Physical & Theoretical Chemistry
Review: Solid Dispersion Formulation Methods and Applications in Drug Delivery
About 44% of the active medicinal components in all previously disclosed chemical units are hydrophobic and do not extend shop because of their limited water solubility. One of the factors limiting the rate at which oral medications can reach the appropriate concentration in the systemic circulation for pharmacological action is their solubility. Our medical preparation scientists and researchers are constantly surrounded by issues relating to drug release drug targeting solubility overdosing permeability and bioavailability. Thus creating or improving frameworks for drug delivery is a territory of ongoing research. Solid dispersion micronization salt formation are some of the vital methods usually employed to improve the solubility of poorly soluble drugs but each method has some drawbacks and benefits. This review focuses on different methods of improving drug solubility in order to lower the proportion of medication candidates that are removed from development due to poor solubility. The popular solution for all problems related to aspects of solubility and in-vitro release rate of certain poorly water-soluble drugs is solid dispersion. Solid dispersions smear the standard to drug release via producing a combination of a poorly water-soluble API and greatly soluble coformers. The solid dispersion method has been commonly used to increase the in-vitro drug release solubility and bioavailability of poorly water-soluble drugs. The focus of this review paper is on carriers BCS classification and solubility. This page also summarizes some of the most current technological advancements and offers a variety of preparation methods for solid dispersion. The various solid dispersions were highlighted according to their molecular configuration and carrier type. It also provides an overview of the solid dispersion methodologies and their mechanics as well as the marketed medications that can be made utilizing them.
Interaction of Triethylamine with Phenylacetylene and Exciplex Formation Study in Solutions
Phenylacetylene interacts with triethylamine in the excited state. Hence the formation of weak charge transfer binary molecular complex species popularly known as exciplex has been investigated. The exciplex is formed probably due to the interaction of the excited state phenylacetylene dipole and C-H dipole of triethylamine in the non-polar aprotic solvent cyclohexane.
Exciplex formation is very much dependent on the concentration of triethylamine. Higher concentrations of triethylamine facilitate the formation of exciplex. Phenylacetylene absorbs at 271 nm wavelength and it shows a fluorescence emission peak at 298 nm. While titrating phenylacetylene against triethylamine in cyclohexane a new emission band centered on 422 nm is observed and indicates the formation of exciplex. In cyclohexane in higher quencher (triethylamine) concentration (above 14.2 mM) the inaccessible fraction of phenylacetylene is 0.48±0.06 (≈0.5) which is a close resemblance of multi-tryptophan protein in water where half of the sites are solvent inaccessible.
At lower concentrations of triethylamine the fluorescence quenching of phenylacetylene is predominantly dynamic but at higher concentrations it is complex. In ethanol the quenching of fluorescence is purely dynamic.
Therefore in very high concentrations of triethylamine fluorescence is almost saturated. The effect of solvent polarity on molecular aggregation of phenylacetylene with triethylamine has been studied.
Physicochemical Exploration of Some Biologically Potent Molecules Prevailing in Aqueous Solution of an Anticoagulant Drug with the Manifestation of Solvation Consequences
Our research aims to uncover how solute-solvent and solute-solute interactions behave in aqueous solutions exploring how temperature variations and concentration changes influence these interactions. This can provide deeper insights into the behavior of molecules in different environments potentially leading to applications in fields such as drug delivery chemical reactions and material science.
In the aqueous ternary system the physicochemical interactions between a medically powerful pharmacological molecule and two naturally occurring amino acids were explored. The investigations were performed in a dilute to infinite dilute medium to study the interactions between the solutes and solvent extensively.
The objective of this research is to systematically investigate the nature of solute-solvent and solute-solute interactions in aqueous solutions across a range of temperatures and concentrations. By doing so we aim to elucidate the underlying principles governing these interactions which could contribute to a deeper understanding of solution chemistry. This knowledge is intended to inform the development of more efficient and effective applications in various scientific and industrial fields including drug formulation catalysis and material design.
To characterize and calculate the interactions in the ternary system various models and formulas were considered and applied. Based on various parameters including viscosity B-coefficient apparent molar volume and molar conductance from viscosity density and conductance studies varying temperatures and concentrations were used to elucidate the molecular interactions. To elucidate the interactions between solute with co-solute and with solvent the limiting apparent molar volumes and the experimental slopes derived from the Masson equation and the Viscosity constants A and B obtained via the Jones-Doles equation were examined. To illustrate the structure- breaking/making character of the solutes in the solution Hepler’s method and dB/dT values were applied.
The results indicated that hydrophobic-hydrophobic interaction plays a significant role in the system.
These amino acid interaction models may explain the properties of a variety of physiologically active compounds and the mechanism can be expanded to comprehend the nature of similar systems. Furthermore the research could lead to advancements in areas such as pharmaceutical sciences where controlling solute interactions is crucial for drug delivery systems and in environmental chemistry where understanding pollutant behavior in water is essential for remediation efforts.
Green Synthesis, Structural Insights, and Antimicrobial Potential of Zinc Oxide Nanoparticles Synthesized via Sustainable Method
Green synthesized nanoparticles have gained wide interest in today’s world due to their inherent features like rapidity eco-friendliness and cost-effectiveness [4].In this study zinc oxide (ZnO) nanoparticles were synthesized using an aqueous extract of Ixora coccinea leaves. X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) studies were used to analyze the structural and morphological properties of prepared Zinc Oxide nanoparticles.
The sol-gel method of synthesis via the green route was introduced to synthesize pure Zinc oxide nanoparticles. Silver-doped Zinc Oxide nanoparticles were also prepared using the same method.
The XRD studies showed the crystalline nature and revealed the purity of Zinc Oxide nanoparticles. The specific functional groups responsible for reduction stabilization and capping agents present in the nanoparticles were examined using Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. The bacterial destruction was better for ZnO nanoparticles than reported for plant extracts and standard drugs.
This study proves that Zinc Oxide nanoparticles contain natural anti-microbial agents through green synthesis which may serve to produce drugs for antimicrobial therapeutics.
Exploring Iridium's Catalytic Role in Redox Reactions: A Concise Review
Transition metals exhibit a remarkable capacity to catalyse redox processes playing a crucial role in various natural biological and chemical transformations. Among all the elements in the periodic table iridium stands out with the broadest range of oxidation states. With its electronic configuration of 5d76s2 iridium displays a range of oxidation states fluctuating from -3 in [Ir (CO)3]3- to +9 in [IrO4]2+. The utilization of iridium as a catalyst stems from its capability to adopt these variable oxidation states. Notably Iridium (III) complexes exhibit significant catalytic activity in both acidic and basic environments facilitating a diverse array of organic and inorganic chemical transformations. The catalytic mechanism adapts according to the specific conditions under which the catalysts are employed. Iridium's catalytic efficiency is notably enhanced in an acidic environment as highlighted in this review compared to its performance in a basic medium. Iridium stands as the sole reported catalyst with the capability to harness sunlight and transform it into chemical energy offering promising prospects for application in artificial energy systems. The high surface-to-volume ratio of IrNPs contributes to their excellent catalytic performance. As research in Nanocatalysis continues to evolve iridium remains a key player in shaping the future of sustainable and efficient chemical processes.
Investigation of the Effects of Different Phases of TiO2 Nanoparticles on PVA Membranes
PVA/TiO2 nanocomposite membranes are prepared by solution casting technique where different phases of TiO2 nanoparticles like brookite brookite-rutile and rutile are dispersed in PVA matrix. Sol-gel method was employed to prepare TiO2 nanoparticles while different phases of TiO2 have been obtained by controlling the calcination temperature.
PVA/TiO2 nanocomposite membranes were characterized by XRD FTIR AFM TEM UV-visible and PL techniques. XRD results confirmed the presence of different phases of TiO2 exhibiting 3.3 nm 8.4 nm and 35.7 nm mean crystalline size. The XRD studies also confirmed that TiO2 nanoparticles became properly dispersed to the PVA matrix leading to increased PVA crystallinity after doping of different phases of TiO2 nanoparticles. UV-visible analysis revealed an increase in absorption intensity and peak position shifts slightly towards longer wavelengths which indicates that nanofillers tuned the band gap of PVA. The doping of the TiO2 (brookite) phase in the PVA matrix results in a decreased in PL intensity.
This suggests that the PVA/TiO2 (brookite) membrane exhibits a greater degree of photocatalytic activity in comparison to the other two composites. According to the FTIR investigation the hydroxyl (OH) groups present in PVA interact with the dopants Ti+ ions via intra- and intermolecular hydrogen bonds to produce charge transfer complexes (CTC). The AFM study shows surface roughness details for PVA and PVA/TiO2 composite membranes. The average grain size of TiO2 nanoparticles calculated from TEM images is in good agreement with the grain size calculated by XRD.
By adjusting the phase of TiO2 nanoparticles into PVA matrix composites can be developed that are optimized for a variety of applications such as water purification UV protection self-cleaning surfaces lithium-ion batteries and optoelectronic devices.
A Kinetic and Mechanistic Study of Ir (III)-Catalyzed Oxidation of Methionine by HCF (III) in an Aqueous Alkaline Medium
The kinetic study of Ir (III) chloride-catalyzed oxidation of methionine by hexacyanoferrate (abbreviated as HCF) III ions in aqueous alkaline medium was performed spectrophotometrically at constant ionic strength of 0.5 moldm-3 and temperature of 35±0.1°C.
The progress of the reaction was found to be first-order rate dependence kinetics with respect to [HCF (III)] [OH-] and [IrCl3]. The rate of reaction was found to decrease with an increased concentration of methionine. The ionic strength of the reaction mixture showed a positive salt effect on the reaction rate. Different activation parameters were also evaluated by studying the reaction at four different temperatures. The stoichiometry of the reaction showed Methionine: HCF (III) = 1:4.
The oxidation product of the reaction was found to be methionine sulphone which was identified by an organic solvent method and IR Spectroscopy. Further a suitable mechanism was proposed to explain all the experimental results.
It is assumed that the reaction proceeded through complex formation between substrate (oxidant) and iridium trichloride. A rate law was derived which verified the results.
CH3-S-(CH2)2-CH (NH2)-COO- + 4HCF (III) 
CH3-SO2-(CH2)2-CH-(NH2)-COO- + 4HCF (II)
Ionic Liquid-Based Green Solvents for Extraction and Purification of Natural Plant Products
This research paper explores the environmental sustainability of ionic liquid-based green solvents in the extraction and purification of natural plant products with a focus on their entire life cycle. The objectives of the study were to assess the environmental impact of ionic liquid synthesis energy consumption water usage emissions recycling rates policy effects and stakeholder perceptions.
Methodologically we conducted a comprehensive Life Cycle Assessment (LCA) that involved primary data collection through field surveys and interviews with key stakeholders in the ionic liquid production and usage industry across various regions in India. The data were analyzed using specialized LCA software tools to quantify environmental impacts. Key findings include the identification of synthesis as a major contributor to environmental impact emphasizing the need for greener synthesis methods.
The study revealed the significant carbon footprint energy consumption and water usage during production highlighting opportunities for improvement. Emissions data underscored the importance of emission control measures particularly for greenhouse gases and volatile organic compounds. Recycling and reuse were identified as environmentally friendly disposal methods. Policy compliance varied among stakeholders indicating room for stricter regulations. Stakeholder perceptions varied with researchers having the most positive outlook. Implications of the findings extend to sustainable chemistry practices emphasizing interdisciplinary collaboration and the importance of considering the entire life cycle of chemical processes.
This research contributes to a deeper understanding of green solvents and provides a foundation for promoting sustainable practices in industrial processes in India and globally.
Spectrophotometric Determination of Curcumin using 3-Methyl-2-benzothiazolinone Hydrazone Hydrochloride Hydrate as Electrophilic Coupling Agent
Nutraceuticals are products derived from food sources that provide extra health benefits in addition to the basic nutritional value found in foods. Spectrophotometric methods for the determination of curcumin were developed which are simple sensitive selective rapid and reliable.
The methods are based on the reduction of iron (III) to iron (II) by 3-Methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH) which is an electrophilic coupling agent and subsequent reaction with curcumin in mild hydrochloric acid medium. Spectrophotometric methods for the determination of curcumin were developed which are simple sensitive selective rapid and reliable. The methods are based on the reduction of iron (III) to iron (II) by 3-Methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH) which is an electrophilic coupling agent and subsequent reaction with curcumin in mild hydrochloric acid medium.
The reaction produces a bluish–green complex with maximum absorbance at 670 nm. The colour complex can be extracted into chloroform. The methods obey Beer’s law in the range 0.3-7.0 and 0.2-7.0 (µg mL-1).
10 common anions and cations were added and the method was tested and no interference was observed. The proposed methods offered the advantages of having good reproducibility and were satisfactorily worked out to estimate the amount of curcumin in various turmeric samples.
Thermo-Gravimetric Studies and Specific Heat Capacity Estimations of the Products of Biginelli Reaction using TGA-DSC
In this work the thermal behavior and specific heat capacities of nine derivatives which were obtained via Biginellipyrimidone synthesis reaction have been experimentally determined using thermal gravimetry analysis and differential scanning calorimetry and the obtained results have been thoroughly analyzed and discussed. The influence of the structural variation on the thermal analysis has been discussed along with the influence of the structure of the derivatives of pyrimidines on the specific heat capacity.
To date heterocycles have successfully been switched from synthetic organic chemistry laboratory to the core of a variety of biomolecules conducting devices and so on. Derivatives of 2-hydroxypyrimidine or pyrimidines have a wide window of pharmaceutical applications. Therefore attempts have been made to understand the thermal response of these organic frameworks.
The main objective of this study was to explore thermal methods to understand heat-induced structural interactions as well as the specific heat capacity (Cp) as a function of temperature for the synthesized derivatives of 2-hydroxy pyrimidine or pyrimidones.
Room temperature condensation of ethyl acetoacetate urea and variety of aldehydes or ketones has been optimized in ionic liquids for the formation of pyrimidones. Thereafter the thermal profiles of the synthesized derivatives of pyrimidines have been studied thoroughly and the thermal response of the synthesized derivatives of pyrimidones gives sound information about thermal stability of these heterocycles.
In the present work the effect of substituents on the thermal behavior of the synthesized derivatives of pyrimidines has been investigated with the help of TGA-DSC analysis. Specific heat capacity (Cp) data as a function of temperature for the synthesized derivatives of pyrimidones have been reported for the first time.
The specific heat capacity data of the molecules of high commercial and biological relevance such as pyrimidines like organic frameworks play a subtle role in the development of the computational methods and molecular modelling to comprehend the fundamentals of these molecular frameworks and effectively explore the pharmaceutical as well as materialistic potentials of these heterocyclic frameworks via simulation.
Exploring Structural and Optical Properties of Nanoparticles of Barium Titanate and Iron doped Barium Titanate and Their Potential Application in Antibacterial Activity
Barium Titanate (BaTiO3) is a good candidate for a variety of applications due to its excellent dielectric ferroelectric and piezoelectric properties.
Pure and doped Barium Titanate (BTO) nanoparticles have been synthesized by the sol-gel method. Barium hydroxide octahydrate (Ba (OH)2.8H2O) and titanium (IV) iso-propoxide (Ti {OCH[CH3]2}4) were used as starting materials. Apart from pure Barium Titanate nanoparticles Fe-doped BaTiO3 nanoparticles of three different concentrations: 0.1 0.2 and 0.3 in mol% were prepared and characterized using X-ray diffraction (XRD) UV visible spectroscopy Fourier Transform Infrared Spectroscopy (FTIR).
From the X-ray diffraction pattern the particle size was found to be varied in a range of 17-25nm. By using UV visible spectroscopy it was observed that the band gap energy of pure BaTiO3 NP is 3.2eV. As the pure BaTiO3 nanoparticles are doped with 0.1% Fe the band gap reduces to 3.175eV. For BaTiO3 doped with 0.2% and 0.3% Fe the band gap energy values are 2.709 and 2.652 respectively. FTIR spectra were used to analyze the vibrational modes of BaTiO3. From the result obtained from FTIR we can see that the absorption spectrum ranges from 450cm-1-4000cm-1. The prominent peak of pure BaTiO3 is at 500cm-1 which is due to the vibration of the Ti-O band in crystal lattice. For BaTiO3 doped with Fe2O3 the wave number of the absorption peak is shifted from 500cm-1 in pure BaTiO3. The antibacterial studies were conducted on Pseudomonas aeruginosa Staphylococcus aureus and Escherichia coli.
Both pure and iron-doped Barium Titanate showed significant antibacterial properties confirming the antibacterial property of Barium Titanate nanoparticles.
Spectrophotometric Analysis of Edible Salt for Iodate Quantities
The Spectrophotometric method was used to identify iodate by utilizing a class of antidepressants known as imipramine hydrochloride (IPH) desipramine hydrochloride (DPH) clomipramine hydrochloride (CPH) and trimipramine hydrochloride (TPM).
Iodate in nano amounts can be measured using this method in an acidic medium with 3-methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH) acting as an electrophilic coupling reagent. The MBTH-IPH/DPH/CPH/TPM method had a blue with a maximum absorbance at 630 nm. Beer 's law was followed and the blue color that was produced remained stable for up to 24 hours at room temperature (270C).
The boundaries depending on the situation for the assessment of the strategy like molar absorptivity and Sandell's sensitivity gave various qualities with various reagents. The method was tested with interference from common 11 cations and 8 anions and the results obtained were within a reasonable range.
The procedure was used for the determination of iodate in iodized edible salts because iodate is one of the common ions in iodized salt. It was found that the method is reliable and can be used effectively for the determination.
The Dynamic Impact of Synthetic Dyes on the Physicochemical Parameters of Cationic and Anionic Surfactants
The interaction of dyes (crystal violet malachite green and congo red) with cationic (cetrimide) and anionic surfactants (sodium dodecyl sulfate) in the aqueous medium were studied via conductometric and UV-visible spectroscopy.
The critical micelle concentration (CMC) of both cetrimide and SDS upsurges in all the selected dyes on increasing the temperature. Thermodynamic parameters like change in Gibb’s free energy of micellization () change in enthalpy of micellization () as well as change in entropy of micellization () were calculated by employing mass action model.
The values obtained are positive with and values being negative signified that the phenomenon of micellization is spontaneous as well as exothermic in nature. Moreover the more negative in water as well as in the presence of dyes signify the presence of electrostatic forces of attraction between the oppositively charged dyes and surfactant moieties. UV-spectroscopy reveals that spectral changes occur because of the interaction of surfactants with dye molecules.
By analyzing shifts in absorption peaks changes in intensity and alterations in band shape insights into the nature of surfactant-dye complexes and their potential applications in various industries can be assessed. This understanding can help in the design and optimization of products and processes involving surfactants and dyes.
A Study of Micellar Catalyses on Oxidation of Glycine by QDC in the Presence of Sodium Dodecyl Sulphate (SDS) in Aqueous
Aims: To study the micellar effect of SDS on the oxidation of glycine by Quinolinium Dichromate (QDC) in perchloric acid medium.
Background: Among the amino acids glycine plays a major role in multiple metabolic reactions such as glutathione synthesis and one-carbon metabolism. The oxidation of glycine has received importance because it is the major neurotransmitter inhibitor in the spinal cord and brainstem. In the oxidation process of amino acids highly toxic chromium (VI) compounds are converted into non-toxic chromium (III) by quinolinium dichromate (QDC) oxidant in an appropriate pH value medium.
Objective: 1. To study the catalytic role of anionic surfactant (SDS) on the oxidation of glycine by QDC through micellization evaluation of critical micelles concentration (CMC) in the presence and absence of glycine and other surface properties along with thermodynamic quantities. 2. Determination of rate constant and order of reaction with respect to QDC glycine acid and surfactant which will help to study the kinetics of the reaction 3. Analysis of oxidation product by FT-IR and calculation of activation parameters. 4. Synthesis of oxidant (QDC) and its characterization by UV-Visible spectrophotometer and NMR spectroscopy.
Methods: The reaction was monitored spectrophotometrically at λmax = 440 nm using Systronics Spectrophotometer-166 and 2203. The reaction mixture containing glycine perchloric acid SDS and water was taken in a separate flask in a thermostat and the oxidation reaction was started by adding the required amount of oxidant.
Results: First-order kinetics was observed with respect to oxidant glycine and hydrogen ions. The rate of reaction increased remarkably with an increase in the concentration of surfactant (SDS). The kinetic results show that the ionic strength variation does not have any significant effect on the rate whereas the increase in the dielectric constant of the medium shows a remarkable effect on the rate constant. From stoichiometry study it was found that 2 moles of oxidant (QDC) consumed 3 moles of glycine to produce aldehyde (Formaldehyde).
Conclusion: The observed negative value of (ΔS) entropy of activation and positive (ΔH) enthalpy of activation suggests a more ordered activated complex formation and highly solvated transition state. The kinetics of the reaction in a perchloric acid medium is found to be accelerated in the presence of surfactant (SDS). The kinetics of the reaction follow pseudo first-order decay of Cr(VI) species (QDC) a unity dependence of rate on glycine and perchloric acid. The oxidation product formaldehyde was identified by FTIR. NMR spectrum analysis of synthesized QDC shows a resemblance with pure QDC.
Effects of MWCNTs on the Improved Mechanical Characteristics of Cementitious Composite
Concrete's filler material gets strengthened over time by specific chemical reactions that harden it. Multi-walled carbon nanotubes (MWCNTs) are more frequently used as fillers than SWCNTs owing to their lower cost of production and their superior reinforcement properties in cement composites.
Mechanical properties like compressive strength splitting tensile strength and modulus of elasticity are proportional to the water/cement ratio (w/c) and are considered critical criteria in the design of structural elements.
The aim of the present work was to prepare characterize and determine the effects that multi-walled carbon nanotubes (MWCNTs) can have on the mechanical strength of various matrix cementitious composites.
The results showed that the addition of multi-walled carbon nanotubes to the concrete greatly improved both its compressive strength and its splitting tensile strength.
Modulation of Solid-state Thermal Reaction of Iron(III)Citrate by a Co-precursor Studied using Thermogravimetry: Evaluation of Kinetic and Thermodynamic Parameters and Nucleation Rate
Background: Solid state reaction of iron(III)citrate leads to a range of ironbased oxides by varying the reaction conditions e.g. the presence of co-precursor. The influence of reaction conditions on the kinetics of the solid-state reaction of iron(III)citrate needs to be investigated. Objective: Kinetic analysis of the solid-state reaction of iron(III)citrate in the presence of a co-precursor has been explored to realize the influences of the co-precursor on the reaction process as well as decomposed material. Methods: Non-isothermal thermogravimetry profiles are deconvoluted to individual reaction steps. The model-free kinetic methodology is utilized to estimate step-wise activation energy and hence the reaction mechanism along with the reaction rate. Conversiondependent thermodynamic parameters and nucleation rate are estimated. XRD analysis has been used to characterize the decomposed material. Results: Thermogravimetry profiles obtained for an iron(III)citrate and malonic acid mixture are deconvoluted into six steps. The decomposed nanomaterial is identified as magnetite (size 10 nm). The observed reaction mechanisms associated with each step are different where the activation/reaction rate is conversion-dependent. A good fit between the experimental and reverse-constructed conversion profiles is obtained. The nucleation rate at higher temperatures is affected by both the extent of conversion and the heating rate. A possible reaction pathway is proposed. The study elucidates the role of malonic acid as a co-precursor in modifying the thermal reaction of iron(III)citrate and product formation. Conclusion: This investigation proposes the applicability of suitable co-precursors as a potential controlling factor for preparing iron oxides from iron-based compounds.
Biopolymers and their Nanocomposites: Current Status and Future Prospects
For many years petroleum-based polymers have been successfully enhanced by the addition of nanoparticles as additives. Carbon nanotubes graphene nanoclays 2-D layered materials and cellulose nano whiskers are a few of the several nanoreinforcements that are currently being researched. In comparison to unmodified polymer resin the use of these nanofillers with bio-based polymers could improve a wide range of physical properties including barrier flame resistance thermal stability solvent uptake and rate of biodegradability. This nano-reinforcement is a very appealing method to create new functional biomaterials for a variety of applications because these enhancements are typically achieved at minimal filler content.
Modulation of Triton X-100 Aqueous Micelle Interface by Ionic Liquid: A Molecular Level Interaction Studied by Time-resolved Fluorescence Spectroscopy
Background: Self-assembly structure is an important area of research for understanding biological systems owing to its resemblance to the membrane structure of the phospholipid bilayer. In a self-assembly medium chemical reactions and chemical or physical processes are dramatically different than the bulk phase. Understanding this process in synthesizing self-assembly structures may allow us to explore various biological processes occurring in cell membranes. Objective: The study aimed to understand water dynamics in the TX-100 micellar interface via steady state and a time-resolved fluorescence spectroscopy study. The objective was also to determine the two different ionic liquids (ILs) namely 1-butyl-3-methyl imidazolium tetrafluoroborate ([bmim][BF4]) and 1-decyl-3-methyl imidazolium tetrafluoroborate ([dmim][BF4]) inducing surfactant aggregation changes at the molecular level. Also the focus was on determining the hydration and its dynamics at the palisade layer of TX-100 micelle in the presence of two different ionic liquids. Methods: Steady state and time-resolved fluorescence spectroscopy have been used to study TX-100 micellar systems. Employing time-resolved spectroscopy two chemical dynamic processes solvation dynamics and rotational relaxation dynamics have been studied to investigate structural changes in TX100 by adding ILs. Solvation dynamics was studied by measuring the time-dependent Stokes shift of the fluorescent probe. From the Stokes shift time-resolved emission spectra were constructed to quantify the solvation dynamics. Also using the polarization properties of light time-resolved anisotropy was constructed to explore the rotation relaxation of the probe molecule. Results: The absorption and emission spectra of C-153 in TX-100 were red-shifted in the presence of both the ILs. Also the C-153 experienced faster solvation dynamics and rotational relaxation with the addition of both ILs. In our previous study we observed a significantly increased rate of solvation dynamics with the addition of [bmim][BF4] (J. Phys. Chem. B 115 6957-6963) [38]. However with the addition of the same amount of [dmim][BF4] the IL rate of solvation enhancement was more pronounced than with [bmim][BF4]. The faster solvation and rotational relaxation have been found to be associated with the penetration of more free water at the TX100 micellar stern layer leading to increased fluidity of the micellar interface. Conclusion: Upon incorporating ILs in TX100 micelle substantially faster solvation dynamics of water as well as rotational relaxation dynamics of C-153 have been observed. By decreasing surfactant aggregations [bmim][BF4] ILs facilitated more water molecules approaching the TX-100 micellar phase. On the other hand [dmim][BF4] ILs comprising mixed micelles induced even more free water molecules at the palisade layer yielding faster solvation dynamics in comparison to pure TX-100 micelle or TX100 micelle + [bmim][BF4] ILs systems. Time-resolved anisotropy study has also supported the finding and strengthened the solvation dynamics observation.
pH-Sensitive Polymers with their Important Applications (A Review)
Materials that modify their chemical or physical characteristics in reaction to diverse stimuli such as moisture heat water or pH are commonly known as smart materials or stimuli-responsive polymers. Typical applications for these polymers include catalysis finishing and coating processes. Tissue engineering drug delivery and gene transportation are additional applications that have emerged in the past two decades. As a result their potential use extends to a wider range of applications encompassing chemical processes drug delivery body-site targeting separation membrane activity sensing and actuation and agriculture. Recently pH-responsive polymers have garnered considerable interest for implementation in membrane and 4D printing. The current review work encompasses previously published research through 2022 with a particular focus on the critical application of pH-sensitive polymers.