Formation of a Polymer-Coated Inclusion Complex of D-Limonene and β-Cyclodextrin by Spray Drying

The polymer-coated inclusion complex powder formation of D-limonene and β-cyclodextrin obtained by spray drying was investigated with respect to the effects of various types of polymer coating agents on the powder particle size and morphology. The addition of the polymer coating agent affected the average particle size, morphology, and internal structures of the spray-dried powders. The average particle diameter of the uncoated spray-dried powders was approximately 5 µm. The powder particle size increased upon the addition of a polymer coating reagent. With the addition of 9 wt% of the polymer coating agent, an average diameter of approximately 80 µm was obtained for the spray-dried powder particles. However, further addition showed a negligible effect on the particle size. Inclusion complex crystals were observed on the surface and inside of the powder particles.     

Preparation and Characterization of Silica-Coated Magnetic–Fluorescent Bifunctional Microspheres

Bifunctional magnetic–fluorescent composite nanoparticles (MPQDs) with Fe₃O₄ MPs and Mn:ZnS/ZnS core–shell quantum dots (QDs) encapsulated in silica spheres were synthesized through reverse microemulsion method and characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, vibration sample magnetometer, and photoluminescence (PL) spectra. Our strategy could offer the following features: (1) the formation of Mn:ZnS/ZnS core/shell QDs resulted in enhancement of the PL intensity with respect to that of bare Mn:ZnS nanocrystals due to the effective elimination of the surface defects; (2) the magnetic nanoparticles were coated with silica, in order to reduce any detrimental effects on the QD PL by the magnetic cores; and (3) both Fe₃O₄ MPs and Mn:ZnS/ZnS core–shell QDs were encapsulated in silica spheres, and the obtained MPQDs became water soluble. The experimental conditions for the silica coating on the surface of Fe₃O₄ nanoparticles, such as the ratio of water to surfactant (R), the amount of ammonia, and the amount of tetraethoxysilane, on the photoluminescence properties of MPQDs were studied. It was found that the silica coating on the surface of Fe₃O₄ could effectively suppress the interaction between the Fe₃O₄ and the QDs under the most optimal parameters, and the emission intensity of MPQDs showed a maximum. The bifunctional MPQDs prepared under the most optimal parameters have a typical diameter of 35 nm and a saturation magnetization of 4.35 emu/g at room temperature and exhibit strong photoluminescence intensity.     

Inclusion Complex of Sea Buckthorn Fruit Oil with β-Cyclodextrin: Preparation Characterization and Antioxidant Activity

This study aims to produce an inclusion complex between β-cyclodextrin (β-CD) and sea buckthorn fruit oil (SBFO) by using the saturated aqueous solution method and then to compare the resultant solution with the crude mixtures. In this study, the SBFO is extracted by Soxhlet extraction, which is optimized through the single-factor test. The main constituent of the SBFO is identified by gas chromatography-mass spectrometry (GC-MS), which confirms eight fatty acids. Fourier transform infrared spectroscopy, thermogravimetric analysis-differential scanning calorimetry, optical microscopy, scanning electron microscopy, and the result-characterized synthesized compounds confirm the formation of stable inclusion compounds by the SBFO with β-CD. The yield values of the inclusion complex and the SBFO loading content are 64.87 ± 2.26% and 9.2 ± 1.58%, respectively. Comparing the crude fruit oil, β-CD–SBFO, and saponified fruit oil reveals differences in their 2,2-diphenyl-1-pycrylhydrazyl and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) antioxidant activities. These findings suggest that the SBFO inclusion complex after β-cyclodextrin is stabilized and is a good antioxidant. This solution improves the inadequacy of the water solution and the instability of the SBFO. This study also implies that β-CD is a cost-effective and straightforward carrier for extending the applications of SBFO as a food or medicinal additive. Practical applications: In this experiment, the SBFO is converted from oil to powder to increase its efficacy as an additive to health and food products.     

Preparation and Physicochemical Characterization of New Nanocomposites Based on β-Type Chitosan and Nano-Hydroxyapatite as Potential Bone Substitute Materials

In the present study, β-type chitosan [ß (1–4) N-acetyl D-glucosamine] was obtained through a modified procedure from squid pens (Loligo Vulgaris) and characterized to determine its average molecular weight and degree of N-deacetylation. Then, the β-chitosan was used for the first time, in a combination with different proportions of nano-hydroxyapatite (n-HA), to develop new series of nanocomposites as potential bone substitute materials that are able to overcome the poor physicochemical and mechanical properties of pure artificial hydroxyapatite. The β-chitosan/n-HA nanocomposites were prepared through in situ coprecipitation technique and characterized with the aid of FTIR, XRD, and EDS. Surface morphology of the nanocomposites was examined using SEM and TEM. The mechanical properties were also studied through measuring the compressive strength of the developed composites.     

Synthesis and Characterization of the Inclusion Complex of Dicationic Ionic Liquid and β-Cyclodextrin

The supramolecular structure of the inclusion complex of β-cyclodextrin (β-CD) with 1,1',2,2'-tetramethyl-3,3'-(p-phenylenedimethylene) diimidazolium dibromide (TetraPhimBr), a dicationic ionic liquid, has been investigated. The inclusion complex with 1:1 molar ratio was prepared by a kneading method. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) analysis, (1)H NMR and thermogravimetric analysis (TGA) confirmed the formation of the inclusion complex. The results showed that the host-guest system is a fine crystalline powder. The decomposition temperature of the inclusion complex is lower than that of its parent molecules, TetraPhimBr and β-CD individually.     

Preparation and Characterization of Silicone Rubber Membrane

Pervaporation membrane with preferential permeation for organic compounds over water was prepared and characterized. Selection of membrane material and the effects of polydimethylsiloxane (PDMS), cross-linker, and catalyst concentrations on performances of pervaporation membrane at room temperature were discussed. In addition, the time of cross-linking, and the kinds of basic plate in the process of preparation were tested. The formulation of pervaporation membrane material was determined. Through the characterization of membrane by infrared spectrometry(IR), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD), it is proved that the structures and characters are suitable for the pervaporation process. Experiments also demonstrate that the permeate flux and separation factor are suitable for the process.     

Microencapsulation of α-Amylase by Carrying Out Complex Coacervation and Drying in a Single Step Using a Novel Three-Fluid Nozzle Spray Drying

The aim of this research was to develop an enzyme encapsulation process in which both the complex coacervation and drying processes are combined into a single step. For this purpose, we used a novel three-fluid nozzle at the atomization step of spray drying. α-Amylase as a model enzyme was encapsulated by coacervation in calcium (Ca) alginate and Ca-alginate + chitosan shell matrices and the powder was obtained in a single step through spray drying. The single-step process was compared to carrying out the complex coacervation and drying processes in two steps using freeze drying, in which α-amylase was encapsulated by carrying out the complexation process in the above-mentioned shell matrices using the same three-fluid atomizer and collecting the coacervates, which were subsequently freeze dried. The results showed that the microcapsules obtained from the single-step encapsulation process (three-fluid nozzle spray drying) had smaller particle sizes, were less porous, and provided better enzyme stability compared to the microcapsules obtained by carrying out the complexation and drying in two steps and the single-step process was faster. It was observed that the egg-box structure was formed in both types of powder particles; however, the complexation with chitosan partially disrupted the formation of this structure. The three-fluid nozzle–based spray drying is a promising technology in which both the complex coacervation and drying processes can be carried out in a single step.     

Influence of Spray Drying Parameters on the Formation of β-Phase Poly(vinylidene fluoride)

A simple one-step spraying method to produce poly(vinylidene fluoride) (PVDF) in the desired conformation is presented. The content of the piezoelectric β-phase is measured at different spray drying conditions and during electrospray. The influence of a strong electrical field and charges on the droplet are investigated separately from the electrospray setup with a pneumatic atomizer. For this purpose, the electric field is integrated into a pneumatic atomization process by a plate capacitor and the charge of the droplets by corona discharge. To investigate the drying properties, the drying temperature and the flow rate of dry air are examined. The presented process offers the possibility to deposit PVDF films or to produce PVDF powders, in their piezoelectric β- and γ-phases or in the nonpolar α-phase.     

Preparation and Characterization of Layered Double Hydroxides – PMMA Nanocomposites by Solution Polymerization

Layered double hydroxides (LDH) – poly(methyl methacrylate) (PMMA) intercalated-exfoliated nanocomposites were synthesized by solution polymerization of methyl methacrylate (MMA) in the presence of aminobenzoate organically-modified LDH. Preparations of 4-aminobenzoate organically modified LDHs were carried out by applying a chemical co-precipitation reaction. Structural and compositional details of LDH-AB were obtained with Fourier transformed infrared (FT-IR) spectroscopy, ²⁷Al magic-angle spinning nuclear magnetic resonance (²⁷Al MAS NMR), elemental analysis (EA), inductively coupled plasma (ICP) atomic absorption spectrometry and X-ray diffraction (XRD). The morphology of the LDH-AB in the PMMA matrix was identified by employing transmission electron microscopy (TEM), XRD, and UV/visible transmission spectroscopy. The thermal properties of the nanocomposites were enhanced and their Tg values as well as the decomposition temperatures shifted to a high temperature region as identified by the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). For example, the Tg value and the decomposition temperature of the nanocomposites with 6.4% LDH-AB increased by 19 °C and 24 °C, respectively.     

Preparation of Sesaminol from Sesaminol Triglucoside by β-Glucosidase and Cellulase Hydrolysis

Sesaminol triglucoside (i.e., 2,6‐O‐di(β‐d ‐glucopyranosyl)‐β‐d ‐glucopyranosyl sesaminol, STG) is a physiologically active substance obtained abundantly from defatted sesame cake. Since, the industrial preparation of sesaminol from STG has not been reported previously, the aim of this research was to prepare sesaminol by hydrolysis of STG using β‐glucosidase and cellulase. Under the optimal conditions of total enzyme dosage 100 μL (8,000.72 U), the ratio of β‐glucosidase and cellulase 20:80 (v/v) (0.72:8,000, U/U), reaction time 24 h, substrate concentration 6 mg/mL, reaction temperature 50 °C, and reaction system pH 4.8, the yield of sesaminol was 48.9 %. Further, sesaminol and other hydrolysis products (sesaminol diglucoside and sesaminol monoglucoside) were successfully determined by high performance liquid chromatography and electrospray ionization/mass spectrometry.     

Removal of Nitrophenols by Adsorption Using β-Cyclodextrin Modified Zeolites

Removal of nitrophenols (NPs) from aqueous solutions through the adsorption process by using cationic β-cyclodextrin (CCD) modified zeolite (CCDMZ) was investigated. The effects of particle size, contact time, solution pH values and sodium chloride content in the aqueous on adsorption capacity were evaluated through a series of batch experiments. The results showed that CCDMZ had a higher adsorption capacity for removing NPs at a size fraction of 0.45-0.9 mm while adsorption of NPs on CCDMZ reached equilibrium within 60 min. The adsorption process was apparently influenced by pH values and sodium chloride content in aqueous solution. To ascertain the mechanisms of sorption, the experimental data were modeled by using the pseudo-first and pseudo-second order kinetic equations, and the results indicated that the adsorption kinetics of NPs on CCDMZ well-matched with the pseudo-second order rate expression.     

Preparation and Characterization of Theophylline‐Imprinted Monolithic Column

Abstract

Monolithic molecularly imprinted column was prepared by an in‐situ therm‐initiated copolymerization and the effects of essential preparation conditions such as polymerization mixture composition and polymerization condition was investigated. The results showed that the selection of correct porogenic solvents and appropriate polymerization conditions are crucial for the preparation of the monolithic stationary phases. The separation efficiency was only extremely weakly dependent on flow rate and hydrogen‐bonding interaction played an important role in the retention and separation. Compared with conventional particle columns and bulk molecular imprinted polymer column, the monolithic column exhibited good stability, ease of regeneration, high separation efficiency, and fast analysis.     

Preparation and characterization of MnOOH and β-MnO2 whiskers

MnOOH and β-MnO₂ whiskers are obtained for the first time in our work. MnOOH whiskers are chemically synthesized in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB). The product is obtained under extremely low surfactant concentrations under basic conditions, using MnSO₄·H₂O as the manganese source and ethylamine as the alkali source. After the subsequent heat treatment of MnOOH at 300 °C for 1 h, β-MnO₂ whiskers retaining the similar morphologies are obtained. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetry analysis (TGA) are used to characterize the products.     

Effect of β-Cyclodextrin Complexation on Solubility and Enzymatic Conversion of Naringin

In the present paper, the effect of β-cyclodextrin (β-CD) inclusion complexation on the solubility and enzymatic hydrolysis of naringin was investigated. The inclusion complex of naringin/β-CD at the molar ratio of 1:1 was obtained by the dropping method and was characterized by differential scanning calorimetry. The solubility of naringin complexes in water at 37 ± 0.1 °C was 15 times greater than that of free naringin. Snailase-involved hydrolysis conditions were tested for the bioconversion of naringin into naringenin using the univariate experimental design. Naringin can be transformed into naringenin by snailase-involved hydrolysis. The optimum conditions for enzymatic hydrolysis were determined as follows: pH 5.0, temperature 37 °C, ratio of snailase/substrate 0.8, substrate concentration 20 mg·mL⁻¹, and reaction time 12 h. Under the optimum conditions, the transforming rate of naringenin from naringin for inclusion complexes and free naringin was 98.7% and 56.2% respectively, suggesting that β-CD complexation can improve the aqueous solubility and consequently the enzymatic hydrolysis rate of naringin.     

Preparation and Characterization of Iron Oxides – Polymer Composite Membranes

Composite membranes of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) or ethyl cellulose filled with magnetic nanoparticles, that is, ferroferric oxides (Fe₃O₄) were prepared. These membranes were examined for nitrogen and oxygen permeability. In the case of ethylcellulose membranes the gas flow was too high, since the macropore were formed. In further permeation measurements PPO membranes with 1 to 10 w/w% magnetic particles content were investigated. For the higher concentration of magnetite (more than 20%) in PPO polymer solution sedimentation phenomenon was observed. Mass transport coefficients (permeation and selectivity) were evaluated. Selectivity of the investigated membranes changed with the weight fraction of magnetic particles from oxygen (plain) towards nitrogen (2 and more w/w%).     

Preparation and Characterization of Hybrid Chitosan/PEO–Silica Membrane Doped with Phosphotungstic Acid for PEM Fuel Cell Application

In an effort to improve the proton conductivity of the s-Chitosan/PEO/s-SiO₂ membranes, a heteropoly acid such as phosphortungstic acid/Sulfosuccinic acid as a cross-linker is incorporated in the polymer matrix. The membranes show that s-SiO₂ nano particles are dispersed within the membranes uniformly and indicating the good organic compatibility of s-SiO₂ particle with PWA/SSA. The conductivity is found to increase in the order of 10^?1 Scm^?1 at 303K for increasing the PWA acid dopant. The physicochemical properties of the films are successively characterized by water uptake, IEC and mechanical stability. The results suggest that s-CS/PEO/s-SiO₂/PWA composite membranes suitable for fuel cell.     

Preparation,Characterization and Assessment of the Novel Gelatin–tamarind Gum/Carboxymethyl Tamarind Gum-Based Phase-Separated Films for Skin Tissue Engineering Applications

The current study delineates the development of novel gelatin–tamarind gum/carboxymethyl tamarind gum-based phase-separated films for probable skin tissue engineering applications. Polyethylene glycol was used as plasticizer. The films were characterized thoroughly using mechanical tester and impedance analyzer. Cell proliferation ability and drug release properties of the films were investigated. Mechanical studies indicated composition-dependent stress relaxation properties. Polysaccharide containing films supported better proliferation of human keratinocytes as compared to control. Drug-loaded films showed good antimicrobial properties against Escherichia coli. Analysis of the results indicated that the prepared films may be tried as matrices for skin tissue engineering.     

Synthesis and Characterization of the Inclusion Complex of β-cyclodextrin and Azomethine

A β-cyclodextrin (β-Cyd) inclusion complex containing azomethine as a guest was prepared by kneading method with aliquot addition of ethanol. The product was characterized by Fourier Transform Infrared (FTIR) spectrometer, ¹H Nuclear Magnetic Resonance (¹H NMR) and Thermogravimetric Analyzer (TGA), which proves the formation of the inclusion complex where the benzyl part of azomethine has been encapsulated by the hydrophobic cavity of β-Cyd. The interaction of β-Cyd and azomethine was also analyzed by means of spectrometry by UV-Vis spectrophotometer to determine the formation constant. The formation constant was calculated by using a modified Benesi-Hildebrand equation at 25 °C. The apparent formation constant obtained was 1.29 × 10⁴ L/mol. Besides that, the stoichiometry ratio was also determined to be 1:1 for the inclusion complex of β-Cyd with azomethine.     

Optimization of the Spray Drying Operating Parameters—A Quick Trial-and-Error Method

This short communication reports an optimization approach to effectively determine suitable spray drying operating parameters for a pilot-scale dryer. The proposed optimization approach is essential, as pilot-scale investigations and medium-scale contract productions often involve usage of standard spray dryer units which is not specifically designed for the feed material used. This optimization approach was developed based on past studies on the effect and relationship of the many spray drying operating parameters and highlights two factors which has to be solved (or considered) chronologically: dripping problem, followed by product caking problem. Based on this proposed approach, an algorithm was developed in a case study to optimize an available spray dryer for our future experimental study on wall deposition. In this case, the operating parameters were determined under minimal experimental runs. This proposed optimization approach will be a useful tool for operators and experimenters utilizing spray dryers of similar type, particularly in exploring new feed materials. Depending on the optimization objectives and experimental limitations, different algorithms can be developed. Apart from that, interesting deposition pattern was also observed in the case study. This short communication also reported on the design of an internal rig for further studies on wall deposition.     

Formation of Supramolecular Gels from Host–Guest Interactions between PEGylated Chitosan and α-Cyclodextrin

Chitosan-based hydrogels are prepared via the formation of polypseudorotaxanes (PPR), by selectively threading α-cyclodextrin (α-CD) macrocycles onto polymeric chains, which, through the formation of microcrystalline domains, act as junction points for the network. Specifically, host–guest inclusion complexes are formed between α-CD and PEGylated chitosan (PEG-Ch), resulting in the formation of supramolecular gels. PEG-grafted chitosan is obtained with a reaction yield of 79.8%, a high degree of grafting (50.9% GW) and water solubility (≈16 mg mL⁻¹), as assessed by turbidimetry. A range of compositions for mixtures of PEG-Ch solutions (0.2–0.8% w/w) and α-CD solutions (2−12% w/w, or 0.04–0.2% mol) are studied. Regardless of PEG content, gels are not formed at low α-CD concentrations (<4%). Dynamic rheology measurements reveal stiff gels (G’ above 15k) and a narrow linear viscoelastic region, reflecting their brittleness. The highest elastic modulus is obtained for a hydrogel composition of 0.4% PEG-Ch and 6% α-CD. Steady-state measurements, cycling between low and high shear rates, confirm the thixotropic nature of the gels, demonstrating their capacity to fully recover their mechanical properties after being exposed to high stress, making them good candidates to use as in-situ gel-forming materials for drug delivery to topical or parenteral sites.