Impregnation Time Research Articles

Research on Optimization of Impregnation Conditions of Eucalyptus Veneer with Modification of Fire Retardancy

The waterborne composite modifier was employed to treat Eucalyptus veneer to obtain fire retardancy. By response surface methodology (RSM), the effects of vacuum time, impregnation pressure, and impregnation time were investigated. The optimized impregnation conditions were obtained through RSM. The vacuum time, impregnation pressure, and impregnation time were 39 min, 0.9 MPa and 79 min, respectively. After validation test, under the optimized conditions, the average LOI of Eucalyptus veneer was 28.2% with the percentage error 4.49%. Therefore, this predictive model for the preparation of treated Eucalyptus veneer was accurate and reliable for practical manufacturing. Moreover, the SEM analysis illustrated that the cavity of wood was filled with modifier after impregnation under optimized conditions.

Optimization of nutrients removal from synthetic greywater by low-cost activated carbon: application of Taguchi method and response surface methodology

This study considered the experimental parameters (zinc chloride, impregnation ratio and activation times) for nutrients removals (nitrate and phosphate) in synthetic greywater using activated carbon from banana trunk via Taguchi and response surface methodology (RSM). Lastly, the best optimization method was selected to optimize the experimental parameters for nutrient removal in synthetic greywater. For Taguchi method, the most influential experimental parameter was zinc chloride (ZnCl2), followed by impregnation ratio and activation time for both nitrate and phosphate removals. ANOVA results in Taguchi method found that ZnCl2, impregnation ratio, and activation time were significantly associated with phosphate removal. Only ZnCl2 and impregnation ratio were significantly associated with nitrate removal. Response Surface Methodology (RSM) adopting Box–Behnken Design findings indicated that ZnCl2 and impregnation time were the significant experimental parameters for nitrate removal. While, ZnCl2, impregnation ratio and activation time were significantly associated with phosphate removal in synthetic greywater. Three-dimensional surface plots illustrated that the nutrients removals (nitrate and phosphate) increase with the increasing of experimental parameters (ZnCl2, activation time, and impregnation ratio). The RSM method via Box–Behnken Design was chosen as it considered possible linear and non-linear combination interactions between two or more parameters with low errors.

Optimization of Mixed Fermentation Technology of Chardonnay and Cabernet Sauvignon by Response Surface Methodology

Based on chardonnay and Cabernet Sauvignon as raw materials, the effect of material ratio, impregnation temperature and impregnation time on the quality of mixed rose wine were studied. The fruit pulp of chardonnay and Cabernet Sauvignon was mixed in a certain proportion and impregnated, and the juice was separated and fermented. On the basis of single-factor experiments, the addition ratio, impregnation time and impregnation temperature of chardonnay and Cabernet sauvignon were used as the independent variables, the response value was used to be scored by sensory scoring, and technical parameters of rose wine were optimized by the response surface analysis, and its physical and chemical indicators were detected. The results showed that the optimal impregnation technology parameters was material ratio 1:1, impregnation time 21 h, impregnation temperature 22 ℃, under which the sensory score of rose wine reached 91.00 points, the alcohol content was 12.8% vol, and the total sugar content (in glucose) was 3.69 g/L, total acid content (in tartaric acid) was 5.42 g/L, the content of anthocyanin was 93.4 mg/L, the physical and chemical indicators were in line with national standards, the wine body was rose-red, wine fragrance rich, and had more refreshing taste.

Production and Characterization of Activated Carbon from Dashen Brewery Gondar Spent Label as Precursor

The purpose of this work is to identify a precursor from brewery industry waste to produce activated carbon and the same could be used for the treatment of brewery inlet water. Among the wastes generated in the industry, it was found that spent label paper has good potential as precursor since it has good cellulose content. One more attractive feature of this spent label is that it is in-house generated waste and is available at free of cost. The activated carbon was prepared by following chemical activation process. The various activation agents like potassium chloride, phosphoric acid, potassium hydroxide and Zinc chloride were used as the chemical activation agent and their effect on Iodine value and the yield and was studied. A methodical study of the effect of concentration of activation agent, impregnation time, activation temperature and activation time on the iodine value and the yield % during the production of activated carbon from spent label was studied. The prepared activated carbon was characterized by measuring the iodine number and yield percentage. The apparent density of the chemically activated carbons was examined and found to be 0.43 g/ml. Also, the adsorption power of the prepared activated carbon was checked by using methylene blue. During the test it was visually observed that the color intensity reduced enormously, which is an indication that the product was successfully activated. The optimum conditions for the production of activated carbon are a 2 N concentration of zinc chloride activating agent with 20 h of impregnation time and at a activation temperature of 600oC for an activation time of 1 h gave rise to an iodine number of 734.7 mg/g, which is relatively a good number.

Utilization of Citrus aurantium peels for sustainable production of high surface area type I microporous nano activated carbons

Orange (Citrus aurantium) peel was investigated for producing microporous nano activated carbons (OPAC). One-step chemical activation process by zinc chloride as an activating agent and a carbonization temperatures ranging from 500 to 900 °C was used to produce OPAC having high surface area of type I. The effects of carbonization temperature, impregnation ratio, and impregnation time on the properties of the OPAC were studied. The prepared activated carbons were characterized by FTIR; Brunauer–Emmett–Teller (BET); TGA; TEM, SEM, and EDAX analyses; the point of zero charge; and Boehm titration method. The maximal surface area of OPAC was activated by using the impregnation (orange peel/ZnCl2) ratio of 2:1, 700 °C carbonization temperature, and a 30-min holding time. The BET surface area, the total pore volume, and the micropore volume were 1228.2 m2/g, 0.5516, and 0.5482 cm3/g, respectively. The total pore volume increased with the increase of the activation temperature. The minimum pore diameter was 0.7 nm and the mean pore diameter was 1.797 nm. The results proved that the ZnCl2 chemical activation is a useful technique to prepare high surface area activated carbon from Citrus aurantium peels with nano pore size structure.

Сhemical processing of corn head wrappers on fiber semi-finished products

Non-woody plant raw materials are of scientific interest in the effective processes of their chemical processing into fibrous semi-finished products and the properties of the finished product. A feature is the study of local species of annual plants that are among the most cultivated. Therefore, scientists are increasingly experimenting with corn waste for the possibility of their use in the manufacture of paper or cardboard, the study of their properties, but the results are not always stable.
 Our work focuses on the use of corn waste in the form of cob wrappers and obtaining from them fibrous semi-finished products by the soda-soda method. The restraining factor of obtaining cellulose from this raw material is the variability of chemical composition, features of morphological structure, the insufficient study of delignification depending on the cost of active alkali, the influence of impregnation on this process, its duration, and temperature.
 Wraps in the form of chaff were boiled with a solution at the consumption of active alkali 6 %, 10 %, and 14 % in units. Na2O by mass abs. dry. raw materials for impregnation for 15 min or without impregnation and subsequent cooking at a final temperature in the range of 100 0C - 160 0C for 15 or 30 min. The semi-finished products obtained as a result of cooking were ground, samples were made and their strength indicators were determined. It should be noted that the wrappers contain about twice less lignin, about 7.5-14 %, compared to wood – 23-28 %, which led to the choice of the minimum duration of cooking. However, the semi-finished products obtained from them are difficult to grind. This pattern is partly explained by the location of fibrils in the secondary wall of the middle layer S2 at an angle of 45-500 to the fiber axis, and the direction of fibrils in adjacent layers S1 and S3 of the cell wall is opposite, which inhibits splitting into individual fibrils.
 It is shown that impregnation has a positive effect on the quality of raw material digestion and physical and mechanical properties. At a temperature of 130 0C for only 15 and 30 minutes of cooking with impregnation and the consumption of active alkali 14 % in units. Na2O achieved high strength of semi-finished products. Increasing the cooking temperature to 160 0C and the maximum consumption of active alkali to 14 % per unit. Na2O leads to a sharp decrease in the yield and strength of semi-finished products. This pattern is logically explained by theoretical provisions on the processes of delignification of raw materials. At the same time, the temperature and the consumption of alkali increase the destruction of the carbohydrate part, primarily its low-molecular fractions, which are responsible for the formation of strong hydrogen bonds between the fibers. The optimal conditions for delignification at a temperature of 160 0C can be considered the consumption of active alkali 10 % per unit. Na2O with impregnation and cooking time of 15 minutes and obtaining high yield cellulose.
 The proposed raw materials for corn cob wrappers and technological modes of its chemical processing provide the production of fibrous semi-finished products with high strength.

A Comparative Study of Pellet-Based Extrusion Deposition of Short, Long, and Continuous Carbon Fiber-Reinforced Polymer Composites for Large-Scale Additive Manufacturing

Abstract Pellet-based extrusion deposition of carbon fiber-reinforced composites at high material deposition rates has recently gained much attention due to its applications in large-scale additive manufacturing. The mechanical and physical properties of large-volume components largely depend on their reinforcing fiber length. However, very few studies have been done thus far to have a direct comparison of additively fabricated composites reinforced with different carbon fiber lengths. In this study, a new additive manufacturing (AM) approach to fabricate long fiber-reinforced polymer (LFRP) was first proposed. A pellet-based extrusion deposition method was implemented, which directly used thermoplastic pellets and continuous fiber tows as feedstock materials. Discontinuous long carbon fibers, with an average fiber length of 20.1 mm, were successfully incorporated into printed LFRP samples. The printed LFRP samples were compared with short fiber-reinforced polymer (SFRP) and continuous fiber-reinforced polymer (CFRP) counterparts through mechanical tests and microstructural analyses. The carbon fiber dispersion, distribution of carbon fiber length and orientation, and fiber wetting were studied. As expected, a steady increase in flexural strength was observed with increasing fiber length. The carbon fibers were highly oriented along the printing direction. A more uniformly distributed discontinuous fiber reinforcement was found within printed SFRP and LFRP samples. Due to decreased fiber impregnation time and lowered impregnation rate, the printed CFRP samples showed a lower degree of impregnation and worse fiber wetting conditions. The feasibility of the proposed AM methods was further demonstrated by fabricating large-volume components with complex geometries.

Fabrication, characterization, and adsorption applications of low-cost hybride activated carbons from peanut shell-vinasse mixtures by one-step pyrolysis

The present work aims to develop an innovative, alternative, fast, and cost-effective one-step pyrolysis method for activated carbon production using peanut shell and vinasse mixture. This facile procedure is based on single-step carbonization treatment at a temperature range of 400–800 °C. Different carbonization time (15–360 min), impregnation ratio (1–3 g/g), impregnation time (3–24 h), and nitrogen flow rate (300 and 600 ml/min) were examined. The chemical and physical properties of the activated carbon examined by SEM-EDX, FT-IR analysis, particle size distribution, iodine number, pHzpc, BET surface area, and surface functional group analysis by Boehm’s titration. The results illustrate that the values of BET surface area, total pore volume, average pore diameter, iodine number, pHzpc, and carbon content of activated carbon were found as 1290.5 m2/g, 0.5667 cm3/g, 21.2 A, 1258.4 mg/g, 5.7, and 86.89%, respectively.

Preparation and characterization of groundnut shell-based activated charcoal

Groundnut shell, an agricultural waste was used as a precursor for the preparation of activated charcoal using zinc chloride as a chemical activating agent. The results of the optimization studies showed that the activated charcoal had best iodine adsorption capacity at 1.0 mol dm-3 activator’s concentration, 2:1 impregnation ratio, 70 ℃ impregnation temperature, 12 hr impregnation time, 500 ℃ activation temperature, and 2hr activationtime. The surface chemistry of the adsorbent was studied by Fourier transform infra-red spectroscopy and scanning electron microscopy–energy dispersive X-ray spectroscopy. The activated charcoal was found to contain porous structures with adsorption capacities significantly correlated with iodine value, porosity, and surface area. The surface morphology of the activated charcoal was altered as compared with the un-activated product, signifying that the adsorbent had been chemically modified. The disappearance of some functional groups and shift in some absorption bands were further indication that surface structural modification took place during activation and carbonization.This research has revealed that groundnut shell could be employed for the production of an alternative adsorbent which can be utilize for filtration and detoxification of impure water, treatment of effluent and wastewater, adsorption of pesticides, heavy metals and dyes from aqueous media.

Changes in Flexural Strength and Electrical Resistivity of Bulk Graphite According to the Viscosity of Impregnant

In the manufacturing of bulk graphite, pores produced by vaporization and discharge of volatile materials in binders during carbonization reduce the density of bulk graphite, which adversely affects the electrical conductivity, strength and mechanical properties. Therefore, an impregnation process is introduced to fill the pores and increase the density of bulk graphite. In this study, bulk graphite is prepared by varying the viscosity of the impregnant. The microstructure of bulk graphite is observed. The flexural strength and electrical resistivity are measured. As the viscosity of the impregnants decreases and the number of impregnations increases, it is shown that the number of pores decreases. The density before impregnation is 1.62 g/cm3. The density increases to 1.67 g/cm3 and porosity decreases by 18.6 % after three impregnations using 5.1 cP impregnant, resulting in the best pore-filling effect. After three times of impregnation with a viscosity of 5.1 cP, the flexural strength increases by 55.2 % and the electrical resistivity decreases by 86.76 %. This shows that a slight increase in density due to the pore-filling effect improves the properties of bulk graphite.

The Pore-filling Effect of Bulk Graphite According to Viscosity of Impregnant

Pores produced by carbonization in bulk graphite process degrade the mechanical and electrical properties of bulk graphite. Therefore, the pores of bulk graphite must be reduced and an impregnation process needs to be performed for this reason. In this study, bulk graphite is impregnated by varying the viscosity of the impregnant. The pore volume and pore size distribution, according to the viscosity of the impregnant, are analyzed using a porosimeter. The total pore volume of bulk graphite is analyzed from the cumulative amount of mercury penetrated. The volume for a specific pore size is interpreted as the amount of mercury penetrating into that pore size. This decreases the cumulative amount of mercury penetrating into the recarbonized bulk graphite after impregnation because the viscosity of the impregnant is lower. The cumulative amount of mercury penetrating into bulk graphite before impregnation and after three times of impregnation with 5.1cP are 0.144 mL/g and 0.125 mL/gm, respectively. Therefore, it is confirmed that the impregnant filled the pores of the bulk graphite well. In this study, the impregnant with 5.1 cP, which is the lowest viscosity, shows the best effect for reducing the total pore volume. In addition, it is confirmed by Raman analysis that the impregnant is filled inside the pores. It is confirmed that phenolic resin, the impregnant, exists inside the pores through micro-Raman analysis from the inside of the pore to the outside.

Surface Physicochemical Modification of Kenaf Adsorbent for Hydrogen Adsorption Study

In supporting the industrial kenaf plan developed by Malaysian government, this research has extended the use of kenaf as a sorbent to investigate its reliability for hydrogen adsorption system. In satisfying the objective, the effect of impregnation time and the effect of nickel nitrate concentration on hydrogen adsorption has been studied. In addition, to study the adsorption and desorption capability of the modified kenaf on hydrogen adsorption, the regeneration study was also accounted. The kenaf core with the range of particle size in between 300-500µm has been modified through the physicochemical modification by experiencing the carbonization and activation process prior to be impregnated in nickel nitrate solution (Ni(NO3)2). The morphological and elemental studies on the modified-kenaf sorbent have been done with the helped of Variable Pressure Scanning Electron Microscopy (VPSEM) and Energy Dispersive X-Ray (EDX) analyser, respectively. The hydrogen adsorption using the hydrogen adsorption system was controlled at the pressure of 5 bar. The results show that the modified-kenaf sorbent able to improve the hydrogen adsorption as compared to the unmodified-kenaf sorbent. Based on the morphological analysis, the modified-kenaf sorbent contain more micropores compares to the unmodified-kenaf sorbent which help in the adsorption capacity. Besides, the modified-kenaf sorbent has potential to be reused with minimum pressure drop of only 0.207 and 0.109 bar up to second regeneration cycles. This study has revealed that the modified-kenaf material has high capability to be used as hydrogen adsorbent and can be competitive technology over the existing current hydrogen storage technology.

Use of Coffee Beans to Obtain Activated Carbon with Potential Applications as Supercapacitors

Activated carbons (AC) from coffee bean waste were prepared by chemical activation using as activating compounds potassium hydroxide (KOH) and potassium carbonate (K2CO3) respectively, impregnation times of 24 and 48 hours, 600°C and 700°C as temperatures calcination. After that coals samples were synthesized. They were doped with nickel oxide (NiO) in order to modify the electrical properties of the AC. Later they were characterized (physical adsorption of using N2, FT-IR, XRD). The AC/NiO composites were prepared by the chemical method and the electrodes were compacted into pellet forms, which were placed in a two-electrode cell using 2M sulfuric acid (H2SO4) as electrolyte. Activity electrochemical was evaluated by cyclic voltammetry and galvanostatic chronopotentiometry. Finally, the specific capacitance of the supercapacitors (SCS) was determined from AC/NiO. Results of AC/NiO-48-700°C-KOH and AC/NiO-48-700°C-K2CO3 materials showed maximum capacitances of 405.40 and 394.73 F/g respectively.

Improvement of Electrochemical Capacitance of Activated Carbon Electrodes from African Palm Shell Modified with HNO3

Activated carbon electrodes were synthetized from African palm shell with KOH (CK) at 2/1 KOH/biomass mass ratio and treated thermically at 700°C (1056 m2/g). Then CK was modified at different conditions by surface treatment using HNO3/CK impregnation mass ratios 1 and 12, temperatures between 25 – 80°C, impregnation time 1 – 4 h. The performance of electrodes as supercapacitors was evaluated in 1 M H2SO4 using electrical impedance spectroscopy (EIS) and charge/discharge technique (CP). The results showed that the specific capacitance increases upon oxidation (57 F/g up to 89.7 F/g). The highest capacitance was obtained for sample prepared at impregnation ratio 1, 4 h and 25°C (606 m2/g) without increasing the equivalent resistance series significantly. These results were influenced mainly by the increased of nitrogen functional groups rather than specific surface area, which confirm that the surface composition has a high influence on the electrochemical performance.

Optimization of Activated Carbons Prepared from <i>Parinari macrophylla</i> Shells

Plant matter constitutes an important source for producing carbonaceous materials. This work deals with the preparation of active carbons from shells of Parinari macrophylla (agricultural waste in Niger). Physical, chemical and mixed activations are considered. Several parameters of preparation are optimized, as the nature of the activation gas (N2 or CO2, dry and wet), the concentration of the activating agent (H3PO4), the time of impregnation and the pyrolysis temperature program. The active carbons are characterized through their iodine numbers, their specific surface areas and their porous volumes. Active carbons, produced from shells of Parinari macrophylla display iodine numbers up to 599 mg I2/g and specific surface areas up to 727 m2/g. They also show microporous characteristics, with a mean pore diameter, usually, lower than 20 Å and a microporous surface percentage up to 88.7% and a microporous volume percentage up to 82.1%. The microporosity is far more developed for the active carbons produced by chemical activation.

Production of activated carbon from sawdust and its efficiency in the treatment of sewage water

When water is contaminated and rendered unfit for drinking, it is regarded as waste, which leads to water pollution. Several works have been done to control water pollution, yet this topic is still a point of concern up to date. The study involves the production of activated carbon (AC) using sawdust to treat sewage water obtained from Covenant University. The following conditions were investigated; activation time and temperature, activating agent concentration, and impregnation time. The AC was characterized by measuring ash content, iodine value, moisture, and volatile matter content. The optimum activated carbon prepared in this study had iodine of 1628.95 mg/gm, while the minimum activated carbon had an iodine of 470.41 mg/gm. According to standard procedure, the sewage water sample was characterized physio-chemically before and after treatment using activated carbon as an adsorbent. The results obtained indicated considerable improvement in the quality of the water. When optimum activated carbon was used for treatment, pH value changed from 7.7 to 7.10, biochemical oxygen demand (BOD) was reduced from 288 mg/l to 20 mg/l and Total dissolved solids (TDS) reduced from 183.7 mg/l to 16.4 mg/l, Total suspended solids (TSS) reduced 232 mg/l to 15.7 mg/l. When minimum activated carbon was used for treatment, pH value changed from 7.7 to 7.60, BOD was reduced from 288 mg/l to 112.2 mg/l, and TDS reduced from 232 mg/l to 174 mg/l, TSS reduced 183.7 mg/l to 103 mg/l. The results obtained led to the conclusion that the produced activated carbon effectively treats the above-stated water quality parameters.

Preparation, characterization, and in vitro/vivo evaluation of dexamethasone/poly(ε-caprolactone)-based electrode coatings for cochlear implants

With dexamethasone as the model drug and polycaprolactone (PCL) as the carrier material, a drug delivery coating for cochlear electrodes was prepared, to control cochlear fibrosis caused by cochlear implantation. A dexamethasone/poly (ε-caprolactone)-based electrode coating was prepared using the impregnation coating method. Preparation parameters were optimized, yielding 1 impregnation instance, impregnation time of 10 s, and PCL concentration of 10%. The coating was characterized in vitro using scanning electron microscopy, a universal machine, high-performance liquid chromatography, and CCK-8. The surface was porous and uniformly thick (average thickness, 48.67 µm)—with good flexibility, long-term slow drug release, and optimal drug concentration—and was biologically safe. The experimental results show that PCL is an ideal controlled-release material for dexamethasone as a drug carrier coating for cochlear implants.

Гидрофобизация сорбента для нефти на основе хитина и пенополиуретана

Быстрый рост случаев разливов нефти и нефтепродуктов, ведущих к загрязнению водных объектов, мотивирует быструю разработку сорбционных материалов для очистки воды от нефтяных загрязнений. Для эффективного удаления нефтяных загрязнений необходим высоко гидрофобный материал с хорошей нефтеемкостью. В данном исследовании предпринята попытка увеличить гидрофобность сорбционного материала на основе пенополиуретана и хитина (PPU10C) путем его пропитки раствором стеариновой кислоты (СК) с получением гидрофобизированного сорбента (PPU10C-SA). Исследовано влияние времени обработки и концентрации СК на ее содержание в конечном сорбционном материале и на его сорбционную способность по отношению к нефти и воде. Показано, что оптимальные условия для получения гидрофобного материала следующие: концентрация СК - 0,01 г/мл и время обработки 60 мин. При этом нефтеемкость материала достигает 12,54 г/г, а водоемкость составляет 1,44 г/г. Таким образом, гидрофобность модифицированного сорбционного материала увеличена в 4 раза по сравнению с немодифицированным материалом. Полученные результаты свидетельствуют о том, что сорбционный материал, модифицированный стеариновой кислотой, является перспективным сорбентом для эффективной очистки водных сред от их загрязнения нефтью и нефтепродуктами. The rapidly-growing increase in the events of oil spills in the water environment motivates researchers to the fast development of oil sorbents. The oil pollution removal process requires a highly hydrophobic sorption material with suitable oil capacity. This study presents the results of preparing oil sorption material (PPU10C-SA) with improved hydrophobicity which is based on polyurethane foam and chitin sorbent (PPU10C) by impregnating it with the stearic acid (SA) solution. The influence of the impregnation time and concentration of SA on its content in the resulted sorbent and on its sorption capacity in relation to oil and water is studied. It is shown that the optimal conditions for obtaining the improved hydrophobized material are as follows: the concentration of SA - 0.01 g/ml and the impregnation time - 60 min. In this case, the oil capacity of the material reaches 12.54 g/g along with the water capacity of 1.44 g/g. Thus, the hydrophobicity of the modified sorbent has been increased 4 times in comparison with that of the unmodified material. The obtained results indicate that the SA-modified PPU10C-SA oil sorbent can be a promising sorbent for efficient water purification from spills of oil and oil products.

Fabrication and optimization of kaolin/stearic acid composite as a form-stable phase change material for application in the thermal energy storage systems

The intended object of this research was to evaluate the influence of different parameters employed on the form-stable phase change materials (FSPCMs) characteristics, with emphasis on the loading percentage of a phase change material (PCM) into the supporting material layers. A melt impregnation process was established to fabricate the FSPCM composites. Stearic acid (SA), one of the fatty acids included in the vegetable oils, possessed various properties suitable as a renewable PCM and was used to be impregnated into kaolin as the supporting material that comes from the clay-based mineral group. Mesh size of kaolin, PCM mass fraction, impregnation time, and temperature were among the studied parameters that took part in the loading percent optimization predicted by the experimental design method of optimization using MINITAB 16. The loading percentage of SA within the kaolin has resulted in a solution method using N-hexane as the solvent of SA. Furthermore, the impact of the parameters interaction on the PCM loading percentage was also studied, and the significant ones were determined. The results of the review and analysis lead to achieving the optimal condition of the experiment with 75%, 260, 100 min, and 130°C for PCM mass fraction, kaolin mesh size, time, and temperature, respectively. Additional characterization procedures were also done on the pre-selected runs to facilitate the explanation for the features of the prepared FSPCMs, PCM, and the supporting material. Various characterization techniques investigated the BET surface area of kaolin, NMR of SA, the morphology, chemical compatibility, and thermal properties of the SA/kaolin composites. The fabricated composite has latent heat of 149.5 J/g with a melting temperature of 60.1°C. The vice versa event (solidifying) requires 143.9 J/g heat dissipation to be solidified at 51.1°C.

Optimization and characterization of eco-friendly antimicrobial nanocellulose sheet prepared using carbon dots of white mulberry (Morus alba L.).

Carbon dots (C-dots) with antimicrobial activity were synthesized from the white mulberry extract with the aim of fabricating anti-listeria nanopaper using bacterial nanocellulose (BNC). Highly dispersed synthesized C-dots with a size smaller than 10 nm (approximately 4.9 nm) were impregnated into BNC by an ex situ coating method and then mechanical, morphological, UV-protectant and antibacterial activity were assessed. Randomized response surface methodology using a central composite design was applied to investigate the optimized concentration of C-dots in the BNC membrane. An optimized nanopaper including C-dots at a concentration of 530 g L-1 and an impregnation time of 14 h at 30 °C with significant antimicrobial activity on Listeria monocytogenes was designed. The addition of C-dots into BNC significantly increased ultimate tensile strength and decreased strain with respect to breaking BNC. A BNC sheet with high-efficient UV-blocking property was prepared using C-dots. Based on the results, the designed nanopaper shows a substantial capacity with respect to the fabrication of antimicrobial/UV-blocking sheets for food active packaging. © 2020 Society of Chemical Industry.