Addition Of Cellulose Research Articles

Design of a biomimetic cellulose nanofibre-based double information encryption sensor for fingerprint imaging

The development of double encryption system enables information to switch reversibly between “False” and “True”, which helps to ensure information security in the transmission process. Herein, a biomimetic cellulose nanofibre-based double information encryption sensor (CNF-DIES) with an excellent pH response and fluorescence colour-switching performance was prepared with fluorescein isothiocyanate and protoporphyrin IX modified acetylated cellulose nanofibres (ACNF) as the pH response switch and background, respectively. Interestingly, with the addition of cellulose, CNF-DIES can be regarded as both a dye and an ink binder, which can realize direct writing function. The fluorescein grafted to ACNF guaranteed the stability of writing and avoided the “coffee ring” phenomenon. The handwriting written by CNF-DIES processes excellent light/pH double encryption performance. Besides, the film prepared by CNF-DIES can realize high resolution fingerprint imaging. This work demonstrated a strategy for pH-responsive colour-tunable materials for sensors and double information encryption.

Ecofriendly Hydroxyalkyl Cellulose Additives for Efficient and Stable MAPbI3‐Based Inverted Perovskite Solar Cells

Perovskite solar cells (PSCs) have been demonstrated to be one of the most promising technologies in the field of renewable energy. However, the presence of the defects in the perovskite films greatly limits the efficiency and the stability of the PSCs. The additive engineering is one of the most effective approaches to overcome this problem. Most of the successful additives are extracted from the petroleum‐based materials, while the research on the biomass‐based additives is still lagging behind. In this paper, two ecofriendly hydroxyalkyl cellulose additives, i.e., hydroxyethyl cellulose (HEC) and hydroxylpropyl cellulose (HPC), are investigated on the performance of the MAPbI3‐based inverted PSCs. Due to the strong interaction between the hydroxyl groups of the cellulose and the divalent cations of the perovskite, these additives enhance the crystal grain orientation and significantly repair the defects of the perovskite films. Working as the additives, these two cellulose derivatives show a strong passivation ability, which significantly reduces the trap density and improves the optoelectronic feature of the PSCs. Compared with the average power conversion efficiency (PCE) of the control device (19.19%), an enhancement of ~10% is achieved after the addition of HEC. The optimized device (PCE = 21.25%) with a long‐term stability (10:80 h, PCE = 20.93%) is achieved by the incorporation of the HEC additives into the precursor solution. It is the best performance among the PSCs with the cellulose additives up to now. This research provides a novel choice to develop a cost‐effective and renewable additive for the PSCs with high efficiency and excellent long‐term stability.

Unveiling real‐time crystallization with nucleators and thickeners for zinc nitrate hexahydrate as a phase change material

AbstractThe primary challenge of salt hydrates as phase change materials (PCMs) is their high degree of supercooling (∆TSup). Past studies have attempted to alleviate ∆TSupby incorporating nucleators possessing similar lattice structure, without a thorough analysis of the nucleator/PCM interactions. This work presents a novel in‐operando study to visually observe the crystallization process of zinc nitrate hexahydrate (ZNH) in real‐time using suitable nucleators and a thickener. We have introduced a new dataset where zinc acetate dihydrate (ZnAc.2H) has been employed as an additive to ZNH for thermal energy storage (TES). According to our in‐operando study, ZnAc.2H underwent hydrolysis in molten ZNH to precipitate needle‐like ZnO particles, which acted as nucleators for the PCM. In the absence of a thickener, the crystal propagation of ZNH exhibited a preferential directional tendency, whereas incorporation of thickener made the phase change process uniform along all directions. Self‐hydrolysis of ZnAc.2H generated excess water which caused the undesirable effect of broadening the endothermic peak. The addition of carboxymethyl cellulose (CMC) thickener could restrict the activity of excess water and reduce the broadening of the endothermic peak. Differential scanning calorimetry (DSC) revealed that 5 wt% ZnAc.2H additive and 2 wt% CMC thickener added to ZNH can considerably improve the TES properties of ZNH PCM (∆HFusion125.9 J·g−1, ∆TSup3.0°C, melting point [M.P.] 29.0°C). Our in‐operando studies can unveil real‐time phase change behaviors to better design PCM systems with desired characteristics.

The effect of cellulose on the combustion characteristics of coal slime: TG-FTIR, principal component analysis, and 2D-COS

Facing the severe environmental and energy crisis, how to use solid waste cleanly and efficiently is imminent. In this study, coal slime and cellulose are used for co-combustion experiments. Coal slime and cellulose are tested at mass ratios of 10:0, 9:1, 7:3, 5:5, 3:7, 1:9, and 0:10. When 10 % cellulose is added to the coal slime, the ignition temperature decreases by 169.3 °C, and the ignition characteristic index increased by 2.9 times. The addition of cellulose makes the comprehensive combustion performance of the sample increase exponentially. By analyzing the dominant reaction in the co-combustion process of coal slime and cellulose, the variance contribution rates of the first principal component and the second principal component are 67.84 and 29.18 %, respectively. Co-combustion of coal slime and cellulose enhances the release and combustion of early volatiles. In addition, the evolution law of gaseous products and the temperature dependence of gaseous products in the co-combustion process of coal slime and cellulose are analyzed by fourier transform infrared spectroscopy and two-dimensional correlation spectroscopy, respectively. This study provides a theoretical basis for the large-scale application of co-combustion of coal slime and biomass.

Biocrusts alleviate the aggravating C limitation in microbial respiration with increasing aridity

Autotrophs (cyanobacteria and mosses) in biocrusts promote soil organic C content and determine soil C dynamics in drylands. However, whether the increased C availability would mitigate microbial C limitation is unknown. The microbial respiration under control without C addition and two forms of C addition (glucose or cellulose) was measured using the topsoil (0–2 cm) and subsoil (2–5 cm) from bare ground lacking biocrusts, cyanobacteria-crusted soil, and moss-crusted soil collected in 36 sites along an aridity gradient in northern China. Microbial C limitation was further qualified as microbial respiration under glucose or cellulose addition divided by that without C addition. Finally, the magnitude of alleviated C limitation by biocrusts and the driving forces were evaluated using the relative effect size via comparing microbial C limitation in biocrusted topsoil and subsoil. Microbial respiration increased significantly under both two types of C addition, and the increase of microbial respiration was consistently stronger in glucose addition than cellulose addition, suggesting the universal microbial C limitation in northern China’s drylands. Further, microbial C limitation was strongest in bare ground, and it was significantly lower in cyanobacteria-crusted topsoil and the lowest in moss-crusted topsoil. More importantly, the magnitude of alleviated microbial C limitation increased with increasing aridity. Structural equation modeling demonstrates that the alleviated microbial C limitation was mediated by the direct effect of Chl a concentration of autotrophs in biocrusts and aridity, as well as their indirect effects via increasing soil organic C content and microbial metabolic quotient and decreasing the ratio of fungi to bacterial PLFAs. Our findings provide strong evidence that biocrusts alleviate the aggravating C limitation in microbial respiration with increasing aridity.

Effect of Alkaline Treatment and Fumigation (Fumigation) on the Mechanical Properties of Fiber Unsaturated Polyester-Cantula Composite with Compression Molding Method

<p>This research examines the strength of the UPRs-Cantula composite with the<br />addition of filler microcrystalline cellulose (MCC). Composites were created<br />with a volume fraction of 30% Vf and a 45° angle. This angle variation received<br />the same treatment as the others, including untreated, alkaline, and fumigation.<br />The treatment time for alkali treatment was 6 hours, while the treatment time<br />for fumigation was 10 hours. The strength of each angle variation was<br />determined, as well as its treatment of tensile strength, modulus of elasticity,<br />and Poisson's ratio UPRs-cantula composites. According to the results, the<br />alkali treatment produced the highest tensile strength and elastic modulus<br />values. The highest Poisson ratio value was discovered without treatment at a<br />45°. The alkaline treatment yielded the highest tensile strength and modulus of<br />elasticity test results. The pullout fiber fracture dominated the untreated<br />composite fracture, whereas the fiber breakage fracture dominated the alkaline<br />treatment.</p>

Pengaruh Penambahan Serat Kulit Kopi dan PVA terhadap Karakteristik Biodegradable Foam dari Pati Kulit Singkong

Polystyrene plastic or stryrofoam is very popular to be used as a food packaging container even though Styrofoam has a bad impact on health. In addition, Styrofoam also cannot be biodegraded naturally in the environment so that the use of Styrofoam is also a problem for the environment. One alternative to styrofoam is biodegradable foam (biofoam) made from starch and cellulose. It is safe for health and can be broken down naturally.Cassava peel is rich in starch (carbohydrates) but has low cellulose content. Meanwhile coffee peel is rich in cellulose and minimal in carbohydrates. Both types of waste have the potential to become biodegradable foam raw materials. The addition of synthetic PVA polymer is expected to improve the mechanical quality of biodegradable foam. This study aims to obtain the best formulation for the manufacture of biodegradable foam from cassava starch with the addition of coffee peel cellulose and PVA. The quality of biofoam evaluated includes tensile strength, water absorption, and biodegradability. The best biofoam characteristics were obtained at the addition of 15% fiber and 15% PVA, resulted in water absorption of 28.87%, tensile strength of 2.70 N / mm2 and biodegradability of 93.66% for 30 days.

Sodium Carboxymethyl Cellulose-Enhanced GCLs in Freshwater Reservoirs

Biopolymers that are environmentally friendly organic products are increasingly used in geotechnical applications instead of synthetic polymers and other chemical additives. Cellulose is a biopolymer that is obtained from the cell walls of plants. In order to evaluate its effect on internal erosion, triaxial permeability tests were performed on a sodium carboxymethyl cellulose-enhanced geosynthetic clay liner (GCL) with Ca bentonite that was placed over a coarse gravel with an average grain diameter of 2.5 cm and permeated with tap water. Furthermore, unconfined compression tests were conducted on the cellulose-added bentonite component of the GCL in order to evaluate the mechanical effect of sodium carboxymethyl cellulose addition to the GCL on internal erosion. Test results indicated that 2% cellulose addition by dry weight maintained sufficient hydraulic and mechanical performances with almost 2.5 orders of magnitude decrease in permeability and 10 times increase in unconfined compressive strength. However, cellulose addition had only a slight enhancement against internal erosion. All the tested GCLs resisted against internal erosion up to a hydraulic head of 25 m. But 30 m hydraulic head resulted in internal erosion for the GCLs enhanced with up to a content of 2% cellulose.

Spherical Eu3+-doped calcium titanate phosphor particle preparation via hydrothermal conversion of hydrous titania

• Spherical Eu 3+ -doped hydrous titania particles achieved via Ti-alkoxide hydrolysis. • Eu 3+ -doped hydrous titania particles were hydrothermally converted to CaTiO 3 :Eu 3+ . • The CaTiO 3 :Eu 3+ particles precisely maintained the starting Eu 3+ ion composition. • The addition of HPC suppressed the formation of the CaTi 2 O 4 (OH) 2 byproduct. Spherical and uniformly sized CaTiO 3 :Eu 3+ phosphor particles were synthesized via the hydrothermal conversion of Eu 3+ -doped hydrous titania particles. 3 mol% Eu 3+ -doped hydrous titania particles with a uniform size and spherical shape were prepared via hydrolysis of Ti-alkoxide. The prepared particles were hydrothermally treated in a Ca(OH) 2 water suspension and converted to CaTiO 3 phosphor particles. The original Eu 3+ -doped hydrous titania particle morphology and composition were precisely maintained. The addition of hydroxypropyl cellulose to the hydrothermal conversion reaction system inhibited the formation of CaTi 2 O 4 (OH) 2 byproducts, as well as the additional deposition of small precipitates in the liquid phase.

Effect of Supplementation of Cryoprotectant Solution with Hydroxypropyl Cellulose for Vitrification of Bovine Oocytes.

Simple SummaryThis study investigated the effects of the addition of hydroxypropyl cellulose (HPC) to a vitrification solution of bovine oocytes. For the vitrification, bovine metaphase II oocytes were pretreated with a solution containing 10% ethylene glycol supplemented with 0, 10, 50, or 100 µg/mL HPC for 5 min, then exposed to a solution containing 30% ethylene glycol supplemented with 0, 10, 50, or 100 µg/mL HPC for 30 sec, and then directly plunged into liquid nitrogen. The survival rate of the oocytes was significantly higher in the 50 HPC group than in the 0, 10, and 100 HPC groups. The reactive oxygen species (ROS) levels of the non-vitrified-thawed (VT) and the 50 HPC groups were significantly lower than the 0, 10, and 100 HPC groups. The mRNA expression levels of the genes related to proapoptotic (Bax) was higher in the 0 and 100 HPC groups than in the 50 and non-VT groups. The mRNA levels of antiapoptotic genes (BCl2) were higher in the non-VT than in the other groups. The development rates of the embryos (day 8) obtained via parthenogenetic activation (PA) were determined in the non-VT, 0 HPC, and 50 HPC groups. The development rate was significantly higher in the non-VT and 50 HPC groups than in the 0 HPC group. Conclusion: Supplementation of vitrification solution with HPC improves the survival of VT bovine oocytes and the development capacity of embryos derived from these oocytes via PA.The technology of successful cryopreservation is a very important factor in research and commercial applications. However, the survival and development of the vitrified-thawed (VT) oocytes are lower than those of non-vitrified-thawed (non-VT) oocytes. This study investigated the effect of the addition of hydroxypropyl cellulose (HPC) to a vitrification solution of bovine oocytes. For the vitrification, bovine metaphase II oocytes were pretreated with a solution containing 10% ethylene glycol supplemented with 0, 10, 50, or 100 µg/mL HPC for 5 min, then exposed to a solution containing 30% ethylene glycol supplemented with 0, 10, 50, or 100 µg/mL HPC for 30 sec, and then directly plunged into liquid nitrogen. Oocytes exposed to 0, 10, 50, and 100 µg/mL HPC were named the 0, 10, 50, and 100 HPC groups, respectively. Samples were thawed via sequential incubation in Dulbecco’s phosphate-buffered saline (D-BPS) supplemented with 10% fetal bovine serum and decreasing concentrations of sucrose (1, 0.5, 0.25, and 0.125 M) for 1 min each time. After thawing, VT oocytes were treated at 0.05% hyaluronidase, and cumulus cells were removed by mechanical pipetting. The oocytes were washed with HEPES-buffered Tyrode’s medium and incubated in a droplet of previously cultured in vitro maturation medium for 1 h to recover. The survival rate of the oocytes was significantly higher in the 50 HPC group (84.2%) than in the 0 (75.4%), 10 (80.4%), and 100 (75.5%) HPC groups. The reactive oxygen species (ROS) levels of the non-VT and 50 HPC groups were lower than the 0, 10, and 100 HPC groups. The mRNA levels of proapoptotic genes (Bax) were lower in the non-VT, 0, and 50 HPC groups than in the other groups. The mRNA expression levels of antiapoptotic genes (BCl2) was higher in the non-VT than in the other groups. The mRNA level of a stress-related gene (Hsp70) was lower in the 50 HPC than in the other groups. At day 8, the developmental capacity of embryos obtained via parthenogenetic activation (PA) was determined in the non-VT, 0 HPC, and 50 HPC groups. The cleavage rate of the non-VT group was significantly higher, but the blastocyst development rate and total cell number per blastocyst did not significantly differ between the non-VT and 50 HPC groups. The mRNA levels of proapoptotic genes (Bax and Caspase-3) and a stress-related gene (Hsp70) were higher in the 0 HPC group than in the non-VT and 50 HPC groups. In conclusion, supplementation of vitrification solution with HPC improves the survival rate of VT bovine oocytes and the development capacity of embryos derived from these oocytes via PA.

In Vitro and In Vivo Scalp Retention and Penetration of 99mTc-Minoxidil Solution

The present study assessed the effect of retention on ex vivo skin and in vivo scalp penetration of radiolabeled minoxidil formulations (5% w/v). Minoxidil was radiolabeled with technetium (99mTc) with an efficiency of 99.1% using 0.2% stannous chloride as reducing agent at pH 6 and incubation temperature of 40 °C. Three different 99mTc-minoxidil formulations were prepared using aqueous ethanolic solution as vehicle. Formulation A contains 99mTc-minoxidil dissolved in vehicle, formulation B contains 10% propylene glycol (PG) and formulation C contains 10% hydroxypropyl cellulose (HPC), in addition. Results showed that addition of HPC resulted in enhanced viscosity (400 mPa.s) and significantly higher ex vivo retention (p < 0.05) and permeation (0.75±0.12%, 8 h). PG does not improve the permeation and the results (0.44±0.05%, 8 h) were not significantly different from vehicle alone (0.40±0.05%, 8 h). The results of the in vivo human scalp studies corroborated with the ex vivo results and addition of hydroxypropyl cellulose (HPH) showed significantly higher (p < 0.05) scalp retention. Post 8 h application, scalp penetration in group treated with formulation C was nearly 2.8-fold and 2.2-fold higher than those treated with formulation A and B, respectively. Further, absence of minoxidil in systemic circulation during study duration indicates safety. In conclusion, our results showed that increasing contact time of minoxidil with scalp by modifying viscosity results in reduced frequency of application and improved efficacy.

Pengaruh Selulosa Nanokristal dari Serat Buah Kelapa Sawit sebagai Pengisi dan Kalium Klorida sebagai Agen Pendispersi Terhadap Sifat Fisik Bioplastik Berbasis Pati Biji Alpukat (Persea americana)

This study aims to determine the effect of nanocrystalline cellulose and potassium chloride (KCl) to bioplastics from avocado seed starch and glycerol as plasticizer. In this study, nanocrystal cellulose obtained from palm fruit fiber was hydrolyzed using sulfuric acid (H2SO4) at a concentration of 50%. The starch used in this study was obtained from the avocado seed extraction process. On producing bioplastic, the casting method was used with the addition of nanocrystal cellulose as filler of 1%, 2%, 3%, and 4% (%w), KCl as dispersing agent of 0%, 1%, 2%, and 3% (%w), and glycerol as plasticizer by 30 (%w). Based on the density test, the optimum value was obtained at 2% of nanocrystal cellulose and 2% of KCl with the value around 0.041 gram/cm3. The best water absorption values were 57.1% and 53.8% which obtained at 2% of nanocrystal cellulose and 1% of KCl. Scanning Electron Microscope test results showed uniformly distributed nanocrystal cellulose granules filling the surface of the bioplastic. The addition of KCl as dispersion agent give a good impact.

Core-shell FeMn@NG derived from cellulose supported Prussian blue analogs for peroxymonosulfate activation: Non-radical mechanism and ultra-low metal leaching

FeMn bimetallic nanoparticles coated with nitrogen-doped graphene shells (FeMn@NG) were prepared by calcination of cellulose supported Prussian blue analogs under N2 flow, and used as catalysts to activate peroxymonosulfate (PMS) for the degradation of 2,4,6-trichlorophenol (2,4,6-TCP). The addition of cellulose during the formation of Prussian blue analogs reduced the agglomeration of metal particles in the subsequent carbonization process, thus increasing the specific surface area and enhancing the catalytic efficiency of the obtained catalyst. 1O2 and the electron transfer pathway were proved to be the main mechanisms by radical quenching experiment, electron paramagnetic resonance and chronoamperometry analysis. The metal leaching of lower than 0.1 mg L−1 and high catalytic stability were attributed to the stable core-shell structure that the metals were encapsulated and protected by graphene shells. The XPS analysis implied that a Fe/Mn redox cycle existed and played a role in balancing electrons during the PMS activation. This study shows that the PMS activator with high catalytic activity can be obtained for the degradation of pollutants by combining Prussian blue analogs with cellulose.

Effect of Additional Cellulose Bacterial from Nata De Soya and Chitosan in Bioplastic Manufacturing

Plastics are synthetic polymers from petroleum or petrochemicals that are difficult to biodegrade by bacteria and microbes. Non-biodegradable plastics cause the accumulation of large amounts of plastic waste Solutions that can reduce plastic waste by making plastics that are easily biodegradable. In this study, tofu liquid waste is used as a basic material for the manufacture of bioplastics. Tofu liquid waste is waste generated from tofu production. This study aims to determine the effect of adding bacterial cellulose and chitosan on the manufacture of bioplastics from liquid waste tofu (whey) in terms of tensile strength, elongation, water solubility, and functional groups (FTIR) in accordance with PET plastic standards (Polyethylene terephthalate). The research procedure on the effect of adding bacterial cellulose and chitosan on the bioplastic fabrication of Nata De Soya. First, from tofu liquid waste, Acetobacter Xylinum starter was added and then fermented for 10-12 days to become Nata De Soya. After that it was neutralized with aquadest, removed the water by pressing, and dried to become bacterial cellulose. The process of making bioplastic with the addition of chitosan (grams) 2,3; 3.1; 3.9; 4.7 and 5.5 and bacterial cellulose (grams) 0.5 ;1.5; 3.9; 7; and 11. In the manufacture of bioplastics with the addition of Bacterial Cellulose and chitosan, it is appropriate, namely the tensile strength obtained will increase and the solubility in water decreases. From the results of our research, the best results were obtained in the addition of S5K5 with a tensile strength value of 9.665 MPa, an elongation value of 31.3%, and a solubility value in water of 17.9%. It has a higher tensile strength, smaller elongation and lower water solubility. The effect of the addition of chitosan on the tensile strength value can increase the tensile strength (Tensile Strength Value), the addition of bacterial bacterial cellulose and chitosan can affect the elongation of bioplastics getting smaller and the effect of chitosan can reduce solubility in water. It is good but still far from the standard PET (Polyethylene Terefelat) which is 60-80 Mpa.

Effect of Nanocrystal Cellulose Isolated from Empty Fruit Bunches (Elaeis Guineensis Jack) Addition on Morphological and Mechanical Properties of Natural Rubber Latex Product.

The research about the effect of the addition of nano crystal cellulose (NCC) isolated from empty palm bunches (EPB) on the morphological and mechanical properties of natural rubber latex products was successfully conducted. This research was carried out in three steps: i.e isolation of α-cellulose from EPB, followed by isolation NCCs from α-cellulose using H2SO4 48.84% at 45ºC for 25 minutes, and manufacture of latex compound with varying filler NCC were 0, 0.6, 1.2, 1.8, 2.4, and 3.0. Manufacturing of natural rubber product was made with pour the NRL followed by vulcanized at 120ºC for 30 minutes. The sheet of NRL product was produced later characterized its mechanical properties through tensile test and surface morphology analysis by SEM. The optimum value of the tensile test result of the NRL product sheet was at the addition of 1,2 phr of NCC with values of tensile test, elongation at break, and Young’s modulus was 3.771 MPa, 877%, and 0.430 Mpa respectively. In addition, surface morphology analysis showed that the NCC was spread evenly.

Porous cellulose-collagen scaffolds for soft tissue regeneration: influence of cellulose derivatives on mechanical properties and compatibility with adipose-derived stem cells

This study compares two types of bioresorptive cellulose, i.e., calcium-sodium salt of oxidized cellulose (OC) and sodium salt of carboxymethylcellulose (CMC). It investigates which type would be preferable as an implant material in terms of biocompatibility, biomechanical and biological properties, and also in terms of its behavior in combination with collagen fibrils (Col) in composite Col/OC or Col/CMC scaffolds. OC significantly supported the stiffness and elasticity of Col fibrils, whereas CMC significantly reduced these properties. OC also enabled a strong interaction with Col fibrils even in a moist environment, accompanied by a significant drop in elastic modulus. The addition of cellulose did not significantly influence scaffold porosity; however, changes in surface morphology and the lower swelling capacity of OC, with a degree of oxidation of its chains between 16 and 24%, supported the idea of improved cell-material interaction. The elasticity and the stiffness of Col/OC guided human adipose-derived stem cells (hADSCs) to significantly higher adhesion, proliferation, and metabolic activity. On the contrary, the Col/CMC provided only limited mechanical support for the cells and inhibited their attachment and proliferation, although without any signs of cytotoxicity. This phenomenon could be used for future control of the differentiation of hADSCs towards a desired phenotype to generate advanced tissue replacements using modern methods of tissue engineering. The oxidation of cellulose resulted in a firmer scaffolding material, as required in vascular or skin tissue engineering. CMC is suitable for moist wound healing, e.g. as a mucoadhesive gel, where cell adhesion is not desirable.Graphical abstract

Carbon stock stability in drained peatland after simulated plant carbon addition: Strong dependence on deeper soil

Peatlands are vital soil carbon sinks, yet this function is jeopardized by plant carbon which could change the decomposition rate of soil organic carbon, knowing as “priming effect”. How the priming effect depends on depth is a critical question in drained peatland given the heterogeneity of soil layers defined by the water table, which include the surface acrotelm, inter-mesotelm and deep catotelm. Here, through incubation, we quantified the response of these three soil layers to addition of 13C-labeled oxalate, glucose, cellulose, or cinnamic acid under anoxic or oxic conditions on the Zoige Plateau in Tibet. Soil carbon in the inter-mesotelm showed the greatest decomposition, with the highest humification index and lowest microbial biomass carbon, while the soil carbon at the surface acrotelm was least decomposed. Under anoxic conditions, exogenous carbon addition reduced CO2 emission by 12.2% at the surface acrotelm but increased by 59.8% in the inter-mesotelm and 23.5% in the deep catotelm. In the inter-mesotelm, oxalate addition significantly increased CO2 emission by 63.9%, while cinnamic acid significantly increased it by 92.9%. In the deep catotelm, cinnamic acid significantly increased CO2 emission by 55.3%. These results suggested that deeper soil organic carbon was more sensitive to plant carbon, particularly complex or recalcitrant carbon, than surface acrotelm soil. Under oxic conditions, carbon addition increased surface soil CO2 emission by 18.9%, and triggered even greater increase at inter-mesotelm and deep catotelm soil, with proportions of 48.3% and 32.0%, respectively. Under both conditions, peat profile CO2 release increased by 17.2–31.4% after exogenous carbon addition, and more than 77.8% of the increase came from the deeper two layers. These findings highlighted the need to take full account of priming effect of deeper soil in order to assess and predict the stability of carbon stocks in drained peatland.

Optimization of Biocomposite Film Based on Whey Protein Isolate and Nanocrystalline Cellulose from Pineapple Crown Leaf Using Response Surface Methodology.

This study employed response surface methodology to optimize the preparation of biocomposites based on whey protein isolate, glycerol, and nanocrystalline cellulose from pineapple crown leaf. The effects of different concentrations of nanocrystalline cellulose as a filler and glycerol as a plasticizer on the thickness, the tensile strength, and the elongation at break on the resulting biocomposite films were investigated. The central composite design was used to determine the optimum preparation conditions for biocomposite films with optimum properties. The regression of a second-order polynomial model resulted in an optimum composition consisting of 4% glycerol and 3.5% nanocrystalline cellulose concentrations, which showed a desirability of 92.7%. The prediction of the regression model was validated by characterizing the biocomposite film prepared based on the optimum composition, at which the thickness, tensile strength, and elongation at break of the biocomposite film were 0.13 mm, 7.16 MPa, and 39.10%, respectively. This optimum composition can be obtained in range concentrations of glycerol (4–8%) and nanocrystalline cellulose (3–7%). Scanning electron microscope images showed that nanocrystalline cellulose dispersed well in the pure whey protein isolate, and the films had a relatively smooth surface. In comparison, a rough and uneven surface results in more porous biocomposite films. Fourier transform infrared spectroscopy revealed that nanocrystalline cellulose and glycerol showed good compatibility with WPI film by forming hydrogen bonds. The addition of nanocrystalline cellulose as a filler also decreased the transparency, solubility, and water vapor permeability and increased the crystallinity index of the resulting biocomposite film.

Green nanocomposite made from carboxymethyl cellulose reinforced with four types of cellulose nanomaterials of wheat straw

AbstractIn this study, four types of cellulose nanomaterials obtained from wheat straw including cellulose nanocrystals (CNCs), TEMPO oxidized cellulose nanofibers (TCNFs), mechanical‐driven cellulose nanofibers (MCNFs) and lignocellulose nanofibers (LCNFs) were first produced and then separately added to carboxymethyl cellulose (CMC) with different mixing ratio of 1, 3, and 6 wt% to make nanocomposite. Pure CMC film and cellulose microfibers (CFs) reinforced composite were also fabricated. BET test showed that TCNFs and CFs had the highest (124 m2/g) and lowest (3.6 m2/g) specific surface area, respectively. FE‐SEM confirmed that TCNFs and CFs presented the thinnest (8 ± 4 nm) and the thickest (24 ± 7 μm) fibers. The nanocomposite containing TCNFs had a transparency of 56%, while CF‐CMC composite showed the lowest one (18%). After the addition of cellulose nanomaterials the XRD peaks of nanocomposites became narrower and shifted partly to the right side compared to that of pure CMC. The highest and lowest water vapor permeability values obtained for rod‐like CNC reinforced nanocomposite and pure CMC film, respectively. The nanocomposite containing 6 wt% TCNFs showed the highest tensile strength and Young's modulus. Cellulose nanomaterials positively affected on the strain at break of the nanocomposites.

A novel experimental approach to quantitatively evaluate the printability of inks in 3D printing using two criteria

Material extrusion enables deposition of filaments with designed structures, and such sub-categories as direct ink writing brings increasing possibilities for the fabrication of multi-material and complex-shaped high-performance fully dense components. It has been well understood that the critical requirement for successful direct ink writing is the printability of inks. To address this challenge, a novel experimental approach that takes advantages of the developed rotational rheology test and capillary rheology test, has been proposed to evaluate the printability of inks that were prepared from the water-based slurries of Al 2 O 3 , Y 2 O 3 and Nd 2 O 3 ceramic powders according to the stoichiometry ratio of Y 3 Al 5 O 12 /Y 2.982 Nd 0.018 Al 5 O 12 with different additions of hydroxyethyl cellulose. The parameters including the low strain value (0.4%) within the linear viscoelastic region and the high shear rate (85 s -1 ) of the inks have been determined by the amplitude sweep test and theoretical analysis. Two criteria - storage modulus and extrusion stress - have been first introduced to assess the success of inks applicable in direct ink writing. Using these criteria, the excellent qualities of printable inks have been quantitatively defined with the values in the range of 2300–6000 Pa and 401–430 Pa, respectively. Moreover, results of capillary extrusion experiments have provided a useful insight into the technology development of suppressing the appearance of bubbles. Finally, the correctness of the proposed approach has been further examined by another transparent ceramic ink, and the in-line transmittance (84.4%) of the transparent ceramic at 1064 nm that is close to the theoretical value has been observed.