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1

Chitosan/Arabic gum/ZnO bionanocomposite as a novel antibacterial agent

Safaei Mohsen, Salmani Mobarakeh, Azizi Bahram, Shoohanizad Ehsan, Ling Shing Wong, Nikkerdar Nafiseh

Polimery

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2024

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Vol. 69, nr 6

362--370

EN

The synthesis conditions of chitosan/Arabic gum /zinc oxide nanocomposite were optimized using the Taguchi method to obtain antibacterial properties. FT-IR, XRD, FESEM, EDX, TEM, UV/VIS and TGA techniques were used to characterize the nanocomposite. Nanocomposite C3 (1 mg/mL chitosan, 4.5 mg/mL Arabic gum and 8 mg/mL zinc oxide), C7 (3 mg/mL chitosan, 5.1 mg/mL Arabic gum and 8 mg/mL zinc oxide) and C9 (3 mg/mL chitosan, 4.5 mg/mL Arabic gum and 4 mg/mL zinc oxide) had the best antibacterial properties against S. mutans. TGA showed that ZnO improved the thermal stability of the nanocomposite. Such materials can be used as antibacterial agents.

PL

Przy użyciu metody Taguchi zoptymalizowano warunki syntezy nanokompozytu chitozan/guma arabska/tlenek cynku umożliwiające uzyskanie właściwości antybakteryjnych. Do scharakteryzowania nanokompozytu zastosowano techniki FT-IR, XRD, FESEM, EDX, TEM, UV/VIS i TGA. Nanokompozyt C3 (1 mg/mL chitozanu, 4,5 mg/mL gumy arabskiej i 8 mg/mL tlenku cynku), C7 (3 mg/mL chitozanu, 5,1 mg/mL gumy arabskiej i 8 mg/mL tlenku cynku) i C9 (3 mg/mL chitozanu, 4,5 mg/mL gumy arabskiej i 4 mg/mL tlenku cynku) miał najlepsze właściwości antybakteryjne wobec S. mutans. Metodą TGA wykazano, że ZnO poprawia stabilność termiczną nanokompozytu. Tego typu materiały mogą być stosowane jako środki antybakteryjne.

2

Sugar Palm Starch/Chitosan Bionanocomposite Films Incorporated with Anthocyanin and Curcumin – Thermal Properties and Release Kinetics

Rachmina Rachmina, Hasan Muhammad, Hasanah Uswatun, Halim Abdul

Journal of Ecological Engineering

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2024

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Vol. 25, nr 2

300--308

EN

The packaging industry responding to growing consumer demands for product safety, seeks active packaging that allows controlled antioxidant release through incorporating anthocyanin, curcumin, cinnamaldehyde, and other polyphenolic compounds to enhance functional properties of the film antimicrobial interfacial interaction. The research focuses on exploring the impact of adding curcumin and anthocyanin to sugar palm starch/chitosan bionanocomposite films, specifically examining the release kinetics of these bioactive compounds. The biocomposite film with added curcumin exhibits a smoother surface compared to the anthocyanin-based film. Although the thermal stability of the CH/SPS matrix remains unaffected by the addition of anthocyanin and curcumin, the inclusion of these compounds significantly reduces the melting enthalpy of the CH/SPS matrix. Specifically, the addition of curcumin decreases it from 142.96 J/g to 23.43 J/g, and the addition of anthocyanin reduces it to 33.22 J/g. Anthocyanin release from the CH/SPS matrix into water conforms to the Kosmeye-Peppas model (R2 = 0.9808, n = 0.1177), while the release kinetics of curcumin compounds adhere to the Higuchi model (R2 = 0.9968). These findings provide advantageous insights that potentially have implications for a variety of applications, particularly in areas such as sustainable food packaging.

3

Comparative study on the adsorption of lead ions by kaolin loaded chitosan by different modification methods

Zhang Shuqin, Boyue Yuan, Liu Yi, Zhang Kening, Ren Dajun, Zhang Xiaoqing

Environment Protection Engineering

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2024

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Vol. 50, nr 1

27--41

EN

The adsorption effect of two modified kaolin-chitosan composites prepared by different modification methods (cross-linking method (GL-CS) and click reaction method (TGL-CS) on lead ion wastewater was studied. The structure of TGL-CS has a denser pore structure than that of GL-CS, and the distribution of adsorption sites is more uniform. At 25 °C, pH 4, the adsorbent dosage of 0.05 g/dm3, reaction time of 4 h, and initial mass concentration of 150 mg/dm3, TGL-CS had the best effect on Pb2+ wastewater treatment, and the adsorption capacity was 76.159 mg/g. The adsorption studies of kinetic, thermodynamic, and thermodynamic parameters showed that the adsorption on GL-CS and TGL-CS was best described by the Langmuir model. The adsorption mechanism is mainly chemical adsorption. The adsorption process is spontaneous. These results show that the adsorbent prepared by click reaction has obvious advantages, with more adsorption capacity and adsorption sites, faster adsorption rate, and better application potential.

4

Multifunctional sericin-chitosan-Aloe vera composite film for food packaging

Kavi Palepu, Tarangini Korumilli, Kumaravel Varuna, Rao Korukonda Jagajjanani, Wacławek Stanisław, Cheong Jun Young, Padil Vinod V.T.

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 3

297--314

EN

In recent years, the demand for innovative, sustainable, and efficient food packaging solutions has surged in response to growing concerns about environmental impact, food safety, and quality preservation. A sericin-based polymer composite film with multifunctional properties shows promise as an alternative for enhancing food packaging. In this study, sericin-based composite films were prepared by incorporating Aloe vera gel, chitosan, and glycerol into a sericin solution (1.5 % w/v) through facile homogenisation at 70 °C, followed by casting and subsequent drying on a glass platform. The resulting dried film exhibited uniformity, a smooth texture, and successful integration of the composite components. The film demonstrated a moisture content of 21.02 % and a porosity of 3.56 %, with a thickness of (62.1 ± 2.3) μm. It exhibited moderate transparency with reasonable water vapour permeability. Notably, the DPPH scavenging results indicated that the film has a potent antioxidant capacity with an efficacy rate of 99.1 %, supported further by a phenolic content of 11.5 mg GAE per gram of film. Controlled solute migration of components from the composite films was observed, particularly under acidic conditions. Importantly, toxicity evaluation on A549 cells revealed no adverse effects, even at higher concentrations. Due to its consistent film-forming ability, antioxidant potency, controlled migration, and safe nature, the developed sericin polymer-based film could be an effective alternative for food packaging sensitive foods, maintaining oxidative stability, reducing moisture loss, improving quality, and extending shelf life.

5

Effect of asparagus chitosan-rutin coating on losses and waste reduction during storage

Priss Olesia, Hutsol Taras, Glowacki Szymon, Bulhakov Pavlo, Bakhlukova Kseniia, Osokina Nina, Nurek Tomasz, Horetska Iryna, Mykhailova Lyudmyla

Agricultural Engineering

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2024

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Vol. 28, No. 1

99--118

EN

Storage is a crucial component of a sustainable and efficient food supply system. Reduction of postharvest losses and waste is a vital strategy to improve efficiency, ensure product availability, and reduce environ-mental impact. Asparagus (Asparagus officinalis L.) boasts a high nutritional value and complex of phytonutrients. Yet, the storage period for fresh asparagus is quite short, leading to rapid quality deterioration. An effective method to extend storage periods involves postharvest treatments using the natural biopolymer chitosan. The aim of the research was to assess the effectiveness of applying sustainable postharvest treatments based on chitosan and rutin, with a focus on losses and waste reduction during asparagus storage. The impact of the applied storage technology on the visual appeal and sensory attributes of asparagus, along with its effects on respiratory metabolism, weight loss, soluble solids, soluble carbohydrates, chlorophylls, and carotenoids, was systematically assessed. The findings indicate that the post-harvest treatment using chitosan and rutin effectively preserves the visual characteristics of asparaguswhen the storage period is prolonged to a week. A major advantage of this technology is a substantial reduction in waste, achieving the levels of 1.0-1.5%. The proportion of standard products post-storage ranged from 94.4% to 96.0%. The treatment with chitosan and rutin efficiently reduces weight loss by half and suppresses the respiration rate, leading to decreased losses in soluble solids, carbohydrates, chlorophylls, and carotenoids during storage. These outcomes underscore the effectiveness of the applied coating in impeding metabolic processes, resulting in minimized quantitative and qualitative losses in the product quality during a prolonged storage.

PL

Przechowywanie jest istotnym elementem zrównoważonego i skutecznego łańcucha dostaw żywności. Redukcja strat i odpadów po zbiorze stanowi ważną strategię, której celem jest ulepszenie skuteczności, zapewnienie dostępności produktów oraz zmniejszenie wpływu na środowisko. Szparaga (Asparagus officinalis L.) posiada wysokie wartości odżywcze oraz kompleks fitozwiązków. Jednak okres przechowywania świeżej szparagi jest dosyć krótki, za czym idzie gwałtowne pogorszenie jakości. Skuteczna metoda wydłużająca okres przechowywania polega na zastosowaniu po zbiorze zabiegów z użyciem naturalnego chitozanu polimerowego. Niniejsze badanie miało na celu ocenę skuteczności stosowania zrównoważonych zabiegów po zbiorze z zastosowaniem chitozanu i rutyny skupiając się na redukcji strat i odpadów podczas przechowywania szparagi. Systematycznie oceniano wpływ zastosowanej technologii przechowywania na wygląd zewnętrzny i cechy sensoryczne szparagi razem z wpływem na metabolizm oddechowy, straty wagi, rozpuszczalnych cząstek stałych, rozpuszczalnych węglowodanów, chlorofilu i karotenoidów. Wyniki wskazują na to, że zabiegi przeprowadzone po zbiorze z użyciem chitozanu i rutyny skutecznie podtrzymują charakterystykę wizualną szparagi podczas gdy okres przechowywania wydłużony jest o tydzień. Główną korzyścią tej technologii jest widoczna redukcja odpadów na poziomie 1-1-5%. Proporcja standardowych produktów po przechowywaniu wahała się między 94,4 a 96%. Użycie chitozanu i rutyny skutecznie zmniejsza stratę wagi o połowę i hamuje tempo zmniejszając w ten sposób straty rozpuszczalnych części stałych, węglowodanów, chlorofilu i karotenoidów podczas przechowywania. Niniejsze wyniki potwierdzają skuteczność zastosowanej powłoki w blokowaniu procesu metabolicznego, co skutkuje zmniejszonymi stratami ilościowymi i jakościowymi produktu podczas przedłużonego przechowywania.

6

The use of chitosan as an effective carrier of theophylline – an anti-asthmatic drug

Aziz Noor Firas, Hussein-Al-Ali Samer Hasan, Ghareeb Mowafaq Mohammed, Nashwan Nashwan Abdallah

Polimery

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2023

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Vol. 68, nr 3

157--168

EN

In order to solve the problem of frequent drug dosing and increase its effectiveness, theophylline (THP) was deposited on chitosan nanoparticles (CSNPs). THP-CSNPs nanocomposites with the composition of 50, 75, 100 or 150 mg of chitosan (CS) and 25, 50, 75, 100 or 200 mg of tripolyphosphate (TPP) at pH 4.0, 5.0, 6.0 and 6.5 were prepared, and a constant weight of THP of 100 mg. The nanocomposites were characterized by X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared spectroscopy (FTIR). The rate of drug release was also tested. The Minitab 18 program was used to analyze the results. The independent variables were the CS, TPP, and pH, while loading efficiency, zeta potential, and particle size were the dependent variables. The nanocomposites successfully transported and protected the drug, providing its sustained release.

PL

W celu rozwiązania problemu częstego dawkowania leku i zwiększenia jego efektywności teofilinę (THP) osadzono na nanocząstkach chitozanu (CSNPs). Przygotowano nanokompozyty THP-CSNPs o składzie 50, 75, 100 lub 150 mg chitozanu (CS) oraz 25, 50, 75, 100 lub 200 mg trójpolifosforanu (TPP) przy pH 4,0, 5,0, 6,0 i 6,5 oraz stałej masie THP wynoszącej 100 mg. Nanokompozyty charakteryzowano za pomocą dyfrakcji promieniowania rentgenowskiego (PXRD), skaningowej mikroskopii elektronowej z emisją polową (FE-SEM), spektroskopii w podczerwieni z transformacją Fouriera (FTIR). Zbadano również szybkość uwalniania leku. Do analizy wyników wykorzystano program Minitab 18. Niezależnymi zmiennymi były CS, TPP i pH, podczas gdy wydajność ładowania, potencjał zeta i wielkość cząstek były zmiennymi zależnymi. Nanokompozyty z powodzeniem transportowały i zabezpieczały lek, zapewniając jego przedłużone uwalnianie.

7

Preparing Shrimp Shell-Derived Chitosan with Rice Husk-Derived Biochar for Efficient Safranin O Removal from Aqueous Solution

Phuong Do Thi My, Thao Nguyen Thi Thanh, Loc Nguyen Xuan

Journal of Ecological Engineering

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2023

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Vol. 24, nr 1

248--259

EN

In this study, the shrimp shell-derived chitosan was coated onto rice husk-derived biochar to form chitosan/biochar bio-composite beads. The physicochemical properties of biochar (BC) and chitosan/biochar beads (CS@BC) were characterized by BET, SEM-EDX, FTIR, and pHpzc analyses, which were then tested for their capacity to remove Safranin O (SO) from water. In kinetics, the pseudo-second-order model was found to well represent experimental data, indicating the adsorption was mainly a chemical process. The intra-particle diffusion model was not the sole rate-limiting step, because the results did not pass through the origin. In isotherms, both the Langmuir and Freundlich models described well the equilibrium adsorption data. The CS@BC adsorbent showed adsorption capacity at 77.94 mg/g for SO, which is higher than BC adsorbent with 62.25 mg/g (experimental conditions: pH ~ 7.0, dosage = 0.2 g, contact time = 240 min, and temperature = 298 K). The findings revealed that the biochar-loaded chitosan can improve the adsorption capacity of SO. It is predicted that the enhancement in the functional groups (i.e., -NH2 and -OH groups) of CS@BC could contribute to the electrostatic interactions and the complexation between SO and CS@BC, thereby enhancing the Safranin O adsorption from water.

8

Carboxymethyl Cellulose Nanoadsorbent for Remediation of Polluted Water

Khairiah Khairiah, Frida Erna, Sebayang Kerista, Sinuhaji Perdinan, Humaidi Syahrul, Ridwanto, Fudholi Ahmad, Marwoto Putut

Journal of Ecological Engineering

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2023

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Vol. 24, nr 1

336--348

EN

The development of nanoadsorbents for remediation of polluted water in order to obtain clean and healthy water quality has been carried out, namely the incorporation of chitosan, magnetic, and activated carbon materials. The activated carbon used is the result of the synthesis of banana peel waste nanocrystals, while the magnetic is Fe3O4. The method used in this study is an experimental method with coprecipitation through several stages, namely (1) magnetic synthesis of Fe3O4 by thecoprecipitation method, (2) preparation of chitosan solution, (3) synthesis of activated carbon nanocrystals from banana peel waste by the milling process, (4) merger of the three materials, and (5) characterization with SEM/EDX, XRD, FTIR, BET, PSA, TGA, and AAS to test the performance of the material against polluted water. The study found that 210 minutes was the optimal time for the heavy metal ions Fe, Mn, Zn, and Pb to adsorption.The best sample was sample S4 with a ratio of 1:2:2 with adsorption for Zn 92.43%, Fe 95.44%, Mn 89.54%, and Pb 84.38%. For the heavy metal ions: Mn 5624 mg/g, Fe 5849.4 mg/g, Zn 4894.22 mg/g, and Pb 468.2 mg/g, the Langmuir model was used. The adsorption kinetics showed that the reaction order for Pb, Mn, Zn, and Fe ions varied with pseudo-first order and pseudo-second order. Carboxymethyl cellulose nanoadsorbents are effective in remediating the water contaminated with heavy metals, such as Pb, Mn, Zn, and Fe, meeting the environmental health quality standards for water media for sanitation hygiene purposes.

9

Assessment of the Feasibility of Modified Chitosan Beads for the Adsorption of Nitrate from an Aqueous Solution

Jamka Zainab N., Mohammed Wadood T.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

265--278

EN

The objective of the current work was to investigate the effectiveness and mechanism of nitrate removal from an aqueous solution by adsorption using metal (Zr4+)loaded chitosan and Bentonite beads (Cs-Bn-Zr). The study was carried out in a batch system, and the effect of the critical factors on the adsorption performance, such as contact time, initial nitrate anion concentration, and adsorbent dosage, were investigated. In addition, the adsorption equilibrium models of the Langmuir, Freundlich, and Temkin isotherms were evaluated. The modified adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and analysis with an energy-dispersive X-ray analyzer (EDX). The results demonstrated that at 0.2 g of CS-Bn-Zr adsorbent with an initial concentration of 50 mg/l and a contact time of 120 minutes, the maximum removal of nitrate ions was found to be 97.28%. The result demonstrated that the maximum adsorption capacity of nitrite ions on the manufactured bead was 110.46 mg/g. The Freundlich model was shown to be the most effective for the adsorbate of nitrate. The pseudo–first-order model fits the adsorption kinetic data well.

10

Eco-friendly bioplastic material development via sustainable seaweed biocomposite

Tarangini Korumilli, Huthaash Keshav, Kumar V. Nandha, Kumar Selva T., Jayakumar Onattu Damodharan, Wacławek Stanisław, Rao Korukonda Jagajjanani, Padil Vinod V. T.

Ecological Chemistry and Engineering. S

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2023

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Vol. 30, nr 3

333--341

EN

The study focused on the development of an environmentally friendly bioplastic material using sustainable seaweed-based biocomposites. Algal biomass (Gracilaria edulis) was processed and combined with starch, glycerol, glacial acetic acid, and chitosan to create flexible, homogenous biopolymer films. These films exhibited comparable physical properties to commercial plastics and retained their inherent colour post-processing. Spectroscopic analysis revealed intense UV-Vis peak points aligned with seaweed composition. Mechanical testing demonstrated adequate strength and flexibility, similar to starch-based bioplastics, with a tensile strength of 3.383 MPa and lower elongation strength of about 31.90 %. Material migration tests indicated a preference for water, suggesting suitability for low-moisture foods. The bioplastic film displayed notable biodegradability and compostability, showcasing its potential as a sustainable alternative for food packaging. This innovative contribution advances eco-friendly bioplastic material, addressing plastic pollution and promoting biocomposite use.

11

Biomedical applications of nanoparticles of chitosan from marine waste

Ann Mary S., Sandhiya R., Prince S., Venkatraman J. M., Vignesh S., Hikku G. H., Ramachandran S.

Archives of Materials Science and Engineering

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2023

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Vol. 124, nr 2

71--75

EN

Purpose: The review focuses on chitosan nanoparticle synthesis and its biomedical applications. The review briefly explains the biomedical applications of antimicrobials, cancer therapy, gene therapy, and anti-ageing. Notably, the chitosan biological activity can be further increased by coating metal ions such as iron oxide nanoparticles, gold nanoparticles, etc. Design/methodology/approach: Chitosan is the N-acetyl derivative of chitin, which has the unique properties of biodegradability, non-toxicity, polycationic property and biocompatibility— no reports of ZnO sulphated chitosan nanoparticles being produced for antibacterial. We hope for the conduction of antibacterial research of ZnO sulphated chitosan nanoparticles. Findings: The study establishes that metal oxide nano-CH, characterised by an expanded size range beyond conventional parameters, exhibits a broad spectrum of biomedical applications. Its commendable biological attributes, encompassing biocompatibility, non-toxicity, and biodegradability, make it a vehicle for drug delivery in medicine. Research limitations/implications: Nanomedicine is an emerging branch of medicine that applies tools and the basis of nanotechnology for disease prevention, treatment and diagnosis. Moreover, it helps overcome conventional medicine's limitations, including adverse side effects, poor pharmacokinetics and lack of selectivity. Originality/value: Using chitosan extracted from marine waste presents economic advantages. Furthermore, when coated with metal oxide nanoparticles, it enhances biomedical efficacy. Chitosan is an effective drug delivery vehicle, and its theranostic applications are valuable in the biomedical sector.

12

Postharvest treatments influenced the incidence of internal browning, phenol, aba, and GA3 contents of two pineapple clones

Chandra David, Widodo Soesiladi Esti, Kamal Muhammad, Waluyo Sri

Acta Innovations

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2023

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no. 50

74--80

EN

Phenol is an internal browning (IB) enzymatic reaction substrate and endogenous abscisic acid (ABA) used to suppress IB incidence in the Comte de Paris cultivar (Queen type). There is no information on the correlation between pineapple IB to endogenous total phenol content (TPC), ABA, and gibberellic acid 3 (GA3) after postharvest applications of decrowning. Therefore, this research aimed to analyze the relationship of IB incidence to total TPC, ABA, and GA3 after postharvest treatments of decrowning and coating in GP3 and MD2 pineapple clones. The structure was based on a completely randomized design with 3 factors, namely clone (GP3 and MD2), decrowning (crown and crownless), and coating [50 mg L-1 ABA, 1% chitosan, ABA+Chitosan mixture, and control (H2O)]. The results showed that the MD2 had a lower IB incidence and higher TPC than the GP3 stored at 7°C for 37 days. The increased TPC was positively correlated with IB incidence. TPC was also negatively correlated with ABA but positively with endogenous GA3 2 weeks earlier. Coating with 50 mg L-1 ABA and 1% chitosan on MD2 decreased IB incidence. Pineapple crown pruning decreased ABA and increased TPC, GA3, and IB incidence.

13

Novel synthesis of PEGylated chitosan. Part II: Research

Wyrębska Łucja, Masłowska-Lipowicz Iwona, Słubik Anna

Technologia i Jakość Wyrobów

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2022

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R. 67

81--89

EN

This article is a continuation of the article: Synthesis and evaluation of the possibility of using some chitosan derivatives in the leather industry. Part I: Literature Review [1]. Part II describes the synthesis of methoxy poly (ethylene glycol) chitosan (mPEGylated chitosan). Methoxy poly(ethylene glycol) with two different molecular weights was used. The effective grafting of poly(ethylene glycol) (PEG) with chitosan was preceded by the activation of the hydroxyl group in the PEG molecule. Benzenesulfonyl chloride was used to activate the hydroxyl group. The course of the reaction for the preparation of PEG esters and PEG-chitosan was confirmed by chromatography.

PL

Praca jest kontynuacją artykułu: Synteza i ocena możliwości wykorzystania niektórych pochodnych chitozanu w przemyśle skórzanym. Część I: Przegląd literatury [1]. W części II opisano syntezę metoksypoli(glikolu etylenowego) chitozanu (mPEGylowanego chitozanu). Stosowano metoksypoli(glikol etylenowy) o dwóch różnych masach cząsteczkowych. Efektywne szczepienie poli(glikolu etylenowego) (PEG) chitozanem poprzedzone było aktywacją grupy hydroksylowej w cząsteczce PEG. Chlorek benzenosulfonylu zastosowano do aktywacji grupy hydroksylowej. Przebieg reakcji otrzymywania estrów PEG i PEG-chitozanu potwierdzono chromatograficznie.

14

Fizyczne hydrożele na bazie pochodnych chitozanu

Michalik Regina, Kozioł Krzysztof, Wandzik Ilona

Przemysł Chemiczny

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2022

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T. 101, nr 10

822-826

PL

Przedstawiono krótką charakterystykę dwóch pochodnych chitozanu: kationowego chlorku 2-hydroksypropylotrimetyloamoniowego chitozanu oraz anionowego karboksymetylochitozanu. Przeprowadzono ich syntezę oraz zbadano ich koacerwację w środowisku wodnym. Otrzymane substancje miały właściwości hydrożelu.

EN

Cationic 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) and anionic carboxymethyl chitosan (CMC) were synthesized from chitosan according to the modified literature description. FTIR and 1H-NMR were used to demonstrate the structures of chitosan derivs. The degree of HACC quaternization was studied by conductometric titration (DQ = 1.15), and the degree of CMC substitution by 1H-NMR (DS = 1.0, where the ratio of mono-O : mono-N derivatives was 0.7:0.3). Their coacervative properties in the aq. environment were studied. The substances showed hydrogel-like properties and were recommended as water-absorbing additives to mineral fertilizers.

15

Environmentally hazard and toxic exoskeletons of marine crustaceans wastes in synthesizing N-deacetylated chitin

El-Mekawy Rasha E.

Polimery

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2022

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Vol. 67, nr 10

503--508

EN

High molecular weight chitosan was synthesized from shrimp shells. Chemical structure of chitosan was confirmed using FT-IR, XRD, TGA, and SEM analyses. Physicochemical properties of chitosan such as molecular weight (800 000 g/mol), deacetylation degree (80%), ash content (1%) indicating effectiveness of demineralization step in removing minerals, water binding capacity (4220%), and fat binding capacity (537%), were determined. FT-IR spectra exhibited characteristic joint band at 3365 cm-1 due to –OH and –NH2 regarding to the conversion of chitin acetyl group to NH2 of chitosan.

PL

Z muszli krewetek zsyntetyzowano chitozan o wysokiej masie cząsteczkowej. Strukturę chemiczną chitozanu potwierdzono metodami FT-IR, XRD, TGA i SEM. Określono właściwości fizykochemiczne chitozanu takie jak masa cząsteczkowa (800 000 g/mol), stopień deacetylacji (80%), wskazu jącą na skuteczność procesu demineralizacji zawartość popiołów (1%), zdolność wiązania wody (4220%) i zdolność wiązania tłuszczu (537%). Widma FT-IR wykazały charakterystyczne pasmo przy liczbie falowej 3365 cm-1, pochodzące od grup –OH i–NH2, wynikające z przekształcenia grupy acetylowej chityny w NH2 chitozanu.

16

Optimization of flotation efficiency of phosphate minerals in mine tailings using polymeric depressants : experiments and machine learning

Alsafasfeh Ashraf, Alagha Lana, Alzidaneen Ala, Nadendla Venkata Sriram Siddhardh

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 150477

EN

In this study, direct froth flotation experiments were conducted on silicate-rich phosphate tailing samples. The average grade of P2O5 in the flotation feed was 21.6% as determined using a combination of spectroscopic techniques including X-ray powder diffraction (XRD), mineral liberation analysis (MLA), and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Two polymers were selected to promote the depression of silicates and enhance the flotation of phosphates: in-house synthesized hybrid polyacrylamide (Hy-PAM) and chitosan. Flotation efficiency of phosphates was evaluated at different flotation conditions including depressant type, depressant dosage, pH, and the flotation time. Results indicated that the optimum flotation efficiency of phosphate minerals (84.6% recovery at 28.6% grade of P2O5) was obtained when Hy-PAM was utilized at the studied range of pH and flotation time. All datasets produced from the flotation experiments were integrated within the framework of machine learning (ML) using artificial neural networks (ANNs). The ANN platform was trained, validated, and successfully employed to predict the process outcomes in relation to the pulp and reagents characteristics, which in turn were used to determine the optimum values of process variables. Coefficient of determination (R2), mean absolute error (MAE), and root-mean-square error (RMSE) were used as model indicators. Optimization results showed that the peak flotation performance could be achieved at higher dosages of both polymers. However, lower pH and shorter flotation time for Hy-PAM, and higher pH and longer flotation time for chitosan, were predicted to give the optimum process efficiency.

17

Effective separation of specularite and aegirite using chitosan as a novel depressant

Li Mingyang, Zhang Pengpeng, Gao Xiangpeng, Tong Xiong, Xie Xian

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 6

art. no. 151692

EN

As a typical iron-bearing silicate gangue, aegirite often associates with specularite. Due to the iron element contained in aegirite, it has similar surface properties to specularite. Flotation is by far one of the most efficient methods of processing this kind of iron ore. But the traditional depressants unable to take action in the separation of specularite and aegirite. Chitosan was used as a novel depressant to attempt to separate specularite from aegirite through microflotation tests, adsorption tests, contact angle measurements, Zeta potential measurements, and XPS analysis. The flotation results indicate that chitosan show more strong depression effect on specularite than aegirite. Zeta potential measurements, contact angle measurements and adsorption tests demonstrate that chitosan is more inclined to adsorb on the specularite surface than aegirite, which hinders the subsequent adsorption of collector sodium oleate and increases difference in hydrophobicity between the two minerals. The XPS results of specularite validate the adsorption of chitosan on specularite, and illustrate that electrons of chitosan were partially transferred to oxygen and iron atoms in specularite during the adsorption process.

18

Comparison of sorption capacity of biochar-based sorbents for capturing heavy-metallic ions from water media

Bąk Justyna

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 5

art. no. 150265

EN

To develop the sorption efficiency of heavy metals: Cd(II), Co(II), Zn(II) and Pb(II) ions the biochar was modified by chitosan, FeSO4 and NaBH4. The morphology, physical structure and chemical composition of the biochar based sorbents were characterized by the scanning electron miscroscopy method, N2 adsorption and desorption isotherms, X-ray diffractometry as well as the Fourier transform infrared spectroscopywith the attenuated total reflectance analyses. The research of M(II) ions sorption was carried out as a function of pH (2-6), interaction time (0-360 minutes) and temperature (293, 313, 333 K). The maximum sorption was obtained by the ChBC for Zn(II) ions - 19.23 mg/g and for MBC-Pb(II) - 19.11 mg/g. Different kinetic models as well as both isotherm and thermodynamic equations were used the sorption data modelling. For Cd(II), Co(II) and Zn(II) ions the nonlinear regression of the Elovich equation gave the best fit for the experimental data. On the other hand, for Pb(II) ions, the nonlinear forms of pseudo first order and pseudo second order show a better match. The value of the correlation coefficient >0.960 determined from the Freundlich isotherm model is the highest suggesting a good fit to the experimental data. The thermodynamic parameters: ΔG°, ΔH° and ΔS° were listed and indicated that the process is spontaneous and endothermic in nature. The desorption efficiency was determined with the use of nitric, hydrochloric and sulfuric acids and the largest desorption yield for Pb(II)-ChBC equal 99.5 % was gained applying HNO3.

19

A comparative study of biosynthesized marine natural-product nanoparticles as antifouling biocides

Abdelsalam Khaled Mahmoud, Shaltout Nayrah Aly, Ibrahim Hassan Abduallah, Tadros Hermine Ramzy Zaki, Aly-Eldeen Mohamed Abd-Elnaby, Beltagy Ehab Aly

Oceanologia

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2022

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No. 64 (1)

35--49

EN

In this study, biosynthesized nanoparticles using chitosan, Ulva fasciata, and Avicennia marina leaves extracts (A, B, and C, respectively), were evaluated as paint additives to control marine fouling on different substrates. These biocidal nanoparticle compounds were prepared using a green biosynthesis method. Their characterizations were conducted using Fourier-Transform Infrared spectroscopy and Transmission electron microscopy. Each nanoparticle compound was mixed with a prepared paint, resulting in three formulations for each (e.g. 1C, 2C, 3C), containing 20%, 40%, and 60% by weight. Painted PVC, wood, and steel with these nine paints, and the control were immersed in seawater for different periods. After two months of immersion, the least number of fouling species, (one species) was recorded on both the wood and steel panels that were coated with paint (1C). Meanwhile, after four months, the least numbers of fouling (four and six species) were recorded on wood and steel panels that were coated with paint (3C). After around seven months of immersion, the least numbers of fouling species (five and ten) were recorded on wood and steel panels that were coated with paints (1C and 3C), respectively. The steel panel coated with (3C), harbored ∼2% of the total number of barnacles found on the control, after 7 months of immersion. The superior antifouling agent efficiency of extract (C) nanoparticles can be attributed to its constituents of polyphenols, ammonium compounds, and high concentrations of alcohols, besides the presence of both aromatic and aliphatic amide and amide derivatives.

20

Strength, Water Absorption, Thermal and Antimicrobial Properties of a Biopolymer Composite Wound Dressing

Odili Cletus Chiosa, Sekunowo Olatunde Israel, Ilomuanya Margaret Okonawan, Gbenebor Oluwashina Philips, Adeosun Samson Oluropo

Journal of Casting & Materials Engineering

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2022

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Vol. 6, no. 1

22--32

EN

Conventional wound material allows bacterial invasions, trauma and discomfort associated with the changing of the dressing material, and the accumulation of body fluid for wounds with high exudate. However, there is a shift from conventional wound dressing materials to polymeric nanofibers due to their high surface area to volume ratio, high porosity, good pore size distribution, which allows for cell adhesion and proliferation. There is an urgent need to synthesis a biodegradable composite that is resistant to bacterial infection. In this study, an electrospun polylactide (PLA) composite suitable for wound dressing, with enhanced antimicrobial and mechanical properties, was produced. The neat PLA, PLA/CH (10 wt.%), PLA/CH (5 wt.%), PLA/CHS (10 wt.%), PLA/CHS (5 wt.%), PLA/CH (2.5 wt.%) /CHS (2.5 wt.%) and PLA/CH (5 wt.%)/CHS (5 wt.%), were electrospun using 0.14 g/ml solution. Results show that crystallinity (67.6%) of neat PLA declined by 3.8% on the addition of 2.5 wt.% chitin/chitosan with improved hydrophilicity of the composite. The tensile strength of neat PLA (0.3 MPa) increased (0.6 MPa) with 2.5 wt.% chitin/chitosan addition. The slight increase in the glass transition temperature from 75°C for neat PLA to 78°C of the composite fibre, showed improved ductility. The fibres showed little beads, hence suitable for wound dressing. The electrospun mats have good water absorption capacity and strong resistance against Staphylococcus aureus. Good performance was attained at 5 wt.% of chitin, chitosan and hybrid reinforcements. Therefore, a PLA/chitin/chitosan composite is recommended as a wound dressing material.