Ammonium Zirconium Carbonate Research Articles

Lignin-Containing Coatings for Packaging Materials-Pilot Trials.

One severe weakness of most biopolymers, in terms of their use as packaging materials, is their relatively high solubility in water. The addition of kraft lignin to starch coating formulations has been shown to reduce the water solubility of starch in dry coatings. However, lignin may also migrate into aqueous solutions. For this paper, kraft lignin isolated using the LignoBoost process was used in order to examine the effect of pH level on the solubility of lignin with and without ammonium zirconium carbonate (AZC). Machine-glazed (MG) paper was coated in a pilot coating machine, with the moving substrate at high speed, and laboratory-coated samples were used as a reference when measuring defects (number of pinholes). Kraft lignin became soluble in water at lower pH levels when starch was added to the solution, due to the interactions between starch and lignin. This made it possible to lower the pH of the coating solutions, resulting in increased water stability of the dry samples; that is, the migration of lignin to the model liquids decreased when the pH of the coating solutions was reduced. No significant difference was observed in the water vapor transmission rate (WVTR) between high and low pH for the pilot-coated samples. The addition of AZC to the formulation reduced the migration of lignin from the coatings to the model liquids and led to an increase in the water contact angle, but also increased the number of pinholes in the pilot-coated samples.

PEFC Cathode Catalysts of ZrO2/C Prepared By RF Magnetron Sputtering and Crosslinked Polymer Methods

Fuel cells are expected to be clean power generation devices in the future energy society. Various types of fuel cells, which are different in electrocatalysts, electrolytes, and operating temperatures, are available for practical use in various places depending on their characteristic. Among them polymer electrolyte fuel cells (PEFC) have been applied to fuel cell vehicles (FCV), household cogeneration systems and etc. PEFC uses large amounts of Pt for electrocatalysts, which is one of the serious problems for large scale commercialization. The worldwide production of Pt is about 180 ton/year, and about 60 g of platinum is practically used in one FCV. If all of the world production of Pt is used for FCV, only 3 million of FCV can be manufactured in a year, although the annual production of cars in the world is about 100 million. Therefore, the development of electrocatalysts with non-Pt materials is indispensable for the broad spread of PEFC. The cathode catalysts significantly affect to the cell voltage, current density, and durability, so that the developments of alternative cathode materials to conventional Pt-based catalysts are expected. Compounds of oxides of group 4 and 5 elements transition metals such as Zr, Ta, Nb, and Ti, chalcogenides such as Ru and Mo, and carbon materials with N-containing complexes of Fe and Co, carbon materials doped with B and N are intensively investigated in the past decade. In this study, ZrO2/C catalysts were investigated for oxygen reduction reaction (ORR) activity in acidic media. Two types of preparation methods have been examined; radio-frequency magnetron sputtering and crosslinked polymer methods.In magnetron sputtering method, carbon black (CB) powders were stirred in a rotary drum chamber with milling balls and cubes. A Zr metal target was attached to a sputtering gun placed in the stirring drum. Sputtering was performed in 10 Pa of Ar. In crosslinked polymer method, ammonium zirconium carbonate (AZC) was used as a crosslink reagent for polyvinyl alcohol (PVA). Addition of citric acid (CA) was found to be effective. Mixture of AZC, PVA, and CA were well stirred at 80ºC, and CB was immersed in the mixture. The mixture was dried at 300ºC in air and them heat treated 600~1200ºC in N2 or H2. The catalyst ink was obtained by ultrasonically dispersing 300 µL of isopropanol (IPA), 4 mg of catalyst and 12 µL of 5% Nafion-dispersed solution. The sample electrode was prepared by dropping 150 µL of the catalyst ink on glassy carbon (GC) and drying. ORR activity was measured in 0.1 M H2SO4 with O2 bubbling.ORR activity of ZrO2/C catalysts which were prepared by sputtering method was shown in the attached figure. This figure shows ORR properties of ZrO2/C catalysts prepared at various sputtering times in 0.1 M H2SO4. ZrO2/C was pretreated in H2 flow at 1000˚C for 3 h. ORR current was difference between current in O2 and N2 saturated solutions. ORR Current appeared around 0.8 VR HE for the catalysts deposited longer than 40 min. This result indicate ZrO2/C have obvious ORR activity. X ray diffraction (XRD) of ZrO2/C showed the formation of both monoclinic and tetragonal ZrO2 crystals. ZrO2 particles with diameter in several nm scale were observed by transmission electron microscopic (TEM) images, and formation of these particles were concluded to contribute the obvious ORR activity. On the other hand, ZrO2/C catalysts which were prepared by crosslinked polymer methods also showed similar ORR activity to those by sputtering method. The details were discussed in the presentation.This work was supported by ESICB, Kyoto University and New Energy and Industrial Technology Development Organization (NEDO) of Japan. Figure 1

Machine Learning assisted design of tailor‐made nanocellulose films: A combination of experimental and computational studies

Nowadays, modern nanomaterial research is complemented by machine learning methods to reduce experimental costs and process time. With this motivation, here, we implemented artificial neural network (ANN), random forest (RF), and multiple linear regression (MLR) methods to predict the mechanical properties of three‐component nanocomposite films consisting of polyvinyl alcohol (PVA) crosslinked 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) oxidized cellulose nanofibers (TOCNFs) and either ammonium zirconium carbonate (AZC) or glyoxal (Gx) using the mechanical properties of mono‐component TOCNF films and two‐component nanocomposites containing PVA, AZC, or Gx‐crosslinked TOCNF as the input of prediction system. Prediction methods were evaluated with performance indicators and experimental data. Overall, MLR performed with least accuracy, whereas ANN prediction displayed the lowest error followed closely by RF. Additionally, the physically or/and chemically crosslinked hybrid films with optimized amount of crosslinkers resulted in structures with a strength to rupture that was significantly higher than that of the pure nanocellulose films (increases of up to ~90% in tensile strength and ~70% in Young's modulus). POLYM. COMPOS., 40:4013–4022, 2019. © 2019 Society of Plastics Engineers

Glyoxal improved functionalization of starch with AZC enhances the hydrophobicity, strength and UV blocking capacities of co-crosslinked polymer

An effective and facile approach to functionalize starch was developed using glyoxal and ammonium zirconium carbonate (AZC) as the co-crosslinking agents. The resultant starch was characterized for chemical structure, surface morphology, thermal stability, optical and hydrophobic properties and mechanical strength. 1H and 13C nuclear magnetic resonance (NMR) spectrum confirmed the successful Schiff-base reaction on the starch. X-ray diffraction (XRD) showed that the low glyoxal dosage had an adverse impact on the degree of crystallinity. Thermalgravimetric (TG) results revealed the weakened thermal stability at the initial decomposition process and enhanced thermal stability above the maximum degradation temperature. A smoother surface on the resultant film was observed by scanning electron microscopy (SEM) after the addition of glyoxal. Significantly, enhanced mechanical and hydrophobic properties as well as ultraviolet (UV) blocking capacity of the resultant starch film were achieved at 5% (wt) glyoxal and 5% (wt) AZC content. Improved hydrophobic property and mechanical strength were also obtained even with very low dosages of glyoxal (0.5%, wt) and AZC (2.5%, wt). This new type of starch with double functionalities (i.e., hydrophobic and UV blocking capacity) provides beneficial implications for improving the performance of starch-based materials.

Lignin-containing coatings for packaging materials

Abstract The mechanical properties and chemical stability in water of self-supporting films made from aqueous solutions of starch and lignin, and the barrier properties of paperboard coated with solutions of these polymers have been studied. The dissolution of starch from the starch-lignin films in contact with the model liquids was decreased significantly when lignin was added to the starch films. The addition of ammonium zirconium carbonate (AZC) to the formulations as a crosslinking agent substantially increased the storage modulus of the starch-lignin films, which indicated that crosslinking had occurred. The addition of AZC to the formulations also led to a decrease in dissolution of both starch and lignin from the starch-lignin films in contact with model liquids. The effect of AZC on the water stability of the films was greater when the pH of the starch-lignin-AZC solution was adjusted with ammonia rather than NaOH. The addition of NH4Cl solution as a presumed catalyst to the recipe when the pH adjustment was performed with NaOH did not improve the effect of AZC on the water stability of the films. The water vapour transmission rate of the coated paperboard decreased slightly when AZC was added to the coating formulation.

Films based on crosslinked TEMPO-oxidized cellulose and predictive analysis via machine learning

We systematically investigated the effect of film-forming polyvinyl alcohol and crosslinkers, glyoxal and ammonium zirconium carbonate, on the optical and surface properties of films produced from TEMPO-oxidized cellulose nanofibers (TOCNFs). In this regard, UV-light transmittance, surface roughness and wetting behavior of the films were assessed. Optimization was carried out as a function of film composition following the “random forest” machine learning algorithm for regression analysis. As a result, the design of tailor-made TOCNF-based films can be achieved with reduced experimental expenditure. We envision this approach to be useful in facilitating adoption of TOCNF for the design of emerging flexible electronics, and related platforms.

Colloidal Starch and Cellulose Nanocrystals Unite To Improve the Mechanical Properties of Paper: From Enhanced Coatings to Reinforced Nanocomposites

Emerging paper-based technologies encompassing lab-on-a-chip platforms, microfluidics, sensors, actuators, flexible electronics, and energy-storage devices, such as batteries, demand mechanically robust substrates. Current gold standards for paper and paper board reinforcement rely on petroleum-based binders and coatings, such as latex beads cured with melamine formaldehyde and urea formaldehyde resins, which have raised the red flag because of their environmental footprints. Here, we introduce an all-green reinforcing nanocomposite based on the ammonium zirconium carbonate (AZC)-mediated synergistic crosslinking of starch nanoparticles (biolatex) and a newly emerged type of nanocelluloses named anionic hairy cellulose nanocrystals. AZC, an environmentally friendly and cost-effective crosslinker, reacts with the hydroxyl groups of starch and cellulose nanocrystals, while the carboxylic acid groups of hairy nanocelluloses maintain the solution viscosity low, favoring industrial transportation, which may no...

Preparation and Characterization of Kenaf Papers Reinforced with Tapioca Starch: Physicomechanical and Morphological Properties

ABSTRACTThe present study reports the preparation and characterization of kenaf papers that reinforced with tapioca starch by using the ammonium zirconium (IV) carbonate as coupling agent. The examination shows the tearing resistance, tensile strength, and Young’s modulus of the kenaf papers are enhanced with the addition of starch and coupling agent, up to 3% and 1%, respectively. Under the optimum formulation, the degree of coupling reaction is 87%. The Fourier transform infrared and morphological analyses confirm the performance enhancement of kenaf papers is achieved via the formation of chemical bonding between the kenaf fiber and tapioca starch.

Squishy nanotraps: hybrid cellulose nanocrystal-zirconium metallogels for controlled trapping of biomacromolecules

A brick-and-mortar-like ultrasoft nanocomposite metallogel is formed by crosslinking cellulose nanocrystals (CNC) with ammonium zirconium carbonate (AZC) to trap and reconfigure dextran, a model biomacromolecule. The bricks (CNC) reinforce the metallogel, compete with dextran in reacting with AZC, and decouple long-time dextran dynamics from network formation, while the mortar (AZC) imparts bimodality to the dextran diffusion.

Development of carboxymethyl xylan films with functional properties.

The aim of this work was focused on the development of carboxymethyl xylan (CMX) formulations with functional properties to produce edible films. Beechwood Xylan was firstly derivatized into carboxymethyl xylan and thereafter was blended with Agar (Ag), Ammonium zirconium carbonate (AZC) and linoleic acid (La) to produce CMX:Ag, CMX:AZC, CMX:Ag:La films. Mechanical, barrier, optical and thermal properties of the produced films and their antimicrobial activity against food pathogenic bacteria were evaluated. The obtained films were transparent and yellowish. Agar and AZC improved the tensile strength at break of the control CMX film from 4.79 to 27.67 and 20.95MPa respectively, and the CMX:AZC film exhibited the greatest elastic modulus. Barrier properties of the films decreased when any of the components was incorporated into the CMX and all blended films were thermally more stable than control. The CMX:Ag:La film revealed a good antimicrobial activity against B. cereus and S. aureus.

Softwood-based sponge gels

Crosslinking-aided gelation was utilized to prepare hydrogels from softwood polysaccharides, with spruce galactoglucomannans (GGM)—a group of largely unexploited hemicelluloses—as the main component, aiming at conversion into sponge-like aerogels. Cellulose nanofibrils were used for the formation of a reinforcing network, which was further crosslinked together with a GGM matrix by ammonium zirconium carbonate, an inorganic salt that is regarded as safe for use in food packaging. The hydrogels were freeze-dried into stiff, low-density aerogels with 98 % of their volume composed of air-filled pores. When immersed in water, the aerogels absorbed water up to 37 times their initial weight, demonstrating elasticity and repeatable and reversible sponge capacity. The developed concept reassembles the wood polysaccharides in a new way, creating interesting possibilities for utilizing the abundant “green gold,” GGM. The obtained biobased materials could find application potential, for example, in the field of food packaging and could contribute in the reduction of the usage of petroleum-based plastics in the future.

Influence of Ammonium Zirconium Carbonate on Properties of Poly(vinyl alcohol)/Xylan Composite Films

A series of composite films were prepared using poly(vinyl alcohol) (PVA) and xylan as degradable raw materials under the addition of glycerol and ammonium zirconium carbonate (AZC). The influences of AZC on the mechanical properties, water‐resisting properties, thermal stability, solubility (S), and water vapor permeability of PVA/xylan composite films were comparatively discussed. The results showed that AZC had a positive impact on improving the water resistance and mechanical properties of composite films especially for elongation at break (EAB). With increasing the AZC amounts from 0% to 15%, EAB increased rapidly from 18.5% to 218.0%, and the S values decrease from 11.64% to 8.64%. When the AZC amount reached 15%, the tensile strength still performed well (22.10 MPa). The great compatibility of components in composite films was also observed. Moreover, the addition of AZC had great influences on the thermal stability of composite films and the degradation in soil.

A monomeric [Zr(CO3)4](4-) complex in an ammonium zirconium carbonate aqueous solution studied by extended X-ray absorption fine structure, Raman and nuclear magnetic resonance spectroscopy.

The speciation of zirconium complexes in ammonium zirconium carbonate (AZC) solutions should be further studied in order to develop high-performance AZC complexes for use in elaborate industrial materials. Thus, the speciation and the structure of various zirconium species in ammonium zirconium carbonate solutions were investigated over a wide range of total carbonate and ammonium concentrations. By employing extended X-ray absorption fine structure analysis, and Raman and (13)C NMR spectroscopy, it was found that four carbonate ions coordinate bidentately to the zirconium ion. In addition, the exact concentration ranges of carbonate and ammonium in AZC necessary to generate the monomeric zirconium carbonate complex [Zr(CO3)4](4-) were determined.

Poriferan chitin as a template for hydrothermal zirconia deposition

Chitin is a thermostable biopolymer found in various inorganic-organic skeletal structures of numerous invertebrates including sponges (Porifera). The occurrence of chitin within calcium- and silica-based biominerals in organisms living in extreme natural conditions has inspired development of new (extreme biomimetic) synthesis route of chitin-based hybrid materials in vitro. Here, we show for the first time that 3D-α-chitin scaffolds isolated from skeletons of the marine sponge Aplysina aerophoba can be effectively mineralized under hydrothermal conditions (150°C) using ammonium zirconium(IV) carbonate as a precursor of zirconia. Obtained chitin-ZrO2 hybrid materials were characterized by FT-IR, SEM, HRTEM, as well as light and confocal laser microscopy. We suggest that formation of chitin-ZrO2 hybrids occurs due to hydrogen bonds between chitin and ZrO2.

Preparation of a Crosslinking Cassava Starch Adhesive and its Application in Coating Paper

A new starch-based adhesive with high solid content, high binding force, and low viscosity was prepared via hydrolysis of cassava starch with α-amylase using glycerol as a plasticizer and Ammonium Zirconium Carbonate (AZC) as a crosslinker. The adhesive was applied to coated paper as a partial substitute for SBR latex. The effects of α-amylase, glycerol, AZC, and temperature on the starch adhesive and its performance in application were investigated. The prepared crosslinking cassava starch adhesive showed a significant effect when the starch slurry concentration was 50% (w/w), the dosages of glycerol and α-amylase were 15% and 0.075%, respectively, and the enzymolysis starch was crosslinked with 12% AZC at 50 °C. The modified starch improved the paper in terms of surface strength, gloss, whiteness, and smoothness when 20% SBR latex was substituted into the coating formulation. Statistical analysis indicated that the crosslinking temperature and AZC had significant effects on the performance of the paper, while glycerin and α-amylase had little effect on it. Spectral analysis of the product showed that the crosslinking reaction took place between AZC and cassava starch. The average particle size was 528.6 nm. Scanning Electron Microscope (SEM) images of the paper surface were consistent with the other measured surface properties.

Crosslinking with ammonium zirconium carbonate improves the formation and properties of spruce galactoglucomannan films

Spruce (Picea abies) O-acetyl-galactoglucomannans (GGMs), low-value by-products from the forestry industry were upgraded to sustainable film-forming materials by crosslinking with ammonium zirconium carbonate (AZC). The purpose of crosslinking was to enhance the film formation, reduce the need of polyol plasticizers, and decrease the sensitivity of the film properties to moisture. Tensile testing showed that AZC-crosslinked GGM can be used to prepare strong and stiff films, with tensile strength up to 52 MPa and Young’s modulus of 4.7 GPa. Dynamic mechanical analysis, performed as a function of relative humidity (RH), showed that AZC-crosslinked GGM films retained their stiffness at higher RH than the reference films without AZC. Water vapor sorption and permeability analyses were done to further study the effect of moisture on the film properties, and those showed that the effect of sorbitol as a plasticizer depended greatly on RH. The oxygen permeability of the AZC-crosslinked GGM films was in the range of 4–11 [cm3 μm/(m2 day kPa)]. GGM films could offer a bio-based and biodegradable alternative to existing synthetic oxygen barrier materials, on the condition that they are protected from the effects of moisture, e.g., by hydrophobic laminated layers.

Effect of curing temperature on coating structure and corrosion resistance of ammonium zirconium carbonate on galvanized steel surface

The effect of curing temperature on the structure and corrosion resistance of an ammonium zirconium carbonate (AZC) coating on galvanized steel was investigated as an alternative to chromate. The corrosion resistance of the AZC coating was excellent when cured at 80°C, but it decreased with an increase in the curing temperature; it was significantly inferior at curing temperatures over 160°C. Two endothermic events were observed at 115°C and 155°C. The event at 115°C resulted from the elimination of the water molecule coordinated to the zirconium atom, and the event at 155°C resulted from the dehydration condensation of the hydroxide group involved in the bonds between zirconium, i.e., conversion of an ol-bridge to an oxo-bridge. Furthermore, it was observed that the cathode current of the coating plate cured at 160°C or 200°C, whose corrosion resistance was inferior to that at 80°C or 120°C in the salt spray test, increased. It is supposed that the dehydration occurring at 155°C promoted shrinkage of the coating volume, which in turn caused the development of fissures on the coating surface. The fissures on the coating surface reduced the corrosion resistance significantly due to the increase in cathode current, which signifies the reduction of dissolved oxygen at the coating/metal interface.

Extreme Biomimetics: formation of zirconium dioxide nanophase using chitinous scaffolds under hydrothermal conditions.

Chitinous scaffolds isolated from the skeleton of marine sponge Aplysina cauliformis were used as a template for the in vitro formation of zirconium dioxide nanophase from ammonium zirconium(iv) carbonate (AZC) under extreme conditions (150 °C). These novel zirconia-chitin based composites were prepared for the first time using hydrothermal synthesis, and were thoroughly characterized using a plethora of analytical methods. The thermostability of the chitinous 3D matrix makes it ideal for use in the hydrothermal synthesis of monoclinic nanostructured zirconium dioxide from precursors like AZC. These zirconium-chitin composites have a high potential for use in a broad range of applications ranging from synthetic catalysis to biocompatible materials for bone and dental repair. The synthetic methods presented in this work show an attractive route for producing monoclinic zirconium dioxide on a 3D biocompatible scaffold with ease.

Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System

For the purpose of developing liner board for water-resistant corrugated board in the cold chain system, several types of base paper for corrugated board were purchased from the market and 6 different boards were produced in the paperboard mill by applying the chemicals on the base paper. Then, water-moisture resistant performance and physical properties of the boards were compared each other. The liner board which is dried at high temperature with pressure by Condebelt papermaking system(CK paper) showed a superior performance in strength over common liner boards. Strength of the board increased by surface chemical treatment up to 60% of compressive strength and 30% of bursting strength. Starch insolubilization with Ammonium-Zirconium Carbonate(AZC) and surface coating with a surface size and a moisture resistant chemical on CK paper showed the best result. Therefore, this method was recommended to produce the outer liner board for water -resistant corrugated board.

Rheological study of self‐crosslinking and co‐crosslinking of ammonium zirconium carbonate and starch in aqueous solutions

AbstractDifferent from common hydrogel systems formed by a polymer and a crosslinker, a hydrogel consisting of both self‐crosslinkable ammonium zirconium carbonate (AZC) and co‐crosslinkable starch was investigated in this study using rheological measurements. The evolution of viscoelastic properties of AZC solutions and AZC‐starch mixtures was characterized, and the crosslinking kinetics was determined. It was found that for both AZC self‐crosslinking and AZC‐starch co‐crosslinking, the initial bond formation rate and the gel strength exhibited a power law scaling with polymer concentrations. The competition reaction between self‐crosslinking and co‐crosslinking indicates that the gelation kinetics strongly depends on the AZC concentration but less depends on starch concentration. The temperature dependence of crosslinking was described by the Arrhenius plots which demonstrate a good linearity. It was determined that the activation energy of AZC self‐crosslinking was approximately 145–151 kJ/mol, and the activation energy of AZC‐starch co‐crosslinking was 139 kJ/mol. The effect of solution pH on the crosslinking process was also studied. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011