Sodium Periodate Research Articles

A composite film of oxidized levan crosslinked with gelatin: strong hydrophobic and mechanical properties and effective preservation of fresh Mozzarella cheese.

The fructosan levan was synthesized in vitro using a recombinant levansucrase. The levan was oxidized with sodium periodate to prepare oxidized levan (OLevan) with three oxidation degrees. OLevan, gelatin (Gel), and gallic acid (GA) were used to prepare the composite films by the method of plate pouring. The analytical results of FT-IR and XPS indicated that OLevan and gelatin were covalently crosslinked through a Schiff base reaction. The crosslinked films had better properties compared to the non-crosslinked films, especially the Gel/GA/50%OLevan film. The film had the lowest swelling degree (44.4 %), while that of Gel/GA/Levan film was 352.6 %. Gel/GA/50%OLevan film also had the highest tensile strength (25.48 MPa), while that of Gel/GA film was 9.48 MPa. Also, Gel/GA/50%OLevan film was used as a packaging material of Mozzarella cheese. The film effectively slowed down changes in the texture and color of the cheese. On the first day, the coliform in the control and PE groups had already exceeded the maximum acceptable limit of cheese (2.0 Log CFU/g). However, that of Gel/GA/50%OLevan group reached the limit on the fifth day. The results show that the new film prepared by crosslinking and composite of natural edible materials has good potential as a safe food packaging material.

Study on Flame Retardancy of Cotton Fabric Modified by Sulfonic Groups Chelated with Ba2+

A simple and innovative method was introduced for the production of green and recoverable flame-retardant cotton fabrics, where sulfonated cotton fabric (COT-SC) was synthesized by oxidizing cotton fabric with sodium periodate, followed by a sulfonation step with sodium bisulfite to provide active sites, which further chelated barium ions (Ba2+) to achieve flame retardancy. The morphological and structural characterizations of the fabricated cotton fabrics (COT-SC-Ba) demonstrated that the cleavage of C2-C3 free hydroxy groups within the cellulose macromolecule was chemically modified for grafting a considerable number of sulfonic acid groups, and Ba2+ ions were effectively immobilized on the macromolecule of the cotton fabric through a chelation effect. Results from cone calorimeter tests (CCTs) revealed that COT-SC-Ba became nonflammable, displayed a delayed ignition time, and decreased the values of the heat release rate (HRR), total smoke release (TSR), effective heat of combustion (EHC), and CO/CO2 ratio. TG/DTG analysis demonstrated that COT-SC-Ba possessed greater thermal stability, fewer flammable volatiles, and more of a char layer during burning than that of the original cotton fabric. Its residual mass was increased from 0.02% to 26.9% in air and from 8.05% to 26.76% in N2, respectively. The COT-SC-Ba not only possessed a limiting oxygen index (LOI) of up to 34.4% but could also undergo vertical burning tests evidenced by results such as the non-afterflame, non-afterglow, and a mere 75 mm char length. Those results demonstrated that the combination of SO3− and Ba2+ promoted the formation of a char layer. Moreover, cotton fabric regained its superior flame retardancy after being washed and re-chelated with Ba2+. Additional characteristics of the cotton fabric, such as the rupture strength, white degree, and hygroscopicity, were maintained at an acceptable level. In conclusion, this research can offer a fresh perspective on the design and development of straightforward, efficient, eco-friendly, and recoverable fire-retardant fabrics.

Growth and Lipid Production of Ankistrodesmus Sp. IFRPD 1061 Under Mixotrophic Culture Condition: Effect of Sodium Acetate Concentration and Period Addition of Sodium Acetate in an Open Pond

AbstractMicroalgae with increased amount of biomass and lipid yield are crucial for biodiesel production. Mixotrophic cultivation has prominence for increasing the micro‐algal cell concentration and hence the volumetric productivity owing to independent utilization of both the photo‐assimilation of CO2 and oxidative assimilation of organic carbon sources. In this study, Ankistrodesmus sp. IFRPD 1061 was examined under various concentrations of sodium acetate for concentration and productivity of biomass and lipid, lipid contents (LCs), and fatty acid profiles. The optimum condition was obtained at Day 21 with 10 mM sodium acetate, which gave 6.940 ± 0.057 g L−1 biomass concentration, 327.619 ± 2.020 mg L−1 day−1 biomass productivity, 2.795 ± 0.191 g L−1 lipid concentration, 131.955 ± 9.275 mg L−1 day−1 lipid productivity, and 40.286 % ± 3.079 % w/w LC. The optimum condition (10 mM sodium acetate) in an open pond cultivation attained maximum values at Day 14, that is, 0.575 ± 0.004 g L−1 biomass concentration, 38.161 ± 0.076 mg L−1 day−1 biomass productivity, 0.203 ± 0.002 g L−1 lipid concentration, 13.440 ± 0.197 mg L−1 day−1 lipid productivity, and 35.219 % ± 0.585 % w/w LC. The lipids recovered from mixotrophic micro‐algae were primarily unsaturated fatty acids, which are appropriate to produce biodiesel. The results revealed that a 10 mM sodium acetate concentration can enhance lipid accumulation within algal cells.

Designing biphasic nanocellulose hydrogels to mimic the complex cartilage-bone interface

Osteochondral lesions, which affect both the cartilage and the bone, present significant challenges in treatment due to the complex mechanical and biochemical properties of these tissues. A crucial consideration in developing tissue replacements for these lesions is the simultaneous regeneration of cartilage and calcified cartilage, which forms the transition zone to bone. Our current study aims to fabricate a bilayer polymeric hydrogel designed not only to support cartilage regeneration but also to serve as an interface between cartilage and bone. The bilayer hydrogel was created by combining oxidized bacterial nanocellulose, gelatin, and alginate in one layer, while the other layer consisted of the same three biopolymers and hydroxyapatite. The bacterial nanocellulose was effectively oxidized (20%) with sodium periodate and then mineralized with calcium and phosphorus (Ca/P ratio = 0.97), as confirmed by EDX analysis. Remarkably, both layers of the biphasic hydrogel demonstrated cytocompatibility with chondrocytes. Moreover, the addition of hydroxyapatite significantly improved the mechanical strength from 72 kPa (OBC/Gel/Alg) to 90 kPa (MOBC/Gel/Alg). This bilayer hydrogel holds promise for promoting bone-cartilage integration and has the potential to contribute to the healing of osteochondral defects, offering new possibilities in the field of orthopedic tissue engineering and regenerative medicine.

Customising Sustainable Bio-Based Polyelectrolytes: Introduction of Charged and Hydrophobic Groups in Cellulose

Cellulose has been widely explored as a sustainable alternative to synthetic polymers in industrial applications, thanks to its advantageous properties. The introduction of chemical modifications on cellulose structure, focusing on cationic and hydrophobic modifications, can enhance its functionality and expand the range of applications. In the present work, cationization was carried out through a two-step process involving sodium periodate oxidation followed by a reaction with the Girard T reagent, yielding a degree of substitution for cationic groups (DScationic) between 0.3 and 1.8. Hydrophobic modification was achieved via esterification with fatty acids derived from commercial plant oils, using an enzyme-assisted, environmentally friendly method. Lipase-catalysed hydrolysis, optimised at 0.25% enzyme concentration and with a 1 h reaction time, produced an 84% yield of fatty acids, confirmed by FTIR and NMR analyses. The degree of substitution for hydrophobic groups (DShydrophobic) ranged from 0.09 to 0.66. The molecular weight (MW) of the modified cellulose derivatives varied from 1.8 to 141 kDa. This dual modification strategy enables the creation of cellulose-based polymers with controlled electrostatic and hydrophobic characteristics, customisable for specific industrial applications. Our approach presents a sustainable and flexible solution for developing cellulose derivatives tailored to diverse industrial needs.

Improving separation efficiency of various micropollutants from water by polymer-enhanced ultrafiltration using oxidized alginate featuring less viscous and low filtration resistance

Polymer-enhanced ultrafiltration (PEUF) is an economical and energy-efficient alternative using a versatile water-soluble polymer (WSP) to remove micropollutants by electrostatic interactions, allowing size exclusion through ultrafiltration (UF) membranes due to the WSP being bigger than the pores of UF membranes. However, the WSP used in PEUF is so viscous that it inevitably causes significant filtration resistance and membrane fouling, reducing filtration and energy efficiency. To overcome this problem, in this study, sodium alginate (Alg), which significantly performs in removing cationic pollutants, was oxidized using sodium periodate to produce oxidized alginate (OxAlg). The retention and water flux profiles of OxAlg for three micropollutants, methylene blue (MB), ciprofloxacin, and tetramethylammonium hydroxide, using the PEUF method were investigated in terms of pH, ionic strength, polymer and pollutant amount. A comparison between Alg and OxAlg demonstrated 1.19% to 1.8% higher MB retention rates (99.31%-99.97%) and up to 4.07 times higher water flux depending on the amount of polymer added. Furthermore, OxAlg displayed excellent retention rates of the NF level and 20-60 times higher water flux than typical NF. This outstanding OxAlg performance was mainly due to OxAlg’s properties, such as the low viscosity, flexibility and the resulting accessibility, and appropriate size from the perspective of filtration. Lastly, OxAlg was found to have the potential to surpass the existing WSP in that it showed a higher maximum retention capacity than about 560 to 1250mg/g in the real-world pH enrichment test even before the saturation.

Recrystallizing Sputtered NiOx for Improved Hole Extraction in Perovskite/Silicon Tandem Solar Cells

AbstractSputtering nickel oxide (NiOx) is a production‐line‐compatible route for depositing hole transport layers (HTL) in perovskite/silicon tandem solar cells. However, this technique often results in films with low crystallinity and structural flaws, which can impair electronic conductivity. Additionally, the complex surface chemistry and inadequate Ni3+/Ni2+ ratio impede the effective binding of self‐assembled monolayers (SAMs), affecting hole extraction at the perovskite/HTL interface. Herein, these issues are addressed using a recrystallization strategy by treating sputtered NiOx thin films with sodium periodate (NaIO4), an industrially available oxidant. This treatment improved crystallinity and increased the Ni3+/Ni2+ ratio, resulting in a higher content of nickel oxyhydroxide. These enhancements strengthened the SAM's anchoring capability on NiOx and improved the hole extraction at the perovskite/HTL interface. Moreover, the NaIO4 treatment facilitated Na+ diffusion within the perovskite layer and minimized phase separation, thus improving device stability. As a result, single‐junction perovskite solar cells with a 1.68 eV bandgap achieve a power conversion efficiency (PCE) of 23.22% for an area of 0.12 cm2. Perovskite/silicon tandem cells with an area of 1 cm2 reached a PCE of 30.48%. Encapsulated tandem devices retained 95% of their initial PCE after 300 h of maximum power point tracking under 1‐sun illumination at 25 °C.

NaIO4/NH2OH-mediated Efficient Synthesis of Phosphoroamidates from Anilines and Triethyl Phosphite

AbstractA simple, efficient, and metal-free method was developed for the synthesis of phosphoroamidates. In essence, a mixture of sodium periodate (NaIO4) and hydroxylamine (NH2OH⸱HCl) was used in stoichiometric amounts to execute the phosphoramidation reaction of aromatic amines and triethyl phosphites at room temperature, in open air. This method offers a practical synthesis route to afford a diverse range of phosphoroamidates via the construction of P − N bonds, with excellent functional group compatibility and good yields under mild conditions.

Schiff base approach to introduce chitosan-phytic acid complex for flame-retardant cotton fabrics

In this study, chitosan was integrated onto cotton fabric fibers through a Schiff base reaction, followed by the in-situ generation of Chitosan-Phytic acid (CH-PA) complex to achieve green flame retardancy. The process began with oxidizing the fabric using sodium periodate (NaIO4) to create numerous aldehyde groups on the fiber surface. Subsequently, CH was grafted onto the fabric via a Schiff base reaction. The fabric was then immersed in a PA solution to form a CH-PA complex, resulting in a novel and highly efficient flame-retardant (FR) fabric. The structure of the treated fabric was analyzed by using Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS), confirming the successful formation of the desired structure. The thermal stability and flame retardancy of the fabric were systematically evaluated using thermogravimetric analysis (TGA), cone calorimetry (CONE), vertical combustion tests, and limiting oxygen index (LOI) measurements. The LOI increased from 17.6 % to 30.6 %, and vertical combustion tests demonstrated self-extinguishing capabilities when the fabric was treated by the NaIO4 solution at concentrations of 0.02 g/mL or higher. In the CONE test, the modified fabric showed significant improvements, with peak heat release rate (pHRR) and total heat release (THR) decreasing by approximately 80 % and 60 %, respectively. Comprehensive analysis indicated that the FR mechanism involved both gas phase and condensed phase actions. Further characterization of the material included tensile testing and wash resistance assessments. By comparing these findings with recent research on similar topics, the advantages and disadvantages of the materials were thoroughly evaluated. Notably, this work provides a robust experimental foundation and conceptual expansion for the green flame retardancy of cotton fabrics.

Sorption properties of a new modified flax fibre sorbent

The purpose of this study is to develop a modified sorbent of flax waste and investigate its sorption properties towards Cu (II) ions. The authors conducted the modification in two steps. The first step was oxidation of flax fibre cellulose with sodium metaperiodate to dialdehyde cellulose, the second one was the addition of taurine to increase the sorption characteristics of the modified sorbent. The paper presents the conditions for the periodate oxidation reaction of flax fibre and the treatment of the resulting dialdehyde cellulose with taurine. We determined the sorption characteristics of the modified sorbent in comparison with the original flax fibre. Kinetic studies allowed us to establish the time of reaching sorption equilibrium in the heterophase system ‘aqueous solution of metal salt-sorbent’ and determine the reaction order using pseudo first and pseudo-second order kinetics models. The authors processed the sorption isotherms obtained during the experiments using the Langmuir model. The maximum sorption capacity increased by 3 times compared to the original flax fibre. IR spectroscopy confirmed the improvement of equilibrium and kinetic characteristics of flax fibre occuring as a result of the appearance of new sorption centres in its structure.

SYNTHESIS OF CHITOSAN COMPOSITES WITH METHYLENE BLUE, MALACHITE GREEN AND ACID FUCHSIN DYES FOR ENHANCEMENT OF THEIR ANTIMICROBIAL ACTION

The effect of chitosan oxidation with sodium periodate on the ability to form complexes with the dyes methylene blue, malachite green and acid fuchsin, which have an antiseptic effect, was investigated. A non-covalent interaction occurred for methylene blue and malachite green, while a covalent interaction occurred for acid fuchsin. Fourier-transform infrared spectroscopy confirmed the formation of chitosan composites with these dyes. The antimicrobial effect of these dyes complexed with oxidised chitosan against Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and Escherichia coli was investigated. The non-covalent attachment of malachite green and methylene blue to chitosan preserved their antimicrobial effect; hence, complexes of these dyes with oxidised chitosan provide a more convenient form that is less staining. However, the covalent conjugation of acid fuchsin with oxidised chitosan caused a significant loss of the antimicrobial activity. The developed method of conjugation of specific dyes with chitosan can be used to create complexes of this biopolymer with a wide range of biologically active organic substances.

Thiolated dextrin nanoparticles for curcumin delivery: Stability, in vitro release, and binding mechanism

To achieve the effective loading and delivery of curcumin, novel disulfide-crosslinked nanoparticles based on modified dextrin were developed for the encapsulation of curcumin. Thiolated dextrin (Dt-SH) was obtained via sodium periodate oxidation and cysteamine grafting. The Dt-SH exhibited a rough, flake-like morphology, was classified as an amorphous material and demonstrated enhanced enzyme resistance. Subsequently, spherical nanoparticles with sizes ranging from 92.52 to 157.12 nm and zeta potentials between +23.59 and + 29.90 mV were self-assembled in an aqueous solution. Thiol modification promoted interconnection and aggregation of the nanoparticles. These nanoparticles exhibited pH-dependent size variations. Taking curcumin as a hydrophobic model, nanoparticles showed intestinal targeted release in vitro. Fluorescence spectroscopy and thermodynamic analysis indicated that curcumin bound to Dt-SH nanoparticles primarily through hydrogen bonding and van der Waals forces, with hydrophobic interactions contributing. These findings supported the potential of thiolated dextrin nanoparticles in the effective delivery of hydrophobic compounds.

Study on flotation behavior and mechanism of galena flotation separation from chalcopyrite by sodium periodate depressant

The successful separating galena and chalcopyrite by flotation presents difficulties owing to their analogous surface chemical properties. This study investigated sodium periodate (SP) as a novel depressant for selectively oxidizing and modifying chalcopyrite and galena surfaces, enabling successful flotation separation. In micro-flotation tests were carried out at pH 8.5 and SP concentration of 5 × 10−4 mol/L. The grades of Cu and Pb in the copper concentrate were 27.87 % and 23.13 % with recoveries of 81.22 % and 27.78 %, respectively. SP selectively inhibited galena floatability while preserving chalcopyrite floatability. The selective depression mechanism research of SP in flotation separation process showed that galena surface hydrophobicity was significantly reduced by SP, which in turn prevented the collecting agent from adhering to galena. In the presence of SP, hydrophilic species such as PbSO4 and Pb(OH)2 were generated on the surface of galena, which decreased its ability to float. Conversely, on the chalcopyrite surface, hydrophobic products such as CuS2, CuSn, and S0 were formed, having little effect on its floatability. A model was developed to elucidate the mechanism underlying the selective flotation separation of the chalcopyrite and galena using SP.

New insights into the quantiffcation of Fe(IV) using methyl phenyl sulfoxide (PMSO) as probe in the iron-based heterogeneous catalyst activated persulfate process

Ferryl ions (Fe(IV)) are often thought to play an important role in iron-based advanced oxidation processes (AOPs), and their presence is typically inferred through the unique pathway of methyl phenyl sulfoxide (PMSO) conversion to methyl phenyl sulfone (PMSO2). Here, we first employed probe method by degrading the mixed system containing PMSO, benzoic acid (BA), nitrobenzene (NB) to analyze the steady-state concentration of Fe (IV) in the iron-based heterogeneous persulfate reaction system. In addition, studies were conducted on the direct oxidation of PMSO by different oxidants under different pH conditions, and the results showed that peroxymonosulfate (PMS), sodium hypochlorite (NaClO) and sodium periodate (PI) can directly oxidize PMSO and convert it into PMSO2. Furthermore, the influence of different types of iron salts and biomass on the prepared iron-biochar (Fe-BC) for the activation of persulfate on degradation of PMSO and the formation of PMSO2 was also investigated. This study may provide new insights into the use of PMSO as a probe for the analysis of Fe(IV) in heterogeneous reaction systems.

Preparation and characterization of polymeric cellulose wood adhesive with excellent bonding properties and water resistance

Developing the most abundant cellulose resources in nature as wood adhesives is a challenging but significant work. In this study, an oxidized cellulose-hexamethylene diamine-urea (OCHU) resin adhesive, of high bonding performance, and excellent water resistance has been prepared. The cellulose was firstly enzymatically hydrolyzed to increase its solubility and expose more hydroxyl groups, then oxidized by sodium periodate (NaIO4) to generate a biological compound being rich of aldehyde groups. The OCHU adhesive was prepared by crosslinking oxidized cellulose (OC) with a synthetic reactive polyurea (HU) polymer, which was formed through the deamidation reaction between hexamethylenediamine (H) and urea (U). This adhesive exhibited a 24 h cold water soaking strength of 1.61 MPa, 3 h hot water (63 °C) strength of 1.05 MPa and a dry strength of 1.71 MPa. Compared to oxidized cellulose-hexamethylenediamine (OCH) adhesive, a significant increase of 60 % in this adhesive's wet strength. The Schiff base and addition reactions in the preparation were confirmed by XPS, solid-state NMR, and FTIR. This cellulose-based wood adhesive has great market competitiveness for mass production and application in the plywood industry, due to its excellent bonding properties.

A bio-based soy wood adhesive modified by dual-crosslinking strategy with excellent mechanical strength and water-resistance

Soy-based adhesives have garnered significant attention owing to their distinctive environmentally sustainable characteristics and low cost. However, they exhibit inadequate bonding strength and water-resistance, which can be attributed to the presence of polar groups in soy flours. Herein, a simple and eco-friendly dual-crosslinking strategy was proposed to manufacture a soy-based adhesive (SF/IO4/CA adhesive) with excellent mechanical properties and good water-resistance. Specifically, soy flours were treated with sodium periodate (NaIO4) for oxidization, which facilitated the soy flours' self-crosslinking process by converting carbohydrates into components having the cross-linking action (internal cross-linking agents). Then, incorporating the citric acid (CA) would promote to the carboxyl groups (-COOH) of CA to react with the hydrophilic hydroxyl groups (-OH) present in soy flours by esterification reaction. The findings demonstrated that a high-performance plywood using SF/IO4/CA adhesive was successfully produced, which shear strength of cold-water (20 °C for 24 h), hot-water (63 °C for 3 h), and boiling-water (93 °C for 3 h) reached 1.69 MPa, 1.68 MPa, 1.72 MPa, and 1.47 MPa, respectively. The soy-based adhesive has excellent mechanical strength and water-resistance due to its dual-crosslinking network system, which has significant promise for application use in the wood-based panels industry.

CRUDE INULIN DERIVED FROM DAHLIA TUBER AS NANOMATERIAL AND ITS CHARACTERIZATION

Objective: Dahlia tuber (Dahlia sp.) is one of the inulin sources that could be planted in Indonesia. Inulin is fructan-based polysaccharide. Therefore, the research aimed to investigate inulin from the extract of dahlia tuber as a drug excipient, especially for nanoparticles based on inulin-cysteamine thiomer. Methods: Crude inulin was isolated from dahlia tuber using ethanol for maceration. The resulting inulin was characterized using FT-IR and oxidized using sodium periodate (NaIO4) to increase solubility. Afterward, the oxidized crude inulin was further modified by conjugation with cysteamine to produce a cationic thiomer using reductive amination. The thiomer was evaluated regarding the number of thiol groups and solubility. The nanoparticles were prepared using ionic gelation methods. The resulting nanoparticles were evaluated for particle size and zeta potential. Results: Inulin can be isolated from dahlia tuber with its content of 18.60±4.45% and carbohydrate of 61.75±0.75%. Crude inulin can be conjugated with cysteamine to generate a cationic thiomer using NaCNBH3 as a reductant, which can increase its solubility with free thiol group content of 415.21±40.39 µmol/g. Nanoparticles were generated from crude inulin-cysteamine thiomer with sodium tripolyphosphate (NaTTP), leading to a particle size of 180 nm and zeta potential of-10.8 mV. Conclusion: As a potential nanoparticulate drug delivery system, a cationic thiomer could be synthesized from inulin derived from dahlia tuber grown in Indonesia.

Enhancing Si1-XGex/Si Etch Rate Selectivity Using Etching Inhibitor in Radical Oxidation By Halide-Based Oxidant

As the technology node shrinks, innovation in the metal-oxide-semiconductor field-effect transistor (MOSFET) architecture has been required to mitigate the short-channel effects (SCE). Thus, planar FET had changed to FinFET and now gate-all-around FET (GAAFET) has been introduced with entering the 3-nm-generation. To fabricate GAAFET, selective etching of Si1-xGex- to Si-film is a key technology. According to the International Roadmap for Devices and Systems (IRDS™), the gate width of GAAFET is around 30 nm. Therefore, higher than 30 nm/min of etch rate for throughput and more than 400:1 of selectivity for acquiring a uniform Si-channel layer are required.As is well known, the etch rate in wet etching strongly depends on the standard reduction potential (SRP) of the oxidant. Our research group previously revealed the radical oxidation mechanism of sodium periodate (NaIO4) oxidant. In an acidic medium, NaIO4 can exist in periodate ion (IO4 -) form capable of generating hydroxyl radical (•OH). The high SRP value of hydroxyl radical (2.80 eV) compared to conventional oxidant, hydrogen peroxide (H2O2, 1.76 eV) and peracetic acid (PAA, 1.75 eV), resulted significantly high etch rate. In subsequent research, we introduced inhibitors reducing the Si-film etch rate to enhance Si1-xGex/Si etch rate selectivity when using sodium periodate as an oxidant.Acetic acid is commonly used as an additive in wet etchants to maintain uniform pH and control the etching of Si-film. However, it has several issues, strong vinegar odor, relatively large concentration to act, etc. Therefore, other additives are needed to substitute acetic acid. In selecting inhibitors, 2 factors are considered, i) scavenging effect for hydroxyl radical, and ii) hydrophobicity, as shown in Figure 1. Because the concentration of hydroxyl radical influences not only the Si1-xGex-film etch rate, but the Si-film etch rate, the scavenging effect of an inhibitor can reduce the film etch rate to enhance etch rate selectivity. Furthermore, the hydrophobicity part of inhibitors can build a hindrance layer on Si-film. Generally, Si-film has more hydrophobicity than Si1-xGex-film, inhibitors having hydrophobicity part are more prone to form a hindrance layer on Si-film than Si1-xGex-film. This results in the enhancement of Si1-xGex/Si etch rate selectivity by reducing Si-film considerably than Si1-xGex-film. The qualitative comparison of hydroxyl radical concentration depending on inhibitors and characterization methods to confirm the hindrance layer will be presented in detail. Acknowledgement This work was supported by the Technology Innovation Program (20022475, Development of wet Etchant capable of high selection etching in microprocesses below 10 nm) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea) References [1] Lee, Seung-Jae, et al. "Extremely high selective Si1−xGex-film wet etchant generating highly dissolved oxygen via peracetic acid oxidant for lateral gate-all-around FETs with a logic node of less than 3-nm." Chemical Engineering Journal 475 (2023): 146257. Figure 1

Preparation of a starch derivative bearing chloroaniline groups and the evaluation of its hemolytic, cytotoxic and antibacterial activities

AbstractA new starch derivative with antibacterial properties and non‐hemolytic effect was synthesized through the chemical grafting of 4‐chloroaniline onto the backbone of potato starch. In a first step, starch was extracted from potatoes grown in the region of Coahuila, Mexico, using the water steeping method. The hydroxyl groups (C5‐C6) of the native starch were oxidized using sodium periodate. The resulting dialdehyde was then chemically modified through a Schiff base reaction with 4‐chloroaniline. The chemical structure of this starch derivative was confirmed by Fourier transform infrared and 1H NMR spectroscopies, the thermal properties were analyzed by thermogravimetric analysis without finding significant changes and the product showed antibacterial activity against Gram‐negative E. coli and Gram‐positive S. aureus strains. Finally, the hemolytic and cytotoxic effects of native starch and its derivative were studied, showing no hemolytic effect on isolated human red blood cells and no cytotoxic effect; therefore, it can be considered biocompatible. © 2024 Society of Chemical Industry.

Facile preparation of interpenetrating network hydrogel adsorbent from starch- chitosan for effective removal of methylene blue in water

Hydrogels based on biopolymers have attracted considerable interest in the last decades. Herein, an interpenetrating network hydrogel (IPN-Gel) adsorbent from starch-chitosan was fabricated facilely in one-pot through tandem Schiff base reaction and photopolymerization. First, aldehyde starch (DAS) was synthesized by the reaction of soluble starch with sodium periodate. Afterward, acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), polyethylene glycol dimethacrylate (PEGDMA), photoinitiator, chitosan and DAS were dissolved in water to obtain a clear solution. Schiff base reaction between chitosan and DAS took place quickly to form the first network, and then photopolymerization of AM, AMPS, and PEGDMA occurred under ultraviolet radiation to form the second network. The preparation conditions of the as-prepared IPN-Gel were optimized with two indexes of gel mass fraction and swelling ratio. Its swelling behavior with pH and temperature change was explored. Finally, its adsorption performance was characterized with methylene blue (MB) as a model contaminant. The maximum adsorption capacity of IPN-Gel can reach 2039 mg·g−1 at pH =10. Its adsorption performance accords with Langmuir isothermal model and pseudo-second-order kinetic model and it was mainly controlled by chemisorption. This strategy is expected to found broad application prospects in the preparation of hydrogel adsorbents.