraction of Bamboo Nanofibers Using Acid Hydrolysis for Functional Chemicals of Ecological Dyeing and Finishing

2012 ◽  
Vol 441 ◽  
pp. 759-763 ◽  
Author(s):  
Yong Zhang ◽  
Guo Xin Xue ◽  
Xiu Mei Zhang ◽  
Yan Jun Tang
Keyword(s):  
Acid Hydrolysis ◽  
Cellulose Nanofibers ◽  
Average Diameter ◽  
Degree Of Polymerization ◽  
X Ray Diffraction ◽  
Surface Charges ◽  
Aggregation State ◽  
Transmission Electron ◽  
Different Types ◽  
Bamboo Fibers

In this work a study on the feasibility of extracting cellulose nanofibers from bamboo fibers, by means of three different procedures was carried out. These processes included the using of three different types of acids (H2SO4, HCl, and a mixture of H2SO4/HCl). The raw bamboo fibers were mercerized with NaOH solutions. They were then submitted to the three different acid hydrolysis processes. The final bamboo nanofibers were morphologically characterized by transmission electron microscopy (TEM) and their surface charges in suspensions were estimated by Zeta-potential. Their degree of polymerization (DP) was characterized by viscometry and the crystallinity was tested by X-ray diffraction (XRD). All bamboo nanofibers presented a rod-like shape, an average diameter (D) of 6-10 nm and length (L) of 100-180 nm, with an aspect ratio (L/D) of around 16-18. The aggregation state increases with the amount of HCl introduced into the extraction, due to the decrease of surface charges. However, this release presented nanofibers with litter better degree of polymerization than those whose acid hydrolysis was carried out using only H2SO4.

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