Increase In Basal Spacing Research Articles

Synthesis of 2,4-D/LHD hybrid nanocomposite using different aging times

Different aging times (1, 2, 4, and 18 h) were used to intercalate the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) into the layered double hydroxide (ZnAl-LDH) using the coprecipitation method to form the 2,4-D/LDH hybrid nanocomposite. The XRD and FTIR results demonstrated that the herbicide was introduced into the layered structure of the LDH, forming an organic-inorganic crystalline nanohybrid in very short aging times, such as one h. The herbicide molecules introduced into the LDH-ZnAl produced an increase in basal spacing, a decrease in crystallinity, and changes in the morphology and particle size of the nanohybrid. The release kinetics obeyed the pseudo-second-order model, and the herbicide release mechanism was done via ion exchange. The analysis of the nanohybrids after herbicide release confirmed the insertion of carbonate anions via ion exchange into the lamellar structure of the LDH by decreasing the basal spacing.

Essential oil in bentonite: Effect of organofunctionalization on antibacterial activities

Essential oils are natural molecules with intense bioactivity, mainly antimicrobial activity, and are used in several industries such as health and food. However, the high volatility of the essential oils limits their application. Therefore, the incorporation of essential oils into solid materials is a strategy to maintain their properties. In this study, the incorporation of nerolidol at 5–50% v/v concentrations in raw and organophilic bentonites was investigated. The antibacterial activities of the oil/clay hybrids against Staphylococcus aureus and Escherichia coli were evaluated using the direct contact test. Transmission electron microscopy and X-ray diffractometry patterns confirmed the intercalation of the oil in sodium bentonite, resulting in a 1.26–1.50 nm increase in basal spacing (d), and in cetyltrimethylammonium clay (CTAB-Bent), which showed a d value of 3 nm. Thermogravimetry indicated that the maximum amount of nerolidol incorporated was 41% by mass (1.84 mmol g−1) in the NE50/CTAB-Bent sample, suggesting a good affinity between the species. The Fourier transform infrared spectra were in concordance with the interactions between the oil and OH groups and the organic groups in the raw and organophilic samples, respectively. Transmission electron microscopy suggested that the layered structure of the samples was maintained without the formation of exfoliated phases. The antibacterial of the hybrids revealed 100% inhibition of both bacteria. The promising results associated with the slow release and effective antibacterial action of the oil-clay hybrids indicate that the obtained materials can be used in the manufacture of pharmaceutical, cosmetic, and healthcare products.

Preparation and properties of silane cross-linked polyethylene nanocomposite foams: The effect of silane and nanoclay type and content

In this study, silane grafted and moisture cross-linked low density polyethylene nanocomposite foams were prepared by melt mixing and batch foaming process and the effects of silane content, nanoclay content, foaming agent concentration and clay type (clay modified with vinyltriethoxysilane (VTES) and amino-propyltriethoxysilane on foaming efficiency and foam properties were investigated. The morphology and the efficiency of silane modification of modified clay were characterized by series of tests, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The results of Fourier transform infrared and thermogravimetric analysis showed that the silane modifiers were bonded to the surface of nanoclay through both physical and chemical bonds. According to XRD, these modifiers caused characteristic peak of clay to shift to lower angles, and make an increase in basal spacing. Gel content, density, scanning electron microscopy, compression, creep and rheological tests were used to determine the effect of different parameters on properties of cross-linked polyethylene foams. Results indicated that silane content has the significant effect on stress-strain behavior in compression mode. Compression set and creep deformation were affected by cell size and gel content. Furthermore, the rheological properties including complex viscosity, storage and loss modulus of unformed samples increased with the addition of silane and nanoclay content.

Synthesis, characterization and adsorption behaviors of modified bentonite towards methylene blue

This study aims to evaluate the effect of tow surfactants hexadecyl(trimethyl)azanium;bromide (CTAB) and 1-butyl-3-methylimidazol-3-ium;chloride (BMIMCl) intercalation in bentonite (Bt) on methylene blue dye adsorption.The modified clays were characterized in detail using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA).The XRD analysis showed the increase of basal spacing ranged between ‎‎20.99 Å and 14.19Å for Bt-CTAB and Bt-BMIM respectively. The FTIR is another tool to investigate the presence of organic matter on the clay surface. More specifically, the results showed that the formation of new bands of vibrations (1400 –1500 cm-1 and 2800–2900 cm-1).Then the organoclays were used to the adsorption of methylene blue .In presence of surfactant the maximum adsorption capacities of Bt-CTAB and ‎Bt-BMIM according to the langmuir model were 47.186 mg.g-1 and 42.28 mg.g-1, respectively. According to the results algerian bentonite sample tested in this paper can effectively remove methylene blue from aqueous solutions.‎

Influence of inorganic and organic salts on the hydration mechanism of montmorillonite based on molecular simulation

The molecular dynamics method is used to further reveal, from the molecular point of view, the mechanisms of salt inhibiting the hydration of Na-MMT. The interaction between water molecules, salt molecules, and montmorillonite are calculated by establishing the adsorption models. According to the simulation results, the adsorption conformation, interlayer concentration distribution, self-diffusion coefficient, ion hydration parameters, and other data are compared and analyzed. The simulation results show that the volume and basal spacing increase in a stepwise manner with the increase of water content, and water molecules have different hydration mechanisms. The addition of salt will enhance the hydration properties of compensating cations of montmorillonite and affect the mobility of particles. The addition of inorganic salts mainly reduces the adsorption tightness between water molecules and crystal surfaces, thereby reducing the thickness of water molecules layer, while the organic salts can better inhibit migration by controlling interlayer water molecules. The results of molecular dynamics simulations reveal the microscopic distribution of particles and the influence mechanism when the swelling properties of montmorillonite are modified by chemical reagents.

Synthesis, characterization, and challenges faced during the preparation of zirconium pillared clays

In this study, Zr-pillared montmorillonite clays (Zr-PILCs) were synthesized using two different precursor materials: raw montmorillonite (CM) and sodium ion-saturated montmorillonite (Na-CM) at different Zr/clay ratios (2.5, 5 and 10 mmol/g). To study the effect of Zr concentration and clay pre-treatment with NaCl on pillaring, the modified clay samples were characterized in detail using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy (STEM-EDX). The XRD analysis showed the increase of basal spacing of Zr-PILCs prepared from both precursor materials: from 1.26 to 1.74 nm in the case of CM, and from 1.13 to 1.93 nm for Na-CM. Results from FT-IR revealed new bands ascribed to Zr-O bonds in the range of 400–500 cm −1 in Zr-pillared samples obtained from Na-CM at Zr/clay ratios of 2.5 and 5 mmol/g. The distribution and nature of Zr species in between the silicate layers were studied using STEM-EDX and HAADF imaging. They were found to be separated by a distance of 1.5–3 nm and their thickness lies in the range of 1–2 nm. Pillared clays prepared from pre-treatment with NaCl were more thermally stable at higher temperatures.

Nano BN reinforced cellulose-based tripolymeric hybrid nanocomposites as packaging materials

ABSTRACT Tripolymeric nanocomposites of polyacrylic acid (PAA), polyethylmethacrylate (PEMA), and carboxymethyl cellulose (CMC) are synthesized by emulsifier-free emulsion polymerization technique with nano boron nitride (BN). The exfoliation of BN platelets is achieved due to increase in basal spacing. It is seen that nano BN creates a torturous path with matrix to arrest the penetration of gas. As a result of good dispersion of nano BN, the permeability of materials is reduced by five times. The significant lowering of permeability with combined improvement in tensile strength and thermal stability enable the materials for potential packaging applications.

Intercalation of montmorillonite with dialkylammonium cationic surfactants

Three montmorillonite (Mt) clays with different cation exchange capacity (CEC) were intercalated by a series of dialkyl ammonium cations with carbon numbers (Nc=) 8, 10, 12 and 18 in each alkyl chain. The intercalated clays were characterized by X-ray Diffraction, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy and Transmission Electron Microscopy. The basal spacing of intercalated Mts increased gradually with increasing chain length. Interlayer arrangement of dialkyl surfactant cations in the intercalated clay gallery changed from flat bilayer to paraffinic and reached as high as 3.57 nm for the highest CEC clay intercalated with cations having Nc= 18 in each alkyl chain. For dialkylammonium intercalants, the increase in basal spacing was predominantly guided by the intercalant's structure and organic loading values lacked such direct correlation. Mt with low CEC showed large expansion in the clay interlayer with increasing alkyl chain length even with marginal increment in the organic loading. The highest basal spacing was observed always with the highest CEC clay for every intercalant irrespective of alkyl chain length. The wide expansion of clay gallery for the longest dialkyl intercalant in this series for all clays might be attributed to presence of intercalated surfactant molecules along with physically adsorbed surfactant cations in the clay interlayer. The change in conformations of intercalated dialkyl ammonium intercalants with increasing alkyl chain length was analyzed from FTIR study. With increasing alkyl chain length, methylene symmetric and asymmetric stretching frequency shifted to lower wavenumber for all Mt clays- which indicated greater ordered conformations obtained with increasing alkyl chain length.

Simultaneous Detoxification of Aflatoxin B1, Zearalenone and Deoxynivalenol by Modified Montmorillonites.

Raw Ca-based montmorillonite (MMT) was treated by H2SO4, calcination and organic compounds (hexadecyltrimethyl ammonium bromide (HTAB), cetylpyridinium chloride (CPC) and chitosan (CTS)), respectively. The modified montmorillonites were characterized by different methods and their adsorption performances for three mycotoxins (Aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON)) were evaluated at pH = 2.8 and 8.0, respectively. The results indicate that surfactants (CPC and HTAB) intercalation is the most efficient modification, which obviously improves the adsorption performance of montmorillonite for mycotoxins, with adsorption efficiency of above 90% for AFB1 and ZEA whether under acid or alkaline conditions, due to the increase in basal spacing and the improvement of hydrophobicity. Moreover, the adsorption efficiencies of AFB1 and ZEA over CPC-modified montmorillonite (CPC-AMMT-3) coexisting with vitamin B6 or lysine are still at a high level (all above 94%). All modified montmorillonites, however, have low adsorption efficiency for DON, with somewhat spherical molecular geometry.

Development and characterization of green polyethylene/clay/antimicrobial additive nanocomposites

In this work, nanocomposites were developed and evaluated using high-density bio polyethylene (BPEAD)/Cloisite 20A (3 and 6%)/commercial antimicrobial additive (0,5 and 1%) containing 1% of zinc pyrithione dispersed in vinyl acetate (EVA). The samples were prepared in a single screw extruder using the melt intercalation technique and then by flat extrusion to obtain the films. X-ray diffraction (XRD) showed an increase in basal spacing and exfoliation of the structure of some films. The Fourier Transform Infrared Spectroscopy (FTIR) analysis illustrated the main functional groups for BHDPE and EVA. Thermal analysis indicated that BHDPE degradation did not change with organoclay addition, but crystallinity increased. The mechanical properties showed an increase in the elastic modulus and a decrease in maximum tensile strength. This work contributes to the development and improvement of the natural properties of BHDPE in order to enlarge its applications.

Organobeidellites for Removal of Anti-Inflammatory Drugs from Aqueous Solutions.

Diclofenac (DC) and ibuprofen (IBU) are widely prescribed non-steroidal anti-inflammatory drugs, the consumption of which has rapidly increased in recent years. The biodegradability of pharmaceuticals is negligible and their removal efficiency by wastewater treatment is very low. Therefore, the beidelitte (BEI) as unique nanomaterial was modified by the following different surfactants: cetylpyridinium (CP), benzalkonium (BA) and tetradecyltrimethylammonium (TD) bromides. Organobeidellites were tested as potential nanosorbents for analgesics. The organobeidellites were characterized using X-ray powder diffraction (XRD), Infrared spectroscopy (IR), Thermogravimetry and differential thermal analysis (TG/DTA) and scanning microscopy (SEM). The equilibrium concentrations of analgesics in solution were determined using UV-VIS spectroscopy. The intercalation of surfactants into BEI structure was confirmed both using XRD analysis due to an increase in basal spacing from 1.53 to 2.01 nm for BEI_BA and IR by decreasing in the intensities of bands related to the adsorbed water. SEM proved successful in the uploading of surfactants by a rougher and eroded organobeidellite surface. TG/DTA evaluated the decrease in dehydration/dehydroxylation temperatures due to higher hydrophobicity. The Sorption experiments demonstrated a sufficient sorption ability for IBU (55–86%) and an excellent ability for DC (over 90%). The maximum adsorption capacity was found for BEI_BA-DC (49.02 mg·g−1). The adsorption according to surfactant type follows the order BEI_BA > BEI_TD > BEI_CP.

Saponin-intercalated organoclays for adsorptive removal of β-carotene: Equilibrium, reusability, and phytotoxicity assessment

Acid-activated clays play an essential role in the edible oil refining industry to remove colored pigments and impurities to meet consumer demands and specific purposes. Despite its high bleaching activity, the use of highly corrosive acids in significant quantities for producing the activated clay raises safety and environmental concerns. Herein, we demonstrate an environmentally friendly and low-cost preparation of organoclay-type bleaching earth via aqueous phase intercalation of bentonite with natural surfactant (rarasaponin) under microwave irradiation. The influence of the rarasaponin concentrations on the textural and chemical characteristics of the resultant organoclays was investigated with relevant techniques, including SEM, XRD, FTIR, and N2 sorption. The results revealed that the intercalation of rarasaponin causes a basal spacing increase to 1.50 nm, surface area to 99.5 m2/g, and pore volume to 0.85 cm3/g, while the cation exchange capacity (CEC) value decreased to 19.1 ± 4.4 meq/100 g; where the untreated bentonite has a basal spacing of 1.39 nm, a surface area of 86.8 m2/g, a pore volume of 0.69 cm3/g, and a CEC value of 30.1 ± 3.6 meq/100 g. The RSB-2 organoclay exhibits the best bleaching activity, with ~91% β-carotene removal efficiency achieved in degummed palm oil compared to the untreated bentonite (72% efficiency). The equilibrium behavior of β-carotene adsorption onto RSB-2 organoclay) was best fit with the Redlich–Peterson isotherm model, giving the theoretical maximum sorption capacity (qmax) 78.09 mg g−1, which represents the best-reported values among the investigated samples. A reusability study of the spent bleaching clay demonstrates that the adsorptive removal of β-carotene remained greater than 90% after five consecutive cycles. The spent RSB-2 organoclays also showed no appreciable phytotoxicity toward Arabidopsis seed germination but a slight inhibitory activity on the root development, suggesting environmentally friendly behavior and allowing for the landfill disposal.

Evaluation of Clay Hydration and Swelling Inhibition Using Quaternary Ammonium Dicationic Surfactant with Phenyl Linker.

Water-based drilling fluids are extensively used for drilling oil and gas wells. However, water-based muds cause clay swelling, which severely affects the stability of wellbore. Due to two adsorption positions, it is expected that cationic gemini surfactants can reduce the clay swelling. In this work, quaternary ammonium dicationic gemini surfactants containing phenyl linkers and different counterions (Cl− and Br−) were synthesized, and the effect of variation in counterions on swelling and hydration properties of shales was studied. Numerous water-based drilling fluid formulations were prepared with different concentrations of surfactants to study the swelling inhibition capacity of surfactants. The performance of surfactant-containing drilling muds was evaluated by comparing them with base drilling mud, and sodium silicate drilling mud. Various experimental techniques were employed to study drilling mud characteristics such as rheology and filtration. The inhibition properties of drilling mud formulations were determined by linear swelling experiment, capillary suction time test, particle size distribution measurement, wettability measurements, and X-ray Diffraction (XRD). Experimental results showed that surfactant-based formulation containing bromide counterion exhibited superior rheological properties as compared to other investigated formulations. The filtration test showed that the gemini surfactant with chloride counterion had higher filtrate loss compared to all other formulations. The bentonite swelling was significantly reduced with increasing the concentration of dicationic surfactants as inhibitors, and maximum reduction in the linear swelling rate was observed by using a formulation containing surfactant with chloride counterion. The lowest capillary suction timer (CST) was obtained in the formulation containing surfactant with chloride counterion as less CST indicated the enhanced inhibition capacity. The particle size measurement showed that average bentonite particle size increased upon the addition of surfactants depicting the inhibition capacity. The increase in basal spacing obtained from XRD analysis showed the intercalation of gemini surfactants in interlayers of bentonite. The contact angle measurements were performed to study the wettability of the bentonite film surface, and the results showed that hydrophobicity increased by incorporating the surfactants to the drilling fluid.

Short-Chain Polyglycerol Production via Microwave-Assisted Solventless Glycerol Polymerization Process Over Lioh-Modified Aluminium Pillared Clay Catalyst: Parametric Study

In the current study, microwave-assisted glycerol polymerization for short-chain polyglycerol production was conducted unprecedentedly over low-cost catalyst, lithium-modified aluminium pillared clay (Li/AlPC) catalysts without the solvent. The influences of disparate reaction parameters such as the effects of Li loadings (10, 20, 30 wt.%), catalyst loadings (2, 3, 4 wt.%), operating temperatures (200, 220, 240 °C) and operating times (1–4 h) on the glycerol conversions, and polyglycerol yield (particularly for diglycerol and triglycerol), were elucidated. The fresh catalysts were subjected to physicochemical properties evaluation via characterization techniques, viz. N2 physisorption, XRD, SEM, NH3-TPD and CO2-TPD. In comparison, 20 wt.% Li/AlPC demonstrated the best performance under non-conventional heating, credited to its outstanding textural properties (an increase of basal spacing to 21 Ȧ, high surface area of 95.48 m2/g, total basicity of 34.48 mmol/g and average pore diameter of 19.21 nm). Within the studied ranges, the highest glycerol conversion (98.85%) and polyglycerol yield (90.46%) were achieved when catalyst loading of 3 wt.%, reaction temperature of 220 °C and reaction time of 3 h were adopted. The results obtained also anticipated the higher energy efficiency of microwave-assisted polymerization than conventional technique (>8 h), as the reaction time for the former technology was shorter to attain the highest product yield. The study performed could potentially conduce the wise utilization of surplus glycerol generated from the biodiesel industry.

Layered Silicate-Alginate Composite Particles for the pH-Mediated Release of Theophylline.

Numerous natural and synthetic clay minerals have proven to be excellent drug carriers for high drug-loaded and sustained release formulations due to their considerable ion exchange, adsorption, and swelling capacities. Moreover, the synthetic smectite clays have added advantages in terms of compositional purity and controlled cation exchange capacity in comparison to natural clays. This study involves the intercalation of theophylline (TP) in a synthetic clay, Laponite® (LP), followed by the inclusion of the resulting intercalates into sodium alginate (SA) beads to achieve pH-controlled drug release. Maximum intercalated drug incorporation of 68 mg/g was obtained by ion exchange at pH 1.2 and confirmed by an increase in basal spacing of the clay from 12.9 to 15.5 Å. TP release from the binary LP-TP intercalates in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was found to be 40% and 70%, respectively. LP-TP particles were also incorporated in an SA matrix via polymer crosslinking using CaCl2(aq) to improve the pH selective release. The ternary polymer-clay-drug composite particles effectively prevented the release of TP at low pH in SGF and resulted in sustained release in SIF, with 40% dissolution within 120 min.

Variasi Jarak Antar Layer Bentonit Pada Pembuatan Nanokomposit Pla-Bentonit Sebagai Kemasan Makanan

In this study, bentonite was used as a filler in the synthesis of polylactic acid (PLA) nanocomposite. The mechanical property of PLA-Bentonite nanocomposite was treated using two different surfactants, namely octadecyl amine (ODA) and trimethyl stearyl ammonium chloride (TSC) at two different concentration (20 mmol and 40 mmol). The treatments of ODA and TSC in the matrix with regards to the basal spacing of bentonite stacks measured by X-Ray Diffraction (XRD) analysis. The results showed a significant increase in basal spacing was obtained when TSC 40 was applied for treatment. Data of Fourier Transform Infrared Spectroscopy (FTIR) suggested that this increase was caused by the incorporation of surfactant into the bentonite stacks. Most of the PLA-Bentonite nanocomposite can form intercalation structure, while a sample containing TSC 40 formed exfoliation structure. This exfoliation structure resulted in a film with the best tensile strength and water vapor permeability compared to the others. The film containing TSC 40 showed the lowest reduction in water activity, almost similar to the bread sample wrapped using conventional plastic. The bread wrapped with TSC 40 film was not grown by fungi as opposed to the conventional plastic, showing the potential of the nanocomposite film as food packaging.

Theoretical and experimental investigation on the intercalation of metformin into layered clay minerals

This work introduces a comparative study on the use of two layered clays, a natural Wyoming montmorillonite (commercialized as Cloisite®Na; Mt) and a synthetic hectorite (commercialized as Laponite® XLG; Lap), to encapsulate metformin (MF), which is the most widely used oral drug for the treatment of type II diabetes. The aim was the evaluation of the suitability of the synthetic Lap clay as substrate for the controlled release of MF in comparison to the montmorillonite clay previously studied, in view to dispose of a convenient and well-regulated clay-based component for pharmaceutical formulation production. The combination of molecular modeling and experimental characterization techniques, such as FTIR, XRD, CHN chemical analysis and EDX, allowed us to study the adsorption process and the final molecular arrangement of MF in the interlayer space of the two silicates. The intercalation of MF in both clays follows an ion-exchange mechanism that leads to a basal spacing increase of 0.36 nm and 0.40 nm for the Lap-MF and Mt-MF systems, respectively, and the intercalated amount of MF matches the cation exchange capacity of each clay. Calculations at molecular level showed thermodynamically favorable systems produced by cation exchange reaction, where the MF species form a monolayer in the interlayer of both clays. In view to the application of these materials as delivery systems of MF, the release of the drug from Lap-MF and Mt-MF intercalation compounds was evaluated in pH conditions that simulate those of the gastrointestinal tract. Interestingly, Lap-MF allows a complete release of the loaded drug, guaranteeing the possibility of reaching an efficient drug delivery system. However, the large MF release in acid medium in both systems makes necessary a further encapsulation of the intercalation compound in a protective polymer matrix to increase the delivery in the intestine. Promising results were obtained using pectin as encapsulating matrix, leading to a gradual release of MF in the simulated gastrointestinal tract conditions.

Synthesis, Characterization, and Applications of Silk/Bentonite Clay Composite for Heavy Metal Removal From Aqueous Solution.

Bentonite clay is an abundant and low-cost adsorbent and silk fibroin, a naturally occurring protein, and both have a low capacity to remove lethal heavy metal ions from aqueous solution separately. To enhance their metal adsorbing capacity, a new silk fibroin-based bentonite composite was prepared for improving water quality by eliminating heavy metal ions i.e., lead, cadmium, mercury, and chromium. The as-synthesized composite shows better metal sorption capacity than either of them alone. To analyze their structural properties and characteristic functional groups, X-ray diffraction and Fourier-transform infrared spectroscopy were used. The specific surface area for silk/bentonite composite was about 4 m2/g that is smaller than the unmodified bentonite (23 m2/g) which indicates the impregnation of bentonite onto the silk fibroins. Scanning electron microscopy results shows the changes in morphology from plate aggregates to rosette like arrangements. The XRD results of clay/composite shows an increase in basal spacing (d001, from 1.55 to 3.34 nm) in comparison to pristine clay. FTIR results show the presence of organic moiety in SF clay composite. The mechanism of adsorption based on complex formation and ion exchange were proposed briefly. Various adsorption isotherms and kinetic models were applied for the removal of Pb(II), Cd(II), Hg(II), and Cr(VI). As the kinetic study was concerned, kinetic data fitted well to pseudo second order kinetics because experimental values of qe are much closer to the calculated values. The adsorption equilibrium was best studied by Langmuir isotherm whose regression coefficient values (0.985–0.995) are best when compared to Freundlich adsorption isotherm (0.954–0.990) and are indicative of homogeneity of adsorption sites on the SF/clay composite. The monolayer adsorption capacity for Cd(II), Pb(II), Hg(II), and Cr(VI) was found to be 11.35, 11.1, 10.5, and 10.2 mg/g, respectively.

Understanding Urea Encapsulation in Different Clay Minerals as a Possible System for Ruminant Nutrition.

Considering the challenges of urea administration due to the high ureolytic activity of the rumen and the importance of its use, as well as taking into account the relevance of sustainably exploiting the technological potential of biodiversity, this research studies the encapsulation of urea in different clay minerals (palygorskite (Pal), sepiolite (Sep), and Veegum® (V)) as an alternative for use as nonprotein nitrogen (NNP) sources. A method of incorporation was developed in which the encapsulation of urea was proven by X-ray diffraction; fibrous materials, Pal and Sep had similar characteristics due to the decrease in the relative plane intensity (011), suggesting a decrease in the order of their stacking due to the presence of urea on the surface or inside channels. By contrast, V showed a 7.74° reflection shift, suggesting an increase in basal spacing from 11.45 Å in V to 14.88 Å in the sample after urea encapsulation. By thermogravimetry, it was observed that the presence of urea did not change the mass-loss profiles but only increased the percentage of loss in respective events, indicating urea incorporation in the clay minerals. These results provide a promising alternative for administering NNP sources in the ruminant diet.

Formulation of Polyurethane with Bentonite-Chitosan as Filler Applied to Carbon Steel as an Antibacterial and Environmentally Friendly Paint

The coating material used for the manufacture of polyurethane paint with the addition of bentonite into the matrix can improve thermal capability. The purpose of this study is to produce new material namely hybrid bentonite-chitosan which can be used as a filler for the manufacture of polyurethane paint, chitosan intercalation process into bentonite interlayer and increase the concentration of surfactant against the opening of bentonite interlayer. By varying the CEC of cationic surfactants (0.7 CEC, 1 CEC, and 1.3 CEC) and CEC anionic surfactants (0.1 CEC, 0.2 CEC and 0.3 CEC) to obtain the highest basal spacing, structure, and morphology, several characterization procedures have been carried out. From the results of interlayer bentonite analysis with modification of cationic and anionic surfactants using XRD (X-Ray Diffraction) an increase in basal spacing from 14.18393 Å to 23,00023 Å. While the FTIR (Fourier Transform Infrared) chemical structure of hybrid bentonite-chitosan at a wavelength of2800 cm-1 shows the C-H group, 1025 cm-1 shows the C-O group and polyurethane in the -OH absorption (3445 cm-1 ). This study can produce hybrid bentonite-chitosan material as a filler in the manufacture of polyurethane paint.