Wyniki wyszukiwania - BazTech

1

Synergistic Effect of Silk Fibroin/Chlorogenic Acid/Citric Acid on Anti-ultraviolet and Antibacterial Properties of Cotton Fabric

Xiao Minghui, Zhang Wei

Fibres & Textiles in Eastern Europe

|

2024

|

Vol. 32, no. 1

76--82

EN

In order to obtain a durable anti-ultraviolet and antibacterial cotton fabric, silk fibroin, honeysuckle extract (chlorogenic acid) and citric acid were used to prepare a compound environment-friendly finishing agent, and then the cotton fabric was modified in this paper. Micro-morphology and properties were compared between cotton fabrics finished with a composite solution of silk fibroin/chlorogenic acid/citric acid and those finished first with silk fibroin then chlorogenic acid. Results showed that amidation and esterification crosslinking reactions occurred between the compounds and cotton fibers. Cotton fabric treated with the composite solution had higher UPF value (>90 after 30 launderings) and antibacterial rates (>95% for Staphylococcus aureus and Escherichia coli). There existed strong covalent bonds and good synergistic effects among silk fibroin, citric acid and chlorogenic acid, which could endow the cotton fabric with more durable anti-ultraviolet and antibacterial properties.

2

The influence of citric acid on the extraction level of manganese in green and black tea infusions

Kleszcz Krzysztof, Michoń Katarzyna

Science, Technology and Innovation

|

2023

|

Vol. 17, no. 1-2

1--8

EN

Manganese concentration in green and black tea (10 samples of each type) was determined by means of graphite-furnace atomic absorption spectrometry. Both the dry leaves and the infusions were analysed. The concentration of manganese in dry leaves was in the range of 502–1277 mg · kg−1 for black tea and 798–1906 mg · kg−1 for green one. Since lemon juice is commonly added for tea to enrich its taste, citric acid was used to simulate lemon juice influence on manganese concentration in the infusions. The infusions prepared with and without citric acid addition were analysed and the results showed significant influence of citric acid on manganese leaching. The average extraction levels of manganese from black tea equal 16% (for non-acidified infusions) and 34% (for acidified ones) while these values for green tea equal 13% and 38%, respectively. Statistical evaluation of the results showed that the differences between acidified and non-acidified infusions were statistically significant. High manganese content makes the tea an important source of manganese in human diet.

3

Synthesis and characterization of a citric and lipoic acids-derived dendrimer

Salgado-Delgado René, Salgado-Delgado Areli M., Olarte-Paredes Alfredo, García-Fuentes Juan J., López-Lara Teresa, Hernández-Zaragoza Juan B., García-Hernández Edgar, Castaño Víctor M.

Polimery

|

2023

|

Vol. 68, nr 1

25--31

EN

The paper describes the synthesis and characterization of two third generation dendrimers from citric acid and a variant with a dendron terminated with lipoic acid. FTIR and C NMR confirmed the presence of signals characteristic for the dendrimer functional groups OH, C-O, C=O, C-H and C-S. DSC showed that, unlike citric acid, the dendrimer is amorphous. SEM revealed changes in the structure of citric acid particles in each dendrimer generation. In addition, the structure was more homogeneous. Dendrimers are hydrophobic due to ester linkages. Contact angle > 90° confirms their hydrophobic char-acter. Moreover, the dendrimer with a dendron terminated with lipoic acid absorbs Cu+2 and Fe+3metal ions, so it can be used as an adsorbent for heavy metals.

PL

W pracy opisano syntezę i charakterystykę dwóch dendrymerów trzeciej generacji z kwasu cytrynowego oraz wariantu z dendronem zakończonym kwasem liponowym. Metodą FTIR i C NMR potwierdzono sygnały charakterystyczne dla grup funkcyjnych dendrymeru OH, C-O, C=O, C-H i C-S. Metodą DSC wykazano, że w odróżnieniu od kwasu cytrynowego dendrymer jest amorficzny. Mikrofotografie SEM wykazały zmiany w strukturze cząstek kwasu cytrynowego w każdym pokoleniu dendrymeru. Ponadto struktura była bardziej jednorodna. Dzięki wiązaniom estrowym otrzymane dendrymery są hydrofobowe, co potwierdza kąt zwilżania > 90°. Wykazano również, że dendrymer z dendronem zakończonym kwasem liponowym absorbuje jony metali Cu+2 i Fe+3, dzięki czemu może być stosowany jako adsorbent metali ciężkich.

4

Product Concentration, Yield Percentage and Productivity of Citric Acid Formation Using Aspergillus niger Isolated from Palm Dates

Alhadithy Dunya A., Yasin Safaa Rasheed

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 11

1--13

EN

Aspergillus niger isolated from palm dates was examined to produce citric acid. The isolates from zahdi dates (A. niger S11) had the best yield of citric acid with a straightforward and efficient isolation technique without the need for purification of the isolates. The best results of citric acid obtained in the static air, using Czapek dox liquid medium, were 37.116 g/l, 33.742% yield, and 0.0859 g/L•h productivity, and in the 1 vvm air were 47.248 g/L, 42.953% yield, and 0.1094 g/L•h productivity, under temperature 30 °C, mixing speed 150 rpm, pH 4, sugar concentration 11%, and inoculum size 5%. Yield and concentration were 23.139% and 25.453 g/L using Date syrup.

5

Citric Acid as an Eco-Friendly Inhibitor for the EN AW-2024 Aluminum Alloy Corrosion in Acidic Medium

Kamarska Kalina

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 1

307--311

EN

The paper presents the results from a study on the possibility to use citric acid as an ecological inhibitor of corrosion in aluminum alloy EN AW-2024 in 0.5 М solution of H2SO4. The study has been carried out by using electrochemical techniques, such as open circuit potential and chronoamperometry. The results reveal that the presence of citric acid in the studied acid medium reduces the corrosion degree of the EN AW-2024 aluminum alloy. The inhibition efficiency increases together with increasing the concentration of the citric acid. The study shows that the citric acid can be used as an ecological inhibitor to fight corrosion in a solution of H2SO4.

6

Metals Removal from Contaminated Soil Using Electrokinetic Treatment – Effect of Different Permeable Reactive Barrier and Flushing Solution

Budihardjo Mochamad Arief, Ramadan Bimastyaji Surya, Safitri Rahayu Puji, Effendi Agus Jatnika, Hidayat Syarif, Paramitadevi Yudith Vega, Ratnawati Beata

Ecological Engineering & Environmental Technology

|

2023

|

Vol. 24, iss. 2

19--27

EN

Metals pollution is often found in the immediate or neighboring areas of industrial or agricultural activities. This situation may significantly affect the environment, such as water, soil, and air pollution. Electrokinetic (EK) treatment is known to have higher efficiency for metals contaminated soil. However, the use of EK treatment is not widely as expected. This study employs EK treatment with different permeable reactive barriers and flushing solutions to remove Cd and Pb from agricultural soil. Soil pH, temperature, water content, electroosmotic flow, electric current, and metal concentration are calculated as responses to the EK treatment. Results showed that the EK treatments were effectively removed the metals from the contaminated soil. On the fifth day of the treatment, EK, which used activated carbon as PRB and citric acid as the chelating agent, removed a significant amount of Cd from the soil. Besides, the treatment using zeolite as PRB and citric agent as chelate can remove more than 90% of Pb after the sixth day of treatment. These results showed that PRB and chelating agents could effectively remove the metals from the contaminated soils.

7

Biokonwersja glicerolu do kwasu cytrynowego

Książek Ewelina, Janczar-Smuga Małgorzata, Pietkiewicz Jerzy J.

Przemysł Chemiczny

|

2020

|

T. 99, nr 6

939--948

PL

Przedstawiono wyniki badań otrzymywania kwasu cytrynowego z glicerolu bezwodnego oraz odpadowego metodą fermentacji z użyciem szczepów Aspergillus niger. W pierwszej kolejności przeprowadzono badania przesiewowe 19 szczepów A. niger w okresowych hodowlach wgłębnych w kolbach, w inkubatorze z wytrząsaniem. Następnie dla szczepu charakteryzującego się największą wydajnością i efektywnością przeprowadzono okresowe hodowle wgłębne w bioreaktorze. W okresowych hodowlach wgłębnych A. niger PD-66 prowadzonych w podłożach z glicerolem bezwodnym uzyskano wyższe końcowe stężenia kwasu cytrynowego niż w hodowlach prowadzonych w podłożach zawierających glicerol odpadowy. Najwyższe końcowe stężenie kwasu cytrynowego (86,11 g/dm3), największą szybkość objętościową (0,465 g/(dm3•h)) oraz najkorzystniejszy współczynnik efektywności biosyntezy kwasu cytrynowego (40,10%•g/(dm3•h)) otrzymano w hodowlach prowadzonych w bioreaktorze w podłożu hodowlanym z glicerolem bezwodnym. W okresowych hodowlach wgłębnych prowadzonych w podłożu z glicerolem odpadowym zaobserwowano zdecydowanie niższą produktywność i wydajność kwasu cytrynowego.

EN

Anhydrous and crude glycerols were bioconverted to citric acid by using Aspergillus niger mould strains. After screening of 19 strains in submerged batch cultures, in flasks, in a shaking incubator the A. niger PD-66 strain with the highest yield and efficiency, was selected and used in the study. The highest final concn. of citric acid (86.11 g/dm3), the highest volumetric reaction rate (0.465 g/(dm3h)) and the most favourable citric acid biosynthesis efficiency coeff. (40.10%•g/(dm3•h)) were obtained in cultures with anhydrous glycerol. Crude glycerol showed significantly lower productivity and efficiency of citric acid prodn.

8

Effect of fuel type on the combustion reaction behavior, phase structure and morphology of Ni0.5Co0.5Fe2O4 nanoparticles

Sedghi Arman, Salehkooh Elham Akbari, Chadorbafzade Monireh

Materials Science Poland

|

2020

|

Vol. 38, No. 2

341--349

EN

Nickel-cobalt ferrite spinels are ferrimagnetic ceramic materials that possess a great potential for application in high-density magnetic media, recording, color imaging, ferrofluids, and high-frequency devices. A change of their structure from micro- to nano- improves their properties drastically, therefore many methods have been investigated to fabricate nanopowder of these spinels. Gel combustion method is one of them. In this research, Ni0.5Co0.5Fe2O4nanoparticles were fabricated via gel combustion method using metallic nitrates as an oxidant and citric acid, glycine and urea as fuels and the effects of fuel type on the reaction behavior, structure and morphology of Ni0.5Co0.5Fe2O4nanoparticles were investigated. The reaction behavior was studied by thermal analysis method (TGA-DTA), crystallite size of powders was characterized by X-ray diffraction (XRD) and their morphology was studied by FE-SEM. The results revealed that the reaction was initiated in urea, glycine and citric at 219 °C, 197 °C, 212 °C, respectively. Samples fabricated from glycine and citric acid had a pure spinel structure but the others fabricated with urea fuel had iron oxide impurity. The crystallite size of nickel cobalt ferrite nanoparticles was in the range of 58 nm to 64 nm and the nanoparticles were agglomerated.

9

Subcooled flow boiling of a citric acid aqueous mixture

Abdolhossein Zadeh Mohammad Amin, Nakhjavani Shima

Archives of Thermodynamics

|

2020

|

Vol. 41, no 1

193--217

EN

In the present research, an experimental investigation was conducted to assess the heat transfer coefficient of aqueous citric acid mixtures. The experimental facility provides conditions to assess the influence of various operating conditions such as the heat flux (0–190 kW/m2), mass flux (353–1059 kg/m2s) and the concentration of citric acid in water (10%–50% by volume) with a view to measure the subcooled flow boiling heat transfer coefficient of the mixture. The results showed that two main heat transfer mechanisms can be identified including the forced convective and nucleate boiling heat transfer. The onset point of nucleate boiling was also identified, which separates the forced convective heat transfer domain from the nucleate boiling region. The heat transfer coefficient was found to be higher in the nucleate boiling regime due to the presence of bubbles and their interaction. Also, the influence of heat flux on the heat transfer coefficient was more pronounced in the nucleate boiling heat transfer domain, which was also attributed to the increase in bubble size and rate of bubble formation. The obtained results were also compared with those theoretically obtained using the Chen type model and with some experimental data reported in the literature. Results were within a fair agreement of 22% against the Chen model and within 15% against the experimental data.

10

Effect and mechanism of citric acid on flotation separation of siderite and hematite

Han Huili, Yin Wanzhong, Yao Jin, Li Dong

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 1

311--323

EN

Heterocoagulation can occur between fine siderite and hematite particles, which would result in the low efficiency of their separation during the flotation process. To date, there have been no mature methods to increase their separation efficiency. In this paper, citric acid was used as a regulator to enhance the slurry dispersion efficiency. Micro-flotation, scanning electron microscopy (SEM) analysis, settling tests, particle size measurements, zeta potential measurements and E-DLVO theoretical calculations were conducted in the investigations. A maximum recovery difference (53.98%) between siderite and hematite in their mixtures flotation was obtained. Settling tests confirmed that citric acid contributed to improving the dispersion degree of the slurry. SEM analysis indicated that citric acid could clean the surface of particles and weaken the coagulation between siderite and hematite, which were in line with the results of particle size measurements. The zeta potential measurements and Extended-Derjaguin-Landau-Verwey-Overbeek (E-DLVO) theoretical calculations indicated that the citric acid could adsorb on the siderite and hematite surfaces and decreased the surface charge, resulting in a visible increase of the repulsion energy between siderite and hematite particles. Therefore, citric acid can be applied to remove the easily-ground carbonate minerals first to improve the flotation performance of hematite in the separation process of carbonate-containing iron ores.

11

Leaching of lead and copper from flash smelting slag by citric acid

Gargul K., Boryczko B., Bukowska A., Jarosz P., Malecki S.

Archives of Civil and Mechanical Engineering

|

2019

|

Vol. 19, no. 3

648--656

EN

As a direct-to-blister copper flash smelting slag contains important levels of copper (14%) and lead (2–4%) it is subjected to a process of high temperature reduction. To recover copper as well as lead the slag is subjected then to a process of decopperization by reducing the oxide metal compounds in an electric furnace. This study presents an alternative to the above process by recovering Pb and Cu from the slag by a hydrometallurgical route using citric acid solutions. The objective of this study was to determine process parameters at which the effectiveness of the lead leaching process is greatest with the minimum transfer of copper to the solution. This paper presents the results of laboratory tests on flash smelting slag leaching with citric acid solutions. Process parameters (time, temperature, citric acid concentration, l/s ratio) at which the Pb concentration decreases from the initial value (3.05%) to the value of 0.41–0.6% in the post-leaching sediment were determined. Analogous values for copper were 12.44% (before leaching) and 11.5–11.8% (after). The lead and copper content was determined by atomic absorption spectrometry (AAS). The hydrometallurgical method could successfully replace the existing treatment of slag in an electric furnace and converter.

12

Otrzymywanie polimerowych kompozycji hydrożelowych modyfikowanych kwasem cytrynowym oraz badanie ich wybranych właściwości

Okulska-Bożek M., Płachta B., Jabłońska E., Szczerba J., Pyrka S.

Przetwórstwo Tworzyw

|

2018

|

T. 24, Nr 4 (184)

17--25

PL

Otrzymano szereg biomateriałów hydrożelowych, zawierających w swej strukturze kwas cytrynowy (CA), metodą dwuetapową. W pierwszym etapie przeprowadzano chemiczną modyfikację poli(alkoholu winylowego) (PVA) przy użyciu CA w obecności kwasu p-toluenosulfonowego jako katalizatora. Celem modyfikacji było wprowadzenie do łańcuchów hydrofilowego polimeru sieciujących wiązań i mostków estrowych. W etapie drugim otrzymywano materiały hydrożelowe, bazując m.in. na zmodyfikowanym PVA. Wytwarzano materiały, zawierające przenikające się wzajemnie sieci polimerowe, metodą polimeryzacji rodnikowej kwasu akrylowego i/lub metakrylanu metylu, inicjowanej przy użyciu 2,2'-azobis(izobutyronitrylu) (AIBN), prowadzonej w roztworze wodnym zmodyfikowanego PVA. Zbadano rozpuszczalność sporządzonych materiałów hydrożelowych w wybranych rozpuszczalnikach oraz oceniono ich zdolność do pęcznienia (sorpcji wody) w procesie inkubacji próbek w wodzie destylowanej oraz roztworach NaCI, HCl i mocznika, symulujących płyny fizjologiczne ludzkiego organizmu. Obserwowano szybkość desorpcji wody podczas suszenia próbek w temp. 37°C. Na podstawie uzyskanych wyników oceniono, że materiały tego typu mogłyby znaleźć zastosowanie jako hydrożel owe powłoki w technologii leków lub superabsorbenty w wyrobach higienicznych.

EN

The series of hydrogel materials containing ciric acid (CA) in their structure were prepared by the two-step route. In the first step the chemical modification of poly(vinyl alcohol) was conducted by using appropriate amount of CA in the presence of p-toluenesulphonic acid as the catalyst. The introduction of the crosslinking ester fragments to the hydrophilic polymer chains was the aim of this modification. In the second step hydrogels on the base of modified PVA were obtained. Materials with interpenetrating polymer networks were prepared during radical polymerization of acrylic acid and/or methyl metacrylate initiated by 2,2 '-azobis(isobutyronitrile) (AIBN), conducted in water solution of modified poly(vinyl alcohol). The solubility of prepared hydrogel materials for selected solvents was tested. The swelling ratio ability to sorption of water under soaking the samples of hydrogels in distilled water and NaCl, HCl and urea solutions, simulating physiological liquids of human organism, was examined. The rate of water desorption during the process of hydrogel samples drying at the temperature of 37°C was observed. The obtained results showed that such materials could be used as hydrogel layers in the technology of drugs or as superabsorbents in hygienic products.

13

Zastosowanie rotatabilnego planu kompozycyjnego w optymalizacji składu podłoża hodowlanego do biosyntezy kwasu cytrynowego z glicerolu

Dymarska E., Janczar-Smuga M.

Przemysł Chemiczny

|

2018

|

T. 97, nr 8

1276--1282

PL

Wykorzystano centralny rotatabilny plan czynnikowy II stopnia do ustalenia optymalnego składu podłoża hodowlanego do biosyntezy kwasu cytrynowego z użyciem glicerolu bezwodnego jako źródła węgla oraz identyfikowano model matematyczny opisujący wpływ stężenia glicerolu (X1) oraz stężenia makroelementów NH4NO3 (X2), KH2PO4 (X3), MgSO4·7H2O (X4) w podłożu hodowlanym na biosyntezę kwasu cytrynowego. Określono wpływ zmiennych niezależnych na końcowe stężenie produktu (Y1) oraz na współczynnik efektywności biosyntezy kwasu cytrynowego (Y2). W celu wyznaczenia wartości optymalnych zmiennych wejściowych, ze względu na dwa wybrane kryteria końcowe, wykorzystano metodę funkcji użyteczności. Największą wartość użyteczności wynoszącą 0,90 uzyskano dla stężeń glicerolu 150,0 g/dm3, NH4NO3 2,0 g/dm3, KH2PO4 0,2 g/dm3 oraz MgSO4·7H2O 0,2 g/dm3. Dla tak wyznaczonego składu podłoża hodowlanego przeprowadzono eksperyment weryfikacyjny, w wyniku którego uzyskano wartości wybranych kryteriów optymalizacji Y1 = 59,01 g/dm3 i Y2 = 7,00%·g/(dm3·h).

EN

Anhyd. glycerol was bioconverted to citric acid by using Aspergillus niger PD-66 on NH4NO3, KH2PO4, and MgSO4 – contg. substrates at 30°C and 200 rpm for 15 days. The results were evaluated statistically to det. the optimal final concns. of citric acid and biosynthesis efficiency coeff. from the resp. regression equations. A good agreement between the exptl. detd. and calcd. values was achieved.

14

PUR-PIR foam produced based on poly(hydroxybutyl citrate) foamed founded with different factories

Liszkowska J., Czupryński B., Paciorek-Sadowska J., Borowicz M.

Polish Journal of Chemical Technology

|

2018

|

Vol. 20, nr 1

87--95

EN

A poly(hydroxybutyl citrate) p(HBC) was obtained. The product compound produced in the solution during esterification, was added to rigid polyurethane-polyisocyanurate foams (PUR-PIR). The amount of petrochemical polyol in the foams was decreased in favor of the p(HBC) from 0.1 to 0.5 equivalent. The foams were foamed in two ways: with distilled water (W foams) and with Solkane 365/227 (S foams). The examination results of both foam series were compared. They showed that the foams foamed with water have higher softening temperature than the foams foamed with solkane. The retention values for both foam series are around 91–95%, and water absorption in the range of 0.7–3.2%. The anisotropy coefficient did not exceed 1.08 (the lowest value being 1.01).

15

The Influence of Electrical Current Density and Type of the External Source of Carbon on Nitrogen and Phosphorus Efficiency Removal in the Sequencing Batch Biofilm Reactor

Kłodowska I., Rodziewicz J., Janczukowicz W.

Journal of Ecological Engineering

|

2018

|

Vol. 19, nr 5

172--179

EN

This work presents the results of a study on the effect of electrical current density (53, 105, 158 and 210 mA/m2), type of the external source of carbon (citric acid, potassium bicarbonate), and C/NNO3 ratio (0.5, 1.0 and 1.5) on the effectiveness of nitrogen and phosphorus removal from synthetic wastewater with physicochemical parameters typical of municipal sewage subjected to bio-treatment in the highly efficient system for organic compounds removal ensuring efficient course of the nitrification process. The denitrification efficiency was found to depend on the type and dose of carbon and on the electrical current density. Higher values of this parameter were determined in the reactor with citric acid than in one with potassium bicarbonate used as carbon sources. Total phosphorus was removed in the processes of electrocoagulation and biomass growth. Higher efficiency of dephosphatation was achieved in the reactor with electrical current passage than in the reactor without it. The type of carbon source had little effect on the dephosphatation efficiency. The use of electrical current density of 210 mA/m2 and citric acid as a carbon source with C/N=1.5 allowed achieving 87.61(±1.6)% efficiency of denitrification and 97.69(±2.1)% efficiency of dephosphatation.

16

Effect of Electrical Current and the External Source of Carbon on the Characteristics of Sludge from the Sequencing Batch Biofilm Reactors

Kłodowska I., Rodziewicz J., Janczukowicz W.

Journal of Ecological Engineering

|

2018

|

Vol. 19, nr 4

143--152

EN

This work presents the results of an experiment on the effect of electrical current density (53, 105, 158 and 210 mA/m2), the type of an external source of carbon (citric acid, potassium bicarbonate) and C/NNO3 ratio (0.5, 1.0 and 1.5) on the quantity and quality of formed sludge. The experiment was conducted in sequencing batch biofilm reactors (SBBRs), under anaerobic conditions, with and without the passage of electrical current, under controlled pH of 7.5–8.0. The study demonstrated that in the reactors with electrical current passage and external source of carbon, the volume of sludge increased along with the current density increase from 53 to 158 mA/m2. At its highest density (210 mA/m2), the concentration of sludge was insignificantly lower. For all densities of electrical current and C/NNO3 values, the concentrations of sludge formed in the reactors with potassium bicarbonate (1.00 to 1.26 g d. m./L) were lower than in the reactors with citric acid (1.26 to 1.30 g d. m./L). The concentration of organic matter was higher in the sludge from the reactors with electrical current passage and potassium bicarbonate, compared to the sludge from the reactors with citric acid. In the reactors with electrical current passage and external source of carbon, the total nitrogen content in the sludge decreased along with the C/NNO3 ratio increase for current densities of 53 and 105 mA/m2. For a higher electrical current density, the nitrogen content in the sludge was similar. Irrespectively of the current density, the nitrogen content in the sludge from the reactors with citric acid was higher than in the sludge from the reactors with potassium bicarbonate. For higher current densities (158 and 210 mA/m2) the increase in the C/NNO3 value caused an increase in the P content in the sludge. The electrical current density increase contributed to increasing the content of phosphorus in the sludge. The phosphorus content in the sludge from the reactors with citric acid was lower than in the sludge from the reactors with potassium bicarbonate. The CST values prove that the sludge formed during the wastewater treatment in electrobiological SBBR was characterized by very high dewaterability. The capillary suction time decreased along with increasing the electrical current density but was not significantly affected by the type of carbon source.

17

Application of Environment-Friendly Processes Aimed at Bonding β-Cyclodextrine onto Cellulosic Materials

Grgac S. F., Malinar R.

Fibres & Textiles in Eastern Europe

|

2018

|

Vol. 26, no. 5 (131)

63--69

EN

The impact of the pre-treatment of cellulose material in NaOH solution and of microwave radiation on the mechanism of crosslinking β-cyclodextrin with cellulose was investigated in this paper. Citric acid and Na-hypophosphite as catalysts were applied for better crosslinking. Inclusion compounds with tea tree essential oil and cyclodextrines grafted onto cotton fabric were made in order to verify that cavities were available for inclusion compounds. The permanence of β-CD on the cellulose fabrics treated was tested by ISO 6330:2012. The properties and structure of the materials treated were characterised by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The breaking force and mechanical damage of the materials were determined according to EN ISO 13934-1:1999. The results indicated better bonding between cellulose and β-cyclodextrin where microwave treatment was applied, the phenomenon of which is of great importance for long lasting wash durability. In order to quantify the odour releasing behaviour of β-CD treated cellulose fabrics, olfactometric determination of the intensity of odour was undertaken.

PL

Badano wpływ wstępnej obróbki materiału celulozowego w roztworze NaOH i promieniowania mikrofalowego na mechanizm sieciowania β-cyklodekstryny z celulozą. Dla lepszego usieciowania zastosowano kwas cytrynowy i Na-podfosforyn jako katalizator. Zastosowano także olej eteryczny z drzewa herbacianego i cyklodekstryny szczepione na tkaninie bawełnianej. Trwałość β-CD na obrabianych tkaninach celulozowych została przetestowana zgodnie z normą ISO 6330: 2012. Właściwości i strukturę obrabianych materiałów scharakteryzowano za pomocą spektroskopii w podczerwieni z transformatą Fouriera (FTIR) i skaningowej mikroskopii elektronowej (SEM). Siła zrywająca i mechaniczne uszkodzenia materiałów zostały określone zgodnie z normą EN ISO 13934-1: 1999. Wyniki wskazują na lepsze wiązanie pomiędzy celulozą i β-cyklodekstryną, w której zastosowano obróbkę mikrofalową. Zjawisko to ma ogromne znaczenie dla długotrwałej trwałości na pranie. W celu ilościowego określenia uwalniania nieprzyjemnych zapachów tkanin celulozowych poddanych obróbce β-CD, przeprowadzone zostało olfaktometryczne oznaczanie intensywności zapachu.

18

Phytoextraction of Cr by maize (Zea mays L.) : the role of plant growth promoting endophyte and citric acid under polluted soil

Ali J., Mahmood T., Hayat K., Afridi M. S., Ali F., Chaudhary H. J.

Archives of Environmental Protection

|

2018

|

Vol. 44, no. 2

73--82

EN

High chromium (Cr) toxicity has turned into a serious environmental concern. Cr contaminated agronomic soils negatively affect the growth and yield of crops. Current research was conducted to enhance the phytoextraction potential of maize by using Burkholderia vietnamiensis and citric acid (CA). Plants were subjected to three concentrations of Cr (0.86, 350, and 500 ppm). A pot experiment was conducted under greenhouse conditions with completely randomized design (CRD). After 72 days of experiment, plants were harvested to analyze the morphological and biochemical attributes of soil, bacteria and plant. Results revealed that plant fresh, dry biomass, root, shoot length and chlorophyll contents significantly increased by 56%, 50%, 58%, 78% and 60%, respectively, at 500 ppm Cr concentration in combine treatment of B. vietnamiensis and CA. Maize plants treated with both B. vietnamiensis and CA significantly increased the bioaccumulation (BA) of Cr up to 50% and translocation factor (TF) by 31%. Furthermore, superoxide dismutase (SOD), proline and peroxidase dismutase (POD) activities in leaves were markedly increased by 30%, 42% and 15%, respectively, when treated with CA. Current study reveals that exogenous co-application of B. vietnamiensis + CA enhance plant growth by alleviating heavy metal stress and accelerate the phytoextraction of Cr. Taking into account the heavy metal tolerance and accumulation capacity, Zea mays is suitable for phytoremediation of contaminated soils in combination with B. vietnamiensis and CA.

19

Study on the effect of modification with furfuryl alcohol on selected properties of poplar wood (Populus nigra L.)

Drywień K., Radomski A.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

|

2018

|

No. 104

339--344

EN

In these study black poplar wood (Populus nigra L.) was modified by vacuum impregnation with furfuryl alcohol with the addition of citric acid. Then it was subjected to temperature conditions in order to cure this alcohol inside the lumen. WPG, water absorbability and color change was tested on the samples that were modified with method. The aim of the research was to investigate the influence of such modification on selected properties of black poplar wood. Samples after modification was compared with the samples that were not modified and with the samples that have only been subjected to high temperature conditions with no addition of furfuryl alcohol. Furfurylated samples showed improved water reisistance, measured as absorbability. The change of color is very clear, though differences between two highest concentrations of modifier were neglibigle.

20

Synteza i analiza struktury kopolimerów kwasu mlekowego i kwasu cytrynowego

Florjańczyk Z., Chudzik A., Frydrych A., Rucińska K.

Polimery

|

2017

|

T. 62, nr 5

335--343

PL

Badano procesy kondensacji kwasów cytrynowego i mlekowego w stopie oraz metodą sprzęgania w obecności dicykloheksylokarbodiimidu. Otrzymane produkty analizowano za pomocą technik magnetycznego rezonansu jądrowego (1H NMR), spektroskopii mas (MALDI ToF) oraz chromatografii żelowej (GPC). Wykazano, że kondensacja w stopie prowadzi na ogół do skomplikowanej mieszaniny kopolimerów oraz homopolimerów kwasu mlekowego. Połączenie obu metod pozwala natomiast otrzymać, z wysoką wydajnością, kopolimery o budowie rozgałęzionej o wagowo średnich masach molowych 9–27 kg/mol i wartościach Mw/Mn = 1,3–2,0. Metodą sprzęgania uzyskano także amfifilowe kopolimery zawierające hydrofobowy rdzeń złożony z merów kwasów cytrynowego i mlekowego oraz hydrofilowe segmenty polioksyetylenowe. Produkty te tworzą w wodzie stabilne koloidalne dyspersje o średnicach cząstek rzędu 50–500 nm.

EN

The processes of condensation of citric and lactic acids carried out in melt or by coupling in the presence of dicyclohexylcarbodiimide have been investigated. The obtained products were analyzed using 1H NMR, MALDI ToF and GPC techniques. It has been shown that the condensation in melt leads generally to acomplicated mixture of lactic acid copolymers and homopolymers. However, the combining of both methods allows to obtain in high yield the copolymers with branched structure, weight-average molar masses in the range 9–27 kg/mol and Mw/Mn values between 1.3 and 2.0. By using the coupling method, amphiphilic copolymers containing ahydrophobic core composed of citric and lactic acid monomeric units and hydrophilic polyoxyethylene segments were obtained as well. These products form stable colloidal aqueous dispersions with particle diameters ranging from 50 to 500 nm.