scholarly journals Effect of H2O2 Bleaching Treatment on the Properties of Finished Transparent Wood

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 776 ◽  
Author(s):  
Yan Wu ◽  
Jiamin Wu ◽  
Feng Yang ◽  
Caiyun Tang ◽  
Qiongtao Huang
Keyword(s):  
Treatment Time ◽  
Lignin Content ◽  
Optical Transmittance ◽  
Sem Analysis ◽  
Wood Products ◽  
Ft Ir ◽  
Polymer Impregnation ◽  
Micro Structures ◽  
Bleaching Treatment ◽  
Wood Template

Transparent wood samples were fabricated from an environmentally-friendly hydrogen peroxide (H2O2) bleached basswood (Tilia) template using polymer impregnation. The wood samples were bleached separately for 30, 60, 90, 120 and 150 min to evaluate the effects on the changes of the chemical composition and properties of finished transparent wood. Experimental results showed decreases in cellulose, hemicellulose, and lignin content with an increasing bleaching time and while decreasing each component to a unique extent. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) analysis indicated that the wood cell micro-structures were maintained during H2O2 bleaching treatment. This allowed for successful impregnation of polymer into the bleached wood template and strong transparent wood products. The transparent wood possessed a maximum optical transmittance up to 44% at 800 nm with 150 min bleaching time. Moreover, the transparent wood displayed a maximum tensile strength up to 165.1 ± 1.5 MPa with 90 min bleaching time. The elastic modulus (Er) and hardness (H) of the transparent wood samples were lowered along with the increase of H2O2 bleaching treatment time. In addition, the transparent wood with 30 min bleaching time exhibited the highest Er and H values of 20.4 GPa and 0.45 GPa, respectively. This findings may provide one way to choose optimum degrees of H2O2 bleaching treatment for transparent wood fabrication, to fit the physicochemical properties of finished transparent wood.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

Pemanfaatan Cangkang Pensi (Corbicula Moltkiana) sebagai Bahan Penyerap Zat Warna Rhodamin B Dalam Larutan

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Rahmiana Zein ◽  
Mutia Khuratul Aini ◽  
Hermansyah Aziz
Keyword(s):  
Rhodamine B ◽  
Sem Analysis ◽  
Spectra Analysis ◽  
Biosorption Capacity ◽  
Biosorption Process ◽  
Langmuir Isotherm Model ◽  
Ft Ir ◽  
Cationic Exchange ◽  
Rhodamin B ◽  
Model Isotherm

Biosorpsi zat warna Rhodamine B menggunakan cangkang Pensi (Corbicula moltkiana) telah dikaji. Percobaan dilakukan dengan system batch guna memperoleh kondisi optimum biosorspi zat warna. Kapasitas biosorpsi zat warna pada pH 2 adalah 0.9958 mg/g, dengan konsentrasi larutan mula-mula 150 mg/L waktu kontak 105 menit, massa biosorben 0.1 g, ukuran partikel 32 µm dan temperature pengeringan biosorben pada 75oC. Model isotherm Langmuir menunjukkan bahwa proses penyerapan berlangsung secara kimia dan biosorpsi homogeny dari adsorbat (Rhodamine B) pada permukaan biosorben membentuk lapisan tunggal dengan nilai R2 0.9966. Analisis XRF menunjukkan bahwa penurunan kadar unsur logam pada cangkang Pensi membuktikan bahwa proses biosorpsi berlangsung dengan pertukaran kation. Hasil analisis spektrum FT-IR membuktikan adanya interaksi antaramolekul Rhodamin B dengan gugus fungsi pada cangkang Pensi. Analisis dengan SEM memperlihatkan bahwa pori-pori cangkang Pensi telah terisi penuh oleh molekul Rhodamin B. Kondisi optimum biosorpsi telah diaplikasikan pada limbah kerupuk merah dengan kapasitas penyerapan sebesar 0,2835 mg/g.   The biosorption of Rhodamine B dyes by Pensi (Corbicula moltkiana) shell has been investigated. The experiment was conducted in batch sistem in order to obtain the optimum conditions of dye biosorption. Biosorption capacity of dye was 0.9958 mg/g at pH 2, initial concentration 150 mg/L, contact time 105 minutes, biosorbent mass 0.1 gram, particle size 32 µ m and biosorbent drying temperature was at 75oC. The Langmuir Isotherm model showed chemisorption and homogeneous biosorption process of adsorbates onto the biosorbent surface formed monolayer dye molecules on the biosorbent surface with R2 value was 0.9966. XRF analysis showed that reduction of metals unsure quantity of pensi shell indicated biosorption process was occupied through cationic exchange. The result of FTIR spectra analysis indicated an interaction between Rhodamin B molecules and functional group of pensi shell. SEM analysis showed that the pensi shell pores were completely filled by Rhodamine B molecules. The optimum condition of biosorption has been aplicated in red chips wastewater industry with biosorption capacity was 0.2835 mg/g.

scholarly journals Incorporation of silver stearate nanoparticles in methacrylate polymeric monoliths for hemeprotein isolation

2020 ◽  
Vol 18 (1) ◽  
pp. 399-411
Author(s):  
Eman Alzahrani
Keyword(s):  
Noble Metals ◽  
Extraction Process ◽  
Sem Analysis ◽  
X Ray ◽  
Polymeric Scaffold ◽  
Extended Surface ◽  
Unique Method ◽  
Unique Approach ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

AbstractA unique method was used to synthesize extremely stable silver stearate nanoparticles (AgStNPs) incorporated in an organic-based monolith. The facile strategy was then used to selectively isolate hemeproteins, myoglobin (Myo) and hemoglobin (Hb). Ethyl alcohol, silver nitrate, and stearic acid were, respectively, utilized as reducing agents, silver precursors, and capping agents. The color changed to cloudy from transparent, indicating that AgStNPs had been formed. AgStNP nanostructures were then distinctly integrated into the natural polymeric scaffold. To characterize the AgStNP–methacrylate polymeric monolith and the silver nanoparticles, energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), and Fourier-transform infrared (FT-IR) spectroscopy were used. The results of the SEM analysis indicated that the AgStNP–methacrylate polymeric monolith’s texture was so rough in comparison with that of the methacrylate polymeric monolith, indicating that the extraction process of the monolith materials would be more efficient because of the extended surface area of the absorbent. The comparison between the FT-IR spectra of AgStNPs, the bare organic monolith, and AgStNP–methacrylate polymeric monolith confirms that the AgStNPs were immobilized on the surface of the organic monolith. The EDX profile of the built materials indicated an advanced peak of the Ag sequence which represented an Ag atom of 3.27%. The results therefore established that the AgStNPs had been successfully integrated into the monolithic materials. Extraction efficiencies of 92% and 97% were used to, respectively, recover preconcentrated Myo and Hb. An uncomplicated method is a unique approach of both fabrication and utilization of the nanosorbent to selectively isolate hemeproteins. The process can further be implemented by using other noble metals.

Synthesis and Characterization of Silver Nanoparticles from Psidium Guajava Leaf Extract

2021 ◽  
Vol 14 (5) ◽  
pp. 5634-5638
Author(s):  
Sruthi Radhakrishnan
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Leaf Extract ◽  
Nanoparticle Synthesis ◽  
Ethanolic Extract ◽  
Psidium Guajava ◽  
Sem Analysis ◽  
Synthesis Of Nanoparticles ◽  
Elemental Silver ◽  
Ft Ir

Green route for the synthesis of nanoparticles has become more acceptable than the other chemical as well as biological route. In the present study, silver nanoparticle is synthesized using ethanolic extract of Psidium guajava leaves. Further the synthesized silver nanoparticles were characterized by UV-Visible Spec, FT-IR, X-Ray Diffraction FESEM and E-DAX. The results of FT-IR provided evidence of the involvement of phytochemicals present in the leaf extract in the reduction of silver nitrate to silver nanoparticles. XRD confirmed the crystalline structure as well as shape of the synthesized nanoparticle as face-centred cubic. E-DAX profiling helped in determining the presence of elemental silver. The size of the nanoparticle procured by SEM analysis was found to be approximately 30-50 nm in size. Thus, the findings of this study showed that the plant assisted method for silver nanoparticle synthesis is more effective and further application level studies can shed lights on their use in healing of various human ailments.   

scholarly journals Effects of Gum Arabic-Coated Magnetite Nanoparticles on the Removal of Pb Ions from Aqueous Solutions

2021 ◽  
pp. 889-896
Author(s):  
Hanan J. Mustafa ◽  
Tagreed M. Al-Saadi
Keyword(s):  
Aqueous Solutions ◽  
Crystallite Size ◽  
Magnetite Nanoparticles ◽  
Gum Arabic ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Absorption Bands ◽  
X Ray ◽  
Ft Ir ◽  
Pb Ions

To study the removal of lead (Pb) ions from aqueous solutions, novel magnetite nanoparticles (NPs) of Ni0.31Mg0.15Ag0.04Fe2.5O4 were synthesized by coprecipitation synthesis using metal sulfates, and then coated with Gum Arabic (GA). The prepared NPs were analyzed using various spectroscopic and analytical methods, such as X-Ray diffraction analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infra-Red spectroscopy (FT-IR), and Atomic Absorption Spectrophotometer (AAS). By using XRD analysis, the cubic inverse spinel structure of the prepared NPs was proven, showing average values of crystallite size, lattice constant, and density of 28.57nm, 8.32582Å, and 5.2890 g/cm3, respectively. FE-SEM analysis revealed the sphere-like shape of the nanoparticles with a measured crystallite size of 25.93nm. The existence of constituent elements was evidenced by EDX. FT-IR test proved the success of the coating process of magnetite NPs by the presence of the main characteristic absorption bands of GA in the FT-IR spectrum of GA-magnetite NPs. The adsorption of Pb ions by GA- magnetite NPs was shown by AAS analysis, where the concentration of Pb ions decreased from 25ppm to 6.6ppm, reaching 1.1ppm at the time of 25min. The porosity of the NPs and the carboxyl groups in GA played an important role in the process.

scholarly journals Preparations of Poly(lactic acid) Dispersions in Water for Coating Applications

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2767
Author(s):  
Giada Belletti ◽  
Sara Buoso ◽  
Lucia Ricci ◽  
Alejandro Guillem-Ortiz ◽  
Alejandro Aragón-Gutiérrez ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Gel Permeation Chromatography ◽  
Sem Analysis ◽  
Water Phase ◽  
Poly Lactic Acid ◽  
Water Emulsion ◽  
Preparation Conditions ◽  
Ft Ir ◽  
Homogenization Methods ◽  
Oil In Water Emulsion

A green, effective methodology for the preparation of water-based dispersions of poly(lactic acid) (PLA) for coating purposes is herein presented. The procedure consists of two steps: in the first one, an oil-in-water emulsion is obtained by mixing a solution of PLA in ethyl acetate with a water phase containing surfactant and stabilizer. Different homogenization methods as well as oil/water phase ratio, surfactant and stabilizer combinations were screened. In the second step, the quantitative evaporation of the organic provides water dispersions of PLA that are stable, at least, over several weeks at room temperature or at 4 °C. Particle size was in the 200–500 nm range, depending on the preparation conditions, as confirmed by scanning electron microscope (SEM) analysis. PLA was found not to suffer significant molecular weight degradation by gel permeation chromatography (GPC) analysis. Furthermore, two selected formulations with glass transition temperature (Tg) of 51 °C and 34 °C were tested for the preparation of PLA films by drying in PTFE capsules. In both cases, continuous films that are homogeneous by Fourier-transform infrared spectroscopy (FT-IR) and SEM observation were obtained only when drying was performed above 60 °C. The formulation with lower Tg results in films which are more flexible and transparent.

Surface Treatment of PMIA Fibers with Sub-Atmospheric Pressure Dielectric Barrier Glow Discharge Plasma

2014 ◽  
Vol 1048 ◽  
pp. 72-76
Author(s):  
Huan Da Zheng ◽  
Juan Zhang ◽  
Bing Du ◽  
Qu Fu Wei ◽  
Lai Jiu Zheng
Keyword(s):  
Glow Discharge ◽  
Atmospheric Pressure ◽  
Chemical Structure ◽  
Surface Characterization ◽  
Discharge Plasma ◽  
Treatment Time ◽  
Fiber Surface ◽  
Glow Discharge Plasma ◽  
Dielectric Barrier ◽  
Ft Ir

Meta-aramid fibers were treated by sub-atmospheric pressure dielectric barrier glow discharge plasma. The effect of plasma treatment time on the fiber surface physical and chemical properties was studied by using surface characterization techniques. Scanning electron microscopy (SEM) was performed to determine the surface morphology changes. FT-IR spectroscopy measurements were performed to investigate the change of chemical structure. Dynamic contact angle analysis (DCAA) was used to examine the changes of the fiber surface wettability. SEM analysis showed that there was obvious crack along the fibers’ axial direction present on the fiber surface, which resulted in the better wetting behavior of the plasma-treated PMIA fiber. FT-IR analysis showed that plasma had little effect on the chemical structure of PMIA fibers. DCAA analysis showed that the wettability of the samples could be improved with the treatment time increasing. In addition, a slight decrease in breaking strength was observed at the treatment time ranging from 60 to 180 s in comparison with the untreated sample.

scholarly journals Transcrystallization of Isotactic Polypropylene/Bacterial Cellulose Hamburger Composite

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 508 ◽  
Author(s):  
Bo Wang ◽  
Fu-hua Lin ◽  
Xiang-yang Li ◽  
Xu-ran Ji ◽  
Si-xiao Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bacterial Cellulose ◽  
Isotactic Polypropylene ◽  
Crystallization Rate ◽  
Sem Analysis ◽  
Hydroxyl Groups ◽  
Hot Press ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Fourier Transform

Isotactic polypropylene (iPP) is a commonly used thermoplastic polymer with many excellent properties. But high brittleness, especially at low temperatures, limits the use of iPP. The presence of transcrystallization of iPP makes it possible for fiber-reinforced iPP composites with higher strength. Bacterial cellulose (BC) is a kind of cellulose with great potential to be used as a new filler to reinforce iPP due to its high crystallinity, biodegradability and efficient mechanical properties. In this study, the iPP/BC hamburger composite was prepared by a simple hot press and maleic anhydride grafted polypropylene (MAPP) was used to improve the interface compatibility of iPP and BC. The polarizing microscope (POM) photograph shows that BC successfully induces the transcrystallization of iPP. The differential Scanning Calorimeter (DSC) date proves that the addition of BC could improve the thermal properties and crystallization rate of the composite. Especially, this change is more obvious of the iPP/MAPP/BC. The mechanical properties of the iPP/BC composites were greatly increased. This DSC date is higher than BC; we used BC particles to enhance the iPP in our previous research. The scanning Electron Microscope (SEM) analysis intuitively shows that the interface of the iPP/MAPP/BC is more smooth and flat than the iPP/BC. The fourier Transform infrared spectroscopy (FT-IR) analysis of the iPP/BC hamburger composites was shown that a new C=O group vibration appeared at 1743 cm−1, which indicated that the hydrogen bond structure of BC molecules was weakened and some hydroxyl groups were substituted after modification which can increase the lipophilicity of BC. These results indicated that the BC fiber can easily induce the transcrystallization of iPP, which has excellent mechanical properties. Moreover, the addition of MAPP contributes greatly to the interface compatibility of iPP and BC.

The effects of thermal treatment on the nanomechanical behavior of bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) cell walls observed by nanoindentation, XRD, and wet chemistry

Holzforschung ◽  
2017 ◽  
Vol 71 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Yanjun Li ◽  
Chengjian Huang ◽  
Li Wang ◽  
Siqun Wang ◽  
Xinzhou Wang
Keyword(s):  
Cell Wall ◽  
Thermal Treatment ◽  
Cell Walls ◽  
Treatment Time ◽  
Lignin Content ◽  
Phyllostachys Pubescens ◽  
X Ray Diffraction ◽  
Wet Chemistry ◽  
X Ray ◽  
Wet Chemical

Abstract The effects of thermal treatment of bamboo at 130, 150, 170, and 190°C for 2, 4, and 6 h were investigated in terms of changes in chemical composition, cellulose crystallinity, and mechanical behavior of the cell-wall level by means of wet chemical analysis, X-ray diffraction (XRD), and nanoindentation (NI). Particularly, the reduced elastic modulus (Er), hardness (H), and creep behavior were in focus. Both the temperature and treatment time showed significant effects. Expectedly, the hemicelluloses were degraded and the relative lignin content was elevated, while the crystallinity of the cellulose moiety was increased upon thermal treatment. The Er and H data of the cell wall were increased after 6 h treatment at 190°C, from 18.4 to 22.0 GPa and from 0.45 to 0.65 GPa, respectively. The thermal treatment led to a decrease of the creep ratio (CIT) under the same conditions by ca. 28%. The indentation strain state (εi) also decreased significantly after thermal treatment during the load-holding stage.

scholarly journals Microfibrillated lignocellulose (MFLC) and nanopaper films from unbleached kraft softwood pulp

Cellulose ◽  
2019 ◽  
Vol 27 (4) ◽  
pp. 2325-2341 ◽  
Author(s):  
Erfan Oliaei ◽  
Pär A. Lindén ◽  
Qiong Wu ◽  
Fredrik Berthold ◽  
Lars Berglund ◽  
...  
Keyword(s):  
Lignin Content ◽  
Optical Transmittance ◽  
Distribution Data ◽  
Total Charge ◽  
Strongly Correlated ◽  
Water Contact ◽  
Material Component ◽  
Softwood Pulp ◽  
Tem Microscopy ◽  
Wood Pulp Fibre

Abstract Microfibrillated cellulose (MFC) is an important industrial nanocellulose product and material component. New MFC grades can widen the materials property range and improve product tailoring. Microfibrillated lignocellulose (MFLC) is investigated, with the hypothesis that there is an optimum in lignin content of unbleached wood pulp fibre with respect to nanofibril yield. A series of kraft fibres with falling Kappa numbers (lower lignin content) was prepared. Fibres were beaten and fibrillated into MFLC by high-pressure microfluidization. Nano-sized fractions of fibrils were separated using centrifugation. Lignin content and carbohydrate analysis, total charge, FE-SEM, TEM microscopy and suspension rheology characterization were carried out. Fibres with Kappa number 65 (11% lignin) combined high lignin content with ease of fibrillation. This confirms an optimum in nanofibril yield as a function of lignin content, and mechanisms are discussed. MFLC from these fibres contained a 40–60 wt% fraction of nano-sized fibrils with widths in the range of 2.5–70 nm. Despite the large size distribution, data for modulus and tensile strength of MFLC films with 11% lignin were as high as 14 GPa and 240 MPa. MFLC films showed improved water contact angle of 84–88°, compared to neat MFC films (< 50°). All MFLC films showed substantial optical transmittance, and the fraction of haze scattering strongly correlated with defect content in the form of coarse fibrils. Graphic abstract

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