scholarly journals The influence of culture medium components on the physical and mechanical properties of cellulose synthesized by kombucha microorganisms

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3125-3135 ◽  
Author(s):  
Izabela Betlej ◽  
Renata Salerno-Kochan ◽  
Krzysztof J. Krajewski ◽  
Janusz Zawadzki ◽  
Piotr Boruszewski

Preliminary studies are presented showing to what extent nutrients available in the growth environment of Kombucha microorganisms affect the physical and mechanical properties of synthesized cellulose. With an increase in the amount of sucrose in the growth medium and with the presence of additional nutrients, peptone and tea extract, the thickness and strength of the biopolymer increased, while elongation was reduced. The best physical and mechanical parameters were obtained for bacterial cellulose from cultures with the addition of 10% sucrose and 0.25% peptone content. The increase in elongation correlated with the decrease in the degree of polymerization, which means that in media rich in nutrients, the number of molecules building the polymer decreases. The presented data is important in order to select ingredients that will help synthesize bacterial cellulose with the desired physio-mechanical properties.

2021 ◽  
Vol 50 (2) ◽  
pp. 493-505
Author(s):  
Izabela Betlej ◽  
Sarani Zakaria ◽  
Krzysztof J. Krajewski ◽  
Piotr Boruszewski

This review paper is related to the utilization on bacterial cellulose in many applications. The polymer produced from bacterial cellulose possessed a very good physical and mechanical properties, such as high tensile strength, elasticity, absorbency. The polymer from bacterial cellulose has a significantly higher degree of polymerization and crystallinity compared to those derived from plant. The collection of selected literature review shown that bacterial cellulose produced are in the form pure cellulose and can be used in many of applications. These include application in various industries and sectors of the economy, from medicine to paper or electronic industry.


2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.


2021 ◽  
Vol 63 (4) ◽  
pp. 385-391
Author(s):  
T. K. Meleshko ◽  
A. B. Razina ◽  
N. N. Bogorad ◽  
M. P. Kurlykin ◽  
A. V. Kashina ◽  
...  

Abstract New polymer brushes with an ester backbone and poly(methyl methacrylate) side chains are synthesized by polycondensation and polymerization methods. The initiating groups are sulfonyl chloride groups laterally attached to the polyester chain. PMMA side chains are grafted by the ATRP method according to the “grafting from” multicenter macroinitiator strategy. The conditions for the polymerization processes in a controlled mode are selected, and the ways of targeted regulation of the degree of polymerization of methacrylate side chains are determined. Using the synthesized copolymers self-supporting films are obtained, and their physical and mechanical properties are studied.


2019 ◽  
Vol 106 ◽  
pp. 01023
Author(s):  
Justyna Morman-Wątor

The article presents the results of tests for mining waste mixtures - cement. The addition of cement was aimed at limiting the leaching of fine particles and improving physical and mechanical parameters. The studies used cement CEM I 42.5 R and CEM III/ A 42.5N - LH / HSR / NA and plasticizing sealant. The paper presents the results of freeze resistance, swelling tests, pH of water leachate and oedometer soil testing.


2003 ◽  
Vol 125 (4) ◽  
pp. 288-292 ◽  
Author(s):  
Zhijun Li ◽  
Yongxue Wang ◽  
Xiwen Wang ◽  
Guangwei Li

The effects of cement content and curing period on a new synthetic model ice, DUT-1, are reported. The cement (450#) contents were 10%, 11%, 12%, 13%, 14%, 15% and 16% by dry weight of mixture material. Eight different curing periods were used: 66 h, 92 h, 115 h, 139 h, 163 h, 186 h, 211 h and 235 h. Physical and mechanical properties, such as density, compressive strength, flexural strength, and elastic modulus, were determined. The density and mechanical parameters were found to increase with increasing cement content, whereas the durations of curing period under normal air temperature resulted in increasing these properties to a maximum value, then decreasing values.


Author(s):  
Yurii Polievoda ◽  
Igor Tverdokhlib

The information about growing and processing of walnut in Europe and Ukraine is given. The actuality of the implementation of peeling, maximally preserved nuts is established. Based on the conducted research, the physical and mechanical properties of walnut shell are determined. The rational energy indices of the peeling process are found at maximum preservation of the fetus. The use of the developed equipment for preliminary peeling of the walnut in order to get microcracks is proposed.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Ji-jing Wang ◽  
Zhen-ning Shi ◽  
Ling Zeng ◽  
Shuang-xing Qi

In order to analyze the influence of different nanoadditives on the physical and mechanical properties of similar silty mudstone materials, nano-TiO2 (NTi), nano Al2O3 (NAl), and nanobentonite (NBe) were added to improve the physical and mechanical properties of silty mudstone similar materials. The physical and mechanical parameters are more in line with silty rock. Finally, nanometer additives suitable for silty mudstone similar materials are determined by conducting density test, natural water absorption test, uniaxial compression test, splitting test, softening coefficient test, expansibility test, and microscopic test. The effects of adding NTi, NAl, and NBe on improving the physical and mechanical properties of silty mudstone similar materials were studied to analyze the influence law of different NTi, NAl, and NBe contents on similar material density, natural water absorption, uniaxial compressive strength, tensile strength, softening coefficient, expansion rate, and other physical and mechanical parameters. The microscopic morphology of similar materials was analyzed by scanning electron microscopy and the mechanism of influence of nanoadditives on the microscopic structure of samples was revealed. The results are as follows. (1) The density of similar materials of silty mudstone increases with the increase of the content of nanoadditive. The natural water absorption rate decreased first and then increased with the increase of the content of nanometer additives, while the softening coefficient decreased with the increase of the content of nanometer additives. The uniaxial compressive strength and tensile strength increased first and then decreased with the increase of the content of nanometer additives. This is due to the incorporation of the nanoadditive amount effective to promote the hydration reaction of gypsum and accelerate the production of cement, while a similar material may be filled in the pores, reducing the internal defects, a similar material to make denser; when excessive dosage, nanoadditives agglomeration occurs, resulting in deterioration of the effect, but will reduce the mechanical properties of similar materials. (2) When the content of NBe is 6%, the physical and mechanical parameters of similar materials can reach or be closer to the silty raw rock except uniaxial compressive strength. The failure mode of the uniaxial compression specimen is also the same as that of the original rock, which can be used as the best choice. The research results laid the foundation for further analysis of NBe application in similar materials.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jagat Kumar Shrestha ◽  
Sujit Bhandari

Masonry walls with distinct layers, known as multi-leaf masonry walls, are prevalent in many regions of the world including ancient architecture in Europe and new construction in the Himalayan region of South Asia. This paper presents a model for determining the capacity of multi-leaf stone masonry wall from its physical and mechanical parameters. For the study, a “Standard Wall” with typical properties of a multi-leaf stone masonry wall is defined and the capacity of the stone masonry wall is studied varying different physical and mechanical parameters of the wall to explore an analytical model that can represent the capacity of multi-leaf stone masonry. 300 models of multi-leaf stone masonry panels are analysed in ANSYS, and the capacity and displacement parameters are extracted by bilinearization of the pushover curve. As a result, a mathematical model between the capacity of a multi-leaf stone masonry wall and physical and mechanical properties is established.


Sign in / Sign up

Export Citation Format

Share Document