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Badanie nad przygotowaniem i analiza zmodyfikowanego proszku bambusowego

Ying Fang, Zhu Wen

Przemysł Chemiczny

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2024

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T. 103, nr 3

429--432

PL

Powierzchnię proszku bambusowego zmodyfikowano chemicznie alkalicznym roztworem Na₂CO₃ w celu poprawy właściwości materiału. Krystaliczność i współczynnik aktywacji zostały użyte jako wskaźniki. W optymalnych warunkach procesu (Na₂CO₃ stężenie 15%, temp. 90ºC i czas reakcji 30 min) krystaliczność proszku osiągnęła 38,5%, a współczynnik aktywacji wyniósł 78,5%.

EN

The surface of bamboo powder was chem. modified with alkal. Na₂CO₃ soln. to improve the material properties. The crystallinity and activation index were used as indicators. Under optimum conditions of the process (Na₂CO₃ concn. 15%, temp. 90ºC and reaction time 30 min), the crystallinity of the powder reached 38.5% and the activation index was 78.5%.

2

Effect of Surface Chemical Treatment of Himalayan Nettle and Investigation of Surface, Physical and Mechanical Characteristics in Treated Nettle Fibre

Deepa R., Kumaresan K., Saravanan K.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

571--578

EN

The main focus of this work was the effect of chemical alkaline treatment on Himalayan nettle fibre extraction and the characterization analysis of surface-modified nettle fibre. Nettle fibre is an eco-friendly material naturally grown in the Himalayan hills of India, and it is replacing man-made fibres. The fibres are primarily bound to each other and, in turn, to the core of the plant with pectin, lignin, and gums, which begin to break down through fungal, bacterial, enzymes and chemical treatment action. The stem from the nettle plant is fibrous and has a high-quality fibre to develop nettle yarn, which is utilized to make clothes and handicrafts, mostly aimed at generating livelihood opportunities for the rural tribe’s people. This method of extraction is an effective chemical treatment for enhancing interfacial adhesion between nettle fibres and the epoxy, which is one of the significant challenges to their usage in textiles. In this paper, nettle fibres treated with chemicals such as 1% sodium hydroxide (NaOH), 0.5% sodium sulphite (Na2SO3), 0.05% ethylenediaminetetraacetic acid (EDTA), and 2% acetic acid (CH3COOH). The impact of bacterial and chemical treatments on nettle fibre and untreated nettle fibre was characterized by Fourier transform infrared spectroscopy (FTIR) analysis, which is used to study the functional elements, Scanning electron microscopy (SEM) images revealed that there is a fibre breaking mechanism and cross-section of yarn twist formation, physical and mechanical characteristics were then determined for fibre tensile strength, fibre length, Young’s modulus, elongation break, fineness, and moisture content.

3

Effect of alkaline treatment on mechanical properties of palmyra and S-glass fiber reinforced epoxy nanocomposites

Sravya Navuluri Padma, Sivaganesan S., Venkatesh R., Manikandan R.

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e116, 2023

EN

Although epoxy resins have many advantages, their use needs to be expanded by improving their mechanical properties, including a wide variety of material quality, easy processing, negligible shrinkage due to curing, and good adhesiveness to many forms of fiber materials. The research focuses cost-effective utilization of palmyra fiber treated with 5% alkali solution and different volume percentages of S-glass fiberglass incorporated by epoxy resin developed by hand layup technique. The final epoxy hybrid composite consists of different weight ratios of palmyra/S-glass fiberglass as 25:75, 50:50, and 75:25. Influences of palmyra (treated) fiber dispersion quality on density, voids, mechanical and moisture absorption performance of the epoxy hybrid composite is studied by ASTM rule. The elevated output characteristics performance is compared with untreated fiber composite. Based on the rule of mixture, composite density is varied and Archimedes’ principle measures voids. The alkali treated composite samples showed good tensile stress, flexural and impact strength. While compared to untreated fiber composite, the tensile, flexural, and compressive strength of TPF/GF(25:75) composite was improved by 19.58%, 29%, and 14.3%, respectively. The reduced water absorption behaviour was observed on the treated composites. The effect of fiber dispersion on the mechanical failure of hybrid composite is studied by SEM analysis.

4

Photocatalytic TiO2 Nanostructures Developed on the Grade 2 Ti Material

Tarcea Claudia I., Pantilimon Cristian Mircea, Coman George, Turcanu Andreea A., Predescu Andra Mihaela, Matei Ecaterina, Berbecaru Andrei-Constantin, Predescu Cristian

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1079--1084

EN

The research focused on TiO2 nanostructures environmental applications due to the special characteristics that displayed degradation of the organic compounds into environmentally friendly products through exposure to UV light. The protocol behind obtaining the nanostructures involved the use of a Ti material exposed to alkaline treatment and advanced oxidation using NaOH solution and acetone. These studied nanostructures were analyzed extensively by using methods such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) for characterizing the elements, compounds and morphological properties of the material. These differences in morphology is attributed to different NaOH solution concentrations. The Ti sheets were immersed into NaOH and acetone mixed solutions for 72 hours. The best results were recorded by using 30% NaOH solution. After obtaining the 3D structures, which improve specific surface and contact area with the environment, the samples were tested under UV light in order to degrade methylene blue in order to determine their photocatalytic performance.

5

Obróbka wstępna biomasy konopi w procesie otrzymywania bioetanolu

Gieparda Weronika, Batog Jolanta, Wawro Aleksandra

Przemysł Chemiczny

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2019

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T. 98, nr 12

1958--1961

PL

Biomasę konopi (Białobrzeskie i Tygra) rozdrobniono, a następnie wykonano test enzymatyczny dla poszczególnych frakcji, oznaczając zawartość cukrów redukujących. Odmiana Tygra wykazała większą zawartość cukrów w stosunku do odmiany Białobrzeskie. Optymalizacji warunków chemicznej obróbki biomasy konopi dokonano za pomocą roztworu NaOH o stężeniu 1,5, 2 i 3%. Stwierdzono, że odmiana Tygra była bardziej podatna na działanie alkalicznej obróbki biomasy niż odmiana Białobrzeskie, szczególnie przy zastosowaniu 2-proc. roztworu NaOH. Wykonano oznaczenie składu chemicznego biomasy konopi przed i po obróbce. Obróbka alkaliczna spowodowała częściową degradację hemiceluloz i pozorny wzrost zawartości celulozy. Spadek zawartości hemiceluloz został potwierdzony przez widma FT-IR. Ponadto na obrazach SEM zaobserwowano oczyszczenie powierzchni biomasy.

EN

Hemp biomass (Białobrzeskie and Tygra varieties) was grounded with a chopper or knife mill into fractions with a particle size of 2, 4, 10 and 10–20 mm. An enzyme test was performed for each fraction to det. the content of reducing sugars. The variety of Tygra showed higher sugar content than the Białobrzeskie one. Optimization of chem. treatment conditions of hemp biomass was performed using 1.5, 2 and 3% NaOH soln. The Tygra variety was more susceptible to alk. treatment than the Białobrzeskie variety, especially when 2% NaOH soln. was used. The chem. compn. of hemp biomass before and after chem. treatment was detd. The alk. treatment resulted in partial degrdn. of hemicelluloses and an apparent increase in cellulose content what was confirmed by IR measurements.

6

Progress in the Production of Biogas from Maize Silage Following Alkaline and Thermal Pre-Treatment

Nowicka A., Zieliński M., Dębowski M., Dudek M.

Rocznik Ochrona Środowiska

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2018

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Tom 20, cz. 1

741--762

EN

This study analysed the effects of microwave radiation and sodium hydroxide on the destruction of lignocellulosic plant biomass (maize silage) and determined the susceptibility of a pre-treated substrate on anaerobic decomposition in the methane fermentation process. The effects of microwave heating-based disintegration were compared to conventional heating. The highest effectiveness of biogas production was obtained during the fermentation of a substrate conditioned using microwave radiation with the addition of NaOH in an amount of 0.2 g/gd.m., and the obtained result was 11.3% higher than a sample heated conventionally and was 29.4% higher than a sample subjected to no chemical treatment.

PL

Celem opisanych badań była analiza oddziaływania promieniowania mikrofalowego oraz wodorotlenku sodu na destrukcję lignocelulozowej biomasy roślinnej (kiszonka kukurydzy) oraz określenie podatności wstępnie przygotowanego substratu na beztlenowy rozkład w procesie fermentacji metanowej. W toku prac porównano efekty dezintegracji w oparciu o ogrzewanie mikrofalowe z wynikami uzyskanymi podczas ogrzewania konwencjonalnego. Najwyższą efektywność produkcji biogazu uzyskano podczas fermentacji substratu kondycjonowanego przy pomocy promieniowania mikrofalowego z dodatkiem NaOH w ilości 0,2 g/gs.m., otrzymany wynik był o 11,3% większy od próby ogrzewanej konwencjonalnie i o 29,4% większy od próby nie poddanej obróbce chemicznej.

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Novel Extraction Process Of Rare Earth Elements From NdFeB Powders Via Alkaline Treatment

Chung K. W., Kim C.-J., Yoon H.-S.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1301--1305

EN

The alkaline treatment of NdFeB powders in NaOH solution at various equivalent amounts of NaOH at 100°C was performed. The resultant powders were then leached in 0.5M H2SO4 solution at 25°C for 2 minutes. At 5 equivalents of NaOH, neodymium in NdFeB powders was partially transformed to neodymium hydroxide. The transformation of neodymium to neodymium hydroxide actually occurred at 10 equivalents of NaOH and was facilitated by increasing the equivalent of NaOH from 10 to 30. In addition, iron was partially transformed to magnetite during the alkaline treatment, which was also promoted at a higher equivalent of NaOH. The leaching yield of neodymium from alkaline-treated powders was increased with an increasing equivalent of NaOH up to 10; however, it slightly decreased with the equivalent NaOH of over 10. The leaching yield of iron was inversely proportional to that of rare earth elements. NdFeB powders treated at 10 equivalents of NaOH showed a maximum leaching yield of neodymium and dysprosium of 91.6% and 94.6%, respectively, and the lowest leaching yield of iron of 24.2%, resulting in the highest selective leaching efficiency of 69.4%.

8

Dyeing characterisations of alkoxide pre-treated acrylic-polyester fibres blend by the use of a cationic dye

El-Gabry L. K., Bendak A.

Polish Journal of Applied Chemistry

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2006

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Vol. 50, nr 3-4

83-94

EN

Acrylic, Polyester fibres and their blend fabrics have been treated with cthanolic or propanolic sodium hydroxide solutions. The treated fabrics were dyed with a cationic dye. The pretreatments were found to improve the dyeability of both types of fibres. The pretreated acrylic/polyester blend can be simply dyed in one bath with single cationic dycstuff. Kinetic investigations of the dyeing process as well as the fastness properties of the dyed fabrics arc also given. The changes in moisture regain, loss in weight, tensile strength and elongation for pretreatment acrylic and polyester have been also studied.

9

Alkaline Treatment of Dibutyrylchitin Fibres Spun from Polymer Solution in Ethyl Alcohol

Biniaś A., Boryniec S., Biniaś W., Włochowicz A.

Fibres & Textiles in Eastern Europe

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2006

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Vol. 14, no. 3 (57)

12--18

EN

Dibutyrylchitin (DBCH) was obtained from native krill chitin by its esterification with butyric anhydride. In this study, DBCH was the initial material for the fibre formation. DBCH fibres were manufactured from a polymer solution in ethyl alcohol by extrusion. Because a dry-wet formation method was applied, the fibres obtained had a porous core. The microporous DBCH fibres were then treated with aqueous KOH solutions. By applying various parameters of the alkaline treatment, DBCH fibres can be transformed into fibres from the regenerated chitin or even into chitosan fibres. The use of a potassium hydroxide solution as an alkaline medium enables a total reconstruction of the original supermolecular structure of chitin. When transforming DBCH fibres into the regenerated chitin fibres, diluted KOH solutions were applied, whereas treatment at an elevated temperature with saturated KOH solutions obtained chitosan fibres with various values of deacetylation degree. At every stage of the treatment, the structural changes in the fibres were examined using IR spectroscopy (FTIR), wide-angle X-ray diffraction and scanning electron microscopy (SEM).

PL

Dibutyrylochitynę otrzymuje się w wyniku reakcji estryfikacji bezwodnika/masłowego z chityną. Otrzymana w taki sposób dibutyrylochityna (DBCH) stanowi surowiec wyjściowy do formowania z niej włókien. Włókna DBCH formowano z roztworów sporządzonych w bezwodnym alkoholu etylowym. Zastosowano metodę formowania systemem sucho-mokrym, dzięki czemu otrzymano włókna z porowatym rdzeniem. Mikroporowate włókna dibutyrylochitynowe poddano następnie obróbce alkalicznej za pomocą roztworów KOH. Stosując zmienne parametry obróbki alkalicznej można przeprowadzić włókna dibutyrylochitynowe we włókna z chityny regenerowanej lub włókna chitozanowe. W przypadku modyfikacji prowadzącej do uzyskania włókien z chityny regenerowanej, stosuje się rozcieńczone roztwory KOH. Natomiast stosując nasycone roztwory KOH w podwyższonych temperaturach uzyskujemy włókna chitozanowe o różnym stopniu deacetylacji. Na każdym etapie obróbki włókien prowadzono badania zachodzących w nich przemian strukturalnych, przy wykorzystaniu spektroskopii w podczerwieni (FTIR) i szerokokątowej dyfrakcji promieniowania rentgenowskiego (WAXS). Obserwowano również zmiany na powierzchni włókien przy zastosowaniu mikroskopu skaningowego (SEM).

10

Dyeing Polyester and Cotton - Polyester Fabrics by Means of Direct Dyestuffs after Chitosan Treatment

Walawska A., Filipowska B., Rybicki E.

Fibres & Textiles in Eastern Europe

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2003

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Vol. 11, no. 2 (41)

71--74

EN

Research into the process of dyeing polyester and cotton-polyester fabrics using direct dyestuffs was carried out. In order to improve the adhesion of chitosan to the surface of polyester fibres, pre-treatment in NaOH solutions was performed. The colour and rubbing fastness properties of the chitosan-deposited fabrics were assessed. The colour difference between the dyed blank samples and samples dyed after alkaline and/or chitosan treatment was estimated using spectrophotometer evaluation. The data obtained shows that it is possible to dye polyester and cotton-polyester fabrics finished by chitosan with only one direct dyestuff, which normally shows substantivity to cellulose fibres. The dyed samples showed good rubbing and washing colour fastness properties within the range of colour change. The colour strength of the dyed samples increased with the increased deposition of chitosan on the fabric.

PL

Wykonano badania możliwości barwienia tkanin PES i PES-bawełnianych, poddanych obróbce chitozanowej, z zastosowaniem barwników bezpośrednich. W celu zwiększenia adhezji chitozanu do powierzchni włókna PES przeprowadzono wstępną obróbkę tkanin w roztworze NaOH. Określono odporności wybarwień na tarcie i pranie. Za pomocą techniki spektrofotometrycznej dokonano oceny różnicy barwy pomiędzy wyjściowymi próbkami a próbkami barwionymi po obróbce alkalicznej i/lub chitozanowej. Wyniki badań wskazują na to, że istnieje możliwość barwienia tkanin mieszankowych PES-bawełnianych w jednej kąpieli, przy użyciu barwników bezpośrednich, posiadających substantywność do włókien celulozowych. Uzyskane wybarwienia charakteryzują się dobrą odpornością na tarcie suche i pranie oraz średnią odpornością na tarcie mokre. Intensywność uzyskanych wybarwień zwiększa się wraz ze wzrostem ilości naniesionego chitozanu na włókno. Zdolności aplikacyjne chitozanu zależą w istotny sposób od jego masy cząsteczkowej i stopnia deacetylacji.