scholarly journals Xylan-Derived Light Conversion Nanocomposite Film

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1779
Author(s):  
Yunyi Yang ◽  
Yushuang Zhao ◽  
Yijie Hu ◽  
Xinwen Peng ◽  
Linxin Zhong

A new type of sustainable light conversion nanocomposite film was fabricated by using carboxymethyl xylan as matrix and xylan-derived carbon dots (CDs) as both light conversion regents and nano reinforcements. The results demonstrate that CDs can not only significantly enhance the mechanical strength of the nanocomposite film because of chemical reaction between CDs and carboxymethyl xylan, but also impart the film with excellent optical properties. With 1.92 wt% CDs, the tensile strength and elastic modulus of the film are increased by 114.3% and 90.7%, respectively. Moreover, the film has typical excitation and emission spectra, enabling the efficient absorption of UV and the conversion of UV to blue light. This xylan-derived light conversion nanocomposite film is expected to be used in agricultural planting and food packaging.

Author(s):  
Arini Ulfah M.R ◽  
Syahrul Humaidi ◽  
Kurnia Sembiring

Biofoam material has been made for application of styrofoam substitute food packaging material from a mixture of raw materials: taro leaf powder and PVAc through a hot compaction method with variations of the composition of taro leaf powder: PVAc (80:20)% wt, (75:25)% wt, (70 : 30)% wt, (65:35) wt%, (60:40) wt%, (55:45)% wt, (50:50)% wt and (45:50)% wt. The first stage of taro leaves was blended and sifted with 100 mesh particle size. The second stage of the leaf powder of taro mixed with wet mixing was then mixed with PVAc as a matrix. The third stage of the homogeneous mixture was then put into the mold then compressed by heat to make it more dense with a pressure of 100 MPa and held for 10 minutes at 60 oC. Each biofoam sample that is ready to be characterized includes: physical properties (density, water absorption, functional groups and biodegredability), mechanical properties (tensile strength, elastic modulus, and elongation) and thermal properties (melting points). The characterization results showed that taro leaf powder: the optimum PVAc was (45: 55) wt% with a density value of 0.744 x 103 kg/m3, water absorption capacity of 1.765%, composed of OH and CH groups of PVAc and cellulose and C = C groups of lignin so that it has degrading properties of 91.2% for 50 days. Mechanical properties with tensile strength of 0.357 MPa, elastic modulus of 1.449 MPa, and elongation of 246.416%. Thermal properties with a melting point of 350.21 oC whose results have met the standards of conventional brand Synbra Technology. The results of biofoam material based on composite taro leaves and PVAc can be applied as food packaging.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3367
Author(s):  
Xiaowei Xu ◽  
Jie Pang

In order to enforce the mechanical strength and antibacterial ability of biofilm and explore the underlying mechanism, sodium lignosulfonate (SL) and ε-polylysine (ε-PL) were introduced to fabricate the composite film of konjac glucomannan (KGM)/SL/ε-PL in the present study. According to our previous method, 1% (w/v) of KGM was the optimal concentration for the film preparation method, on the basis of which the amount of SL and ε-PL were screened by mechanical properties enforcement of film. The structure, mechanical performance and thermal stability of the film were characterized by SEM, FTIR, TGA and tensile strength tests. The optimized composite film was comprised of KGM 1% (w/v), SL 0.2% (w/v), and ε-PL 0.375% (w/v). The tensile strength (105.97 ± 4.58 MPa, p < 0.05) and elongation at break (95.71 ± 5.02%, p < 0.05) of the KGM/SL/ε-PL composite film was greatly improved compared with that of KGM. Meanwhile, the thermal stability and antibacterial property of film were also enhanced by the presence of SL and ε-PL. In co-culturation mode, the KGM/SL/ε-PL composite film showed good inhibitory effect on Escherichia coli (22.50 ± 0.31 mm, p < 0.05) and Staphylococcus aureus (19.69 ± 0.36 mm, p < 0.05) by determining the inhibition zone diameter. It was revealed that KGM/SL/ε-PL composite film shows enhanced mechanical strength and reliable antibacterial activities and it could be a potential candidate in the field of food packaging.


Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Vladislav Zadorozhnyy ◽  
Sergey V. Ketov ◽  
Takeshi Wada ◽  
Stefan Wurster ◽  
Vignesh Nayak ◽  
...  

Rising demand for bone implants has led to the focus on future alternatives of alloys with better biocompatibility and mechanical strength. Thus, this research is dedicated to the synthesis and investigation of new compositions for low-alloyed Ti-based compounds, which conjoin relatively acceptable mechanical properties and low elastic moduli. In this regard, the structural and mechanical properties of α + β Ti-Fe-Cu-Sn alloys are described in the present paper. The alloys were fabricated by arc-melting and tilt-casting techniques which followed subsequent thermo-mechanical treatment aided by dual-axial forging and rolling procedures. The effect of the concentrations of the alloying elements, and other parameters, such as regimes of rolling and dual-axial forging operation, on the microstructure and mechanical properties were thoroughly investigated. The Ti94Fe1Cu1Sn4 alloy with the most promising mechanical properties was subjected to thermo-mechanical treatment. After a single rolling procedure at 750 °C, the alloy exhibited tensile strength and tensile plasticity of 1300 MPa and 6%, respectively, with an elastic modulus of 70 GPa. Such good tensile mechanical properties are explained by the optimal volume fraction balance between α and β phases and the texture alignment obtained, providing superior alternatives in comparison to pure α- titanium alloys.


2018 ◽  
Vol 2 (2) ◽  
pp. 43
Author(s):  
Permono Adi Putro ◽  
Liszulfah Roza ◽  
Isnaeni Isnaeni

<p class="Abstract">Carbon dots (C-dots) are a new type of fluorescent nanoparticles that can be readily synthesized from natural sources, such as cassava’s peels. In this work, C-dots were synthesized from cassava’s peels using low temperature green synthesis based. The Green synthesis techniques were done by using water as a solvent non-chemical and natural sources. The Synthesis was done using various concentrations of precursor from 0.25%, 0.50%, 1.0% and 2.0%. Optical properties of C-dots were characterized using spectrophotometer UV-Vis, photoluminescence (PL) and time resolved photoluminescence (TRPL). The concentration of precursor lead to differences in molecular density and content of preparation thus affecting optical properties. The performance of C-dots optical properties were dominated by the transition of electrons n–π* on structure aromtic C=O which originate from the surface of C-dots. The result of C-dots sample with a concentration of 2.0% precursors has the best emission effiency. This provides the potential for C-dots cassava’s peels in the aqueous solution to be applied as cellular bioimaging and biosensing metal ions and salts.</p>


2014 ◽  
Vol 6 (1) ◽  
pp. 27 ◽  
Author(s):  
Desi Mustika Amaliyah

Durian (Durio zibethinus) and cempedak (Artocarpus integer) peels waste are not used by the society. The research aim is to extract pectin from durian and cempedak peels and to formulate the pectin into edible films for food packaging. The research stages were first pre-treatment of durian and cempedak peels, pectin extraction, pectin drying, and  pectin application as edible films with concentration of 0%, 5%, and 15%. Based on this research it was concluded that pectin can be extracted from durian and cempedak peels with yield result of 27.97 % and 55.58 %, respectively. Edible film obtained has  similar characteristics between raw materials cempedak and durian peels. The higher concentration of cempedak peel  pectin increased the thickness, but decreased the tensile strength and elongation at a concentration of 15%. While in edible films from durian peel pectin, the higher concentration of pectin decreased the thickness of edible film on pectin concentration of 15%, lowered tensile strength and raised the edible film elongation.Keywords: waste, durian, cempedak, pectin extraction, edible film


2020 ◽  
Vol 25 (46) ◽  
pp. 4848-4860 ◽  
Author(s):  
Anisha Anand ◽  
Gopinathan Manavalan ◽  
Ranju Prasad Mandal ◽  
Huan-Tsung Chang ◽  
Yi-Ru Chiou ◽  
...  

: The prevention and treatment of various infections caused by microbes through antibiotics are becoming less effective due to antimicrobial resistance. Researches are focused on antimicrobial nanomaterials to inhibit bacterial growth and destroy the cells, to replace conventional antibiotics. Recently, carbon dots (C-Dots) become attractive candidates for a wide range of applications, including the detection and treatment of pathogens. In addition to low toxicity, ease of synthesis and functionalization, and high biocompatibility, C-Dots show excellent optical properties such as multi-emission, high brightness, and photostability. C-Dots have shown great potential in various fields, such as biosensing, nanomedicine, photo-catalysis, and bioimaging. This review focuses on the origin and synthesis of various C-Dots with special emphasis on bacterial detection, the antibacterial effect of CDots, and their mechanism.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 228
Author(s):  
Swarup Roy ◽  
Lindong Zhai ◽  
Hyun Chan Kim ◽  
Duc Hoa Pham ◽  
Hussein Alrobei ◽  
...  

A chitosan-based nanocomposite film with tannic acid (TA) as a cross-linker and titanium dioxide nanoparticles (TiO2) as a reinforcing agent was developed with a solution casting technique. TA and TiO2 are biocompatible with chitosan, and this paper studied the synergistic effect of the cross-linker and the reinforcing agent. The addition of TA enhanced the ultraviolet blocking and mechanical properties of the chitosan-based nanocomposite film. The reinforcement of TiO2 in chitosan/TA further improved the nanocomposite film’s mechanical properties compared to the neat chitosan or chitosan/TA film. The thermal stability of the chitosan-based nanocomposite film was slightly enhanced, whereas the swelling ratio decreased. Interestingly, its water vapor barrier property was also significantly increased. The developed chitosan-based nanocomposite film showed potent antioxidant activity, and it is promising for active food packaging.


2021 ◽  
pp. 100435
Author(s):  
Yan Wang ◽  
Noura Dawas Alkhaldi ◽  
Nil Kanatha Pandey ◽  
Lalit Chudal ◽  
Lingyun Wang ◽  
...  

2021 ◽  
Author(s):  
Alagan Muthurasu ◽  
V GANESH

Carbon dots (CDs) exhibiting fluorescence property are generally derived from carbonaceous materials and possessing ultra small size with various exciting physical, chemical and photo-properties that have been used in many...


Cellulose ◽  
2021 ◽  
Vol 28 (15) ◽  
pp. 9751-9768
Author(s):  
Teija Laukala ◽  
Sami-Seppo Ovaska ◽  
Ninja Kerttula ◽  
Kaj Backfolk

AbstractThe effects of bio-based strengthening agents and mineral filling procedure on the 3D elongation of chemi-thermomechanical pulp (CTMP) handsheets with and without mineral (PCC) filling have been investigated. The 3D elongation was measured using a press-forming machine equipped with a special converting tool. The strength of the handsheets was altered using either cationic starch or microfibrillated cellulose. Precipitated calcium carbonate (PCC) was added to the furnish either as a slurry or by precipitation of nano-sized PCC onto and into the CTMP fibre. The 3D elongation of unfilled sheets was increased by the dry-strengthening agents, but no evidence on the theorised positive effect of mineral fill on 3D elongation was seen in either filling method. The performance of the strengthening agent depended on whether the PCC was as slurry or as a precipitated PCC-CTMP. The starch was more effective with PCC-CTMP than when the PCC was added directly as a slurry to the furnish, whereas the opposite was observed with microfibrillated cellulose. The 3D elongation correlated positively with the tensile strength, bursting strength, tensile stiffness, elastic modulus and bending stiffness, even when the sheet composition was varied, but neither the strengthening agent nor the method of PCC addition affected the 3D elongation beyond what was expectable based on the tensile strength of the sheets. Finally, mechanisms affecting the properties that correlated with the 3D elongation are discussed.


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