AN OPTICAL APPARATUS FOR REAL-TIME MONITORING OF AN ONGOING CHEMICAL REACTION IN A SAMPLE SOLUTION

Abstract

ABSTRACT AN OPTICAL APPARATUS FOR REAL-TIME MONITORING OF AN ONGOING CHEMICAL REACTION IN A SAMPLE SOLUTION The present invention describes an optical apparatus for real-time monitoring of ongoing chemical reactions in a sample solution. The apparatus comprises a light source (1) that generates a light beam transmitted through an input optical fiber (2). A first convex lens (4) collimates the light into a parallel beam, which interacts with the sample solution held in a sample holder (11) positioned on a hot plate stirrer (12) for simultaneous heating and stirring during the reaction. A second convex lens (6) re-collimates the transmitted and scattered light after passing through the sample, and an objective lens (7) focuses this light before it enters an output optical fiber (9). The light is then transmitted to a spectrometer (10), where the generated spectra are analyzed for real-time monitoring of reaction parameters such as particle size, shape, concentration, and other spectral shifts. REF. TO FIGURE 1A

Specification

Description:FORM 2
THE PATENTS ACT 1970
39 of 1970
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See sections 10 & rule 13)
TITLE OF THE INVENTION

"AN OPTICAL APPARATUS FOR REAL-TIME MONITORING OF AN ONGOING CHEMICAL REACTION IN A SAMPLE SOLUTION"
APPLICANTS (S)
NAME NATIONALITY ADDRESS
INDIAN INSTITUTE OF TECHNOLOGY HYDERABAD An Indian Educational Institute IIT Hyderabad Road, near NH-65, Kandi, Sangareddy, Hyderabad, Telangana-502284, India

PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed







AN OPTICAL APPARATUS FOR REAL-TIME MONITORING OF AN ONGOING CHEMICAL REACTION IN A SAMPLE SOLUTION

FIELD OF THE INVENTION
The present invention relates to monitoring of chemical reactions. In particular, the present invention relates to an optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution.

BACKGROUND OF THE INVENTION
Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Collecting information only at the beginning and end of a chemical reaction often leads to missing critical details that occur during the process itself. In the study of nucleation and growth of plasmonic nanoparticles, the color change during the reaction is particularly significant. This color change is primarily caused by the formation of particles of different sizes at various stages of the synthesis. Understanding the reaction dynamics and the correlation between color and particle shape or size is crucial. The introduction of specific chemicals during the synthesis process can influence the formation of different shapes and sizes, and this change can be tracked by monitoring the color variation.
One of the challenges is that color changes in many reactions occur rapidly, making it difficult to monitor using traditional methods. The invention provides a solution to the traditional problems.
Several setups exist commercially, though they have limitations as discussed here. Conventional UV-visible spectroscopy systems require aliquots of the sample to be placed in a cuvette for analysis may lead to volume loss and the possibility of affecting the reaction process.
While some systems can record time-dependent data, they are typically limited to room temperature measurements without the capability for in-situ heating or stirring, therefore, in-situ monitoring of the analyte solution while heating and stirring is currently not feasible with existing systems. Further, pH meters, coupled with stirrers, can perform time-dependent measurements by dipping the probe into the solution, but these systems work on a different principle (not absorption spectroscopy), which is undesirable, especially in sensitive reactions. Furthermore, heating stirrers and hot plates are available but lack provisions for collecting spectral data in real time during the reaction process. Further, transferring samples from a hotplate to a UV-visible spectroscopy setup can result in ambiguity due to time delays, leading to inaccurate data.
Therefore, there is strong need to provide an apparatus that enables continuous, and real-time monitoring of a chemical reaction by using UV-Vis spectrum during chemical synthesis, specifically while the reaction is being stirred and heated.
Other aspects and advantages of the present disclosure will become apparent from the following description, taken in connection with the accompanying drawings which by way of example illustrate exemplary embodiments of the present invention.

OBJECTS OF THE INVENTION
It is therefore the object of the present disclosure to overcome the aforementioned and other drawbacks in prior arts.
The primary objective of this invention is to develop an apparatus capable of real-time monitoring of on-going chemical reactions.
Another object of the present disclosure is to propose the apparatus to enable continuous monitoring and collection of UV-Vis spectra throughout the chemical reaction process without the need to remove samples, ensuring that every stage of the reaction is monitored.
Yet another object of the present disclosure is to propose the apparatus that allows for non-invasive, in-situ analysis of chemical reactions while simultaneously heating and stirring the reaction mixture, capturing critical reaction dynamics.
A still another object of the present disclosure is to allow precise tracking of reaction dynamics, such as color changes and spectrum peak shifts, which are directly related to particle size, shape, and concentration changes during synthesis or chemical transformations.
These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.

SUMMARY OF THE INVENTION
One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
Solution to one or more drawbacks of existing technology and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
The present disclosure relates to an optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution. The present system comprises several components designed to collect and analyze light as it interacts with the reaction. The apparatus includes a light source that generates a light beam, which is directed into an input optical fiber. The input optical fiber is adapted for receiving the light beam from the light source, at one end and transmitting it towards another end. The input optical fiber is optically aligned with the light source. This fiber transmits the beam to the apparatus's optical components, where a first convex lens collimates the light into a parallel beam. The collimated light then passes through a sample holder containing the reaction solution, while a hot plate stirrer beneath the sample holder provides heating and stirring during the reaction. After interacting with the sample, the transmitted and scattered light is re-collimated by a second convex lens. An objective lens focuses the re-collimated light, which is then directed into an output optical fiber. The output optical fiber is aligned to the objective lens and adapted for receiving the re-collimated light at one end and transmitting it towards another end of the fiber. The output optical fiber transmits the light to a spectrometer, which collects the light and generates spectra. The generated spectra are analyzed in real-time to monitor the chemical reaction as it progresses in the sample solution.
In an aspect of the invention, the present apparatus analyzes the spectra to determine the absorbance and transmittance of the sample solution, particularly when a color change occurs during the ongoing chemical reaction.
In a further aspect of the invention, the apparatus determines the absorbance of the sample solution by measuring the intensity of the spectra at each wavelength and calculating the logarithmic ratio of the measured intensity.
In a further aspect of the invention, the apparatus identifies the presence of a predefined shape of particles in the sample solution based on one or more absorbance peaks. The position of these peaks indicates the absorbance resonance in the transverse and longitudinal directions of the particle shape, while the peak intensity defines the concentration of particles.
In a further aspect of the invention, the apparatus determines the presence of different-sized particles of a predefined shape in the sample solution based on absorbance peaks. Higher wavelength peaks correspond to larger particles, and lower wavelength peaks correspond to smaller particles, with peak intensity defining the concentration..
In a further aspect of the invention, a spectrometer is configured to collect real-time UV-Vis spectra while the sample solution is heated and stirred, enabling continuous monitoring of nanoparticle synthesis and capturing spectral changes due to the addition of various chemicals during the ongoing chemical reaction.
In a further aspect of the invention, the apparatus determines the pH of the ongoing chemical reaction by studying the color change spectrum of a pH indicator present in the solution.
In a further aspect of the invention, the apparatus includes a light source that can be a tungsten filament or a UV lamp.
In a further aspect of the invention, the apparatus features an input optical fiber configured to direct light from the light source to the first convex lens, which collimates the light beam onto the sample solution.
In a further aspect of the invention, includes a sample holder that holds a transparent reaction vessel containing the sample solution, ensuring it remains in the optical path of the light beam for continuous monitoring.
In a further aspect of the invention, the apparatus features a second convex lens that re-collimates the light transmitted or scattered by the sample solution, preserving the integrity of the light beam before focusing.
In a further aspect of the invention, the apparatus includes an objective lens that focuses the re-collimated light into the output optical fiber, maximizing the intensity of the re-collimated light.
In a further aspect of the invention, the apparatus has an output optical fiber that transmits the focused light to the spectrometer, enabling the measurement of spectra in real-time at nanosecond intervals.
In a further aspect of the invention, the apparatus incorporates a hot plate stirrer that provides uniform heating and stirring, utilizing at least one magnetic bead in the sample solution to maintain homogeneous conditions during the monitoring of the chemical reaction.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the present disclosure may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
Fig 1(a) illustrates the schematic of the optical apparatus, in accordance with the present embodiment;
Fig 1(b) illustrates the top and side view of the optical apparatus, in accordance with the present embodiment;
Figure 2(a), illustrates the wavelength vs time surface plot shows two major peak shifts;
Figure 2(b) the absorption vs wavelength plot shows the longitudinal peak shift from 570 nm to 730 nm during the duration of synthesis;
Figure 3(a), illustrates the wavelength vs time surface plot shows the two major peak shifts;
Figure 3(b), illustrates the absorption vs wavelength plot shows the longitudinal peak shift from 750 - 675 nm during the duration of heating;
Figure 4(a) The wavelength vs time surface plot shows the major peak value change in the 600 nm region; and
Figure 4(b) the absorption vs. wavelength plot shows both the peak values change in the 450 nm and 600 nm regions.
A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
The figure depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAIL DESCRIPTION OF INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF THE PREFERRED EMBODIMENTS:
While the embodiments of the disclosure are subject to various modifications and alternative forms, a specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms "comprises", "comprising", or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by "comprises… a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
The invention relates to an optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution. The apparatus allows for continuous observation of changes in the absorption spectra during a reaction, providing detailed information on particle size, concentration, shape, and reaction dynamics. The apparatus is built around a stirring hot plate and uses a range of optical components for precise spectrum collection.
In an aspect of the present invention, an optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution is described. The optical apparatus includes a light source, an input optical fiber, a first convex lens, a sample holder, a hot plate stirrer, a second convex lens, an objective lens, an output optical fiber, and a spectrometer. The light source is adapted for generating a light beam. The input optical fiber is adapted for receiving the light beam from the light source, at one end and transmitting it towards another end. The input optical fiber is optically aligned with the light source. The first convex lens is aligned with the input optical fiber and adapted for collimating the light beam, received from another end of the input optical fiber, to a parallel beam of light. The sample holder is adapted for holding the sample solution to be monitored, in a path of the collimated beam of light. The hot plate stirrer beneath the sample holder is adapted for heating and stirring the sample solution during the ongoing chemical reaction. The second convex lens is positioned after the sample solution for re-collimating a transmitted and scattered light, after passing through the chemical reaction in the sample solution. The objective lens is positioned after the second convex lens and adapted for focusing the re-collimated light. The output optical fiber is aligned to the objective lens and adapted for receiving the re-collimated light at one end and transmitting it towards another end of the fiber. The spectrometer is coupled to another end of the output optical fiber and configured for collecting the re-collimated light and generating spectra from the collected re-collimated light. The generated spectra is analyzed for real-time monitoring of the ongoing chemical reaction in the sample solution.
In an embodiment of the present invention, the spectra is analyzed to determine absorbance and transmittance of the sample solution to identify the colour change during the ongoing chemical reaction.
In another embodiment of the present invention, the absorbance of the sample solution is determined by measuring an intensity of the spectra at each wavelength, followed by measuring a logarithmic ratio of the intensity.
In another embodiment of the present invention, a presence of a plurality of particles of a predefined shape in the sample solution is determined based on one or more peaks of the absorbance. Further, an absorbance peak position gives an absorbance resonance in transverse and longitudinal direction of the particle shape and a peak intensity defines a particle concentration.
In another embodiment of the present invention, a presence of different size particles of a predefined shape in the sample solution is determined based on one or more peaks of the absorbance. Further, an absorbance peak position at a higher wavelength is for bigger size particles and the absorbance peak position at lower wavelength is for smaller size particles, and a peak intensity defines the particle concentration.
In another embodiment of the present invention, the spectrometer is configured to collect real-time UV-Vis spectra while the sample solution is heated and stirred, for continuous monitoring of a nanoparticle synthesis and recording color change spectrum due to addition of different chemicals during the ongoing chemical reaction.
In another embodiment of the present invention, the pH of ongoing chemical reaction is determined by studying the color change spectrum of the pH indicator present in the solution.
In another embodiment of the present invention, the light source is a tungsten filament or a UV lamp.
In another embodiment of the present invention, the input optical fiber is configured to direct the light from the light source to the first convex lens to collimate the light beam onto the sample solution.
In another embodiment of the present invention, the sample holder holds a transparent reaction vessel containing the sample solution, in place within the optical path of the light beam for continuous monitoring.
In another embodiment of the present invention, the hot plate stirrer provides uniform heating and stirring with at least one magnetic bead present in the sample solution, to ensure homogeneous conditions during the monitoring of the chemical reaction.
In another embodiment of the present invention, the second convex lens re-collimates the light transmitted or scattered by the sample solution to maintain the integrity of the light beam before focusing.
In another embodiment of the present invention, the objective lens focuses the re-collimated light into the output optical fiber to maximize the intensity of re-collimated light.
In another embodiment of the present invention, the output optical fiber transmits the focused light to the spectrometer to measure the spectra in real-time at nanosecond intervals.
For better understanding, one or more embodiments of the present invention shall be described with respect to the earlier-mentioned drawings.
Referring to Fig. 1, provides the ray diagram of real-time optical apparatus. The optical apparatus depicted in Figure 1 shows the ray diagram of the UV-Vis system. The light from the light source (1) is transmitted through an optical fiber (2) connected to an optical fiber holder (3), which aligns the fiber for optimal light transmission path. A convex lens (4) is placed in the path to collimate the diverging light into a straight beam before it interacts with the sample (5) placed on the hot plate. After passing through the sample, the transmitted light is again collimated by another convex lens (6). The objective lens (7) then focuses the light into a small spot, directing it toward another optical fiber holder (8), which channels the light through an optical fiber (9) to the spectrometer (10) for spectral analysis.
Figure 1(a) relates to schematics of real-time optical apparatus. Figure 1(a) shows the alignment of the optical components around the stirring hot plate. The light source (1) is connected to the system via optical fiber (2), and the system's optical path is shown, from the light entering the apparatus, passing through lenses, interacting with the sample, and being collected by the spectrometer. The alignment ensures accurate measurement of the light absorbed by the sample in real-time.
Figure 1(b) relates to top and side view of the optical apparatus. Figure 1(b), shows the spatial arrangement of the light source, lenses, sample, and collection fiber. The optical fiber holder (3), lenses, and objective lens are aligned in a straight path, with the hot plate stirrer placed in the middle to heat and stir the sample. The apparatus is compact and designed for efficient collection of spectral data while the reaction proceeds on the hot plate. The side view shows how the optical components are positioned vertically around the sample. This view highlights the role of the sample holder (11) in securing the reaction vessel during stirring. The hot plate stirrer (12) is placed below the sample, providing controlled heat and stirring throughout the reaction process. The optical path, shown side-on, illustrates the light beam's interaction with the sample and collection after transmission.
The material and dimension above are given as example without restricting scope of the invention to the same. Thus, other materials and dimension readily apparent to a person skilled in the art are understood to be within purview of the invention.
WORKING OF INVENTION
The present disclosure provides an optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution. The present said apparatus is based on Beer-Lambert's law, which describes the linear relationship between absorbance and the concentration of absorbing species in a medium. This law is applied to monitor real-time changes in a chemical reaction as it proceeds under controlled conditions, such as heating and stirring. The system enables continuous observation of optical properties like absorbance, providing key insights into reaction kinetics, particle size, shape evolution, and concentration changes of reactants and products during chemical processes.
The apparatus provides with a light source (1), which can be a white tungsten filament lamp for visible light or a UV lamp for ultraviolet light, depending on the reaction's requirements. The light emitted is transmitted through an optical fiber (2) and then collimated by a convex lens (4) into a straight, parallel beam. This collimated light beam is directed to the reaction sample, which is typically housed in a container placed on a hot plate stirrer (12). The reaction vessel, held in position by a sample holder (11), ensures the sample remains aligned with the optical path while undergoing heating and stirring. The stirring helps maintain uniform distribution of the reactants, while the hot plate heats the sample to a desired temperature to facilitate the reaction.
As the light passes through the sample, it interacts with the molecules or nanoparticles in the reaction mixture, leading to absorption at specific wavelengths based on the concentration and nature of the absorbing species. According to Beer-Lambert's law, the absorbance (A) of light is proportional to the concentration (c) of the species, the path length (l) of light through the sample, and the molar absorptivity (ε) of the species:
Absorbance (A)= log10(I_0/I) = εlc
Where,
I0 = Incident light intensity
I = Transmitted light intensity
l = Path length
c = molar concentration of solution
ε = molar absorptivity
As the reaction progresses, changes in the optical properties of the sample such as shifts in color or changes in concentration are captured in real time. The transmitted light, which has interacted with the sample, is then collimated by a second convex lens (6) and further focused by an objective lens (7) to form a small, precise spot. The transmitted light is then collected by another optical fiber (9), which directs the light to the spectrometer (10) for analysis.
The spectrometer measures the intensity of the transmitted light across various wavelengths and compares it to the incident light intensity. By calculating the ratio of the two intensities, the spectrometer derives the absorbance values at each wavelength. The apparatus continuously records the absorbance spectrum, which reflects key properties of the reaction, such as particle size distribution, concentration changes, and color shifts. This real-time data helps track dynamic processes such as nanoparticle growth, reactant consumption, and product formation.
For an example, during the synthesis of nanoparticles, the apparatus can monitor the longitudinal plasmon resonance peak, which shifts as the particle size and shape change. As the reaction progresses, the peak may shift from 570 nm to 730 nm, indicating the growth of gold Nano bipyramids (AuNBPs). By observing these peak shifts, the system provides crucial information on how the particles are forming and growing in real-time, enabling precise control over the synthesis process.
In another example, the apparatus can monitor color changes in pH-sensitive reactions. For instance, when NaOH is added to a bromophenol blue solution, the solution changes color from yellow to blue, corresponding to a change in pH. The apparatus captures this color change by recording absorbance shifts at specific wavelengths, enabling quantification of pH changes with high precision.
The apparatus's ability to continuously collect spectra during a reaction, without the need to stop or disturb the process, is a novel feature. Unlike conventional systems that require manual sampling or aliquot removal, this apparatus provides uninterrupted, real-time monitoring. The integration of the hot plate stirrer ensures that the reaction proceeds under optimal mixing and heating conditions, further enhancing the system's ability to capture dynamic changes in the reaction as it happens.
The present invention provides the optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution offers a unique and powerful tool for studying chemical reactions, particularly those involving nanoparticle synthesis, concentration monitoring, or colorimetric changes. By combining optical components like lenses and fibers with precise temperature and stirring control, the apparatus enables researchers to observe the evolution of reactions continuously, providing detailed insights into the reaction dynamics and allowing for more accurate analysis of key parameters such as particle size, shape, concentration, and chemical composition. This capability significantly advances the understanding and control of complex chemical and physical processes.
TECHNICAL ADVANTAGES
With the help of the solution as proposed herein in the context of the present disclosure, the apparatus is highly effective for real-time monitoring of changes in a chemical reaction, especially with regard to changes in the shape and size of particles, color variations due to chemical additions, and shifts in pH. As the reaction proceeds, changes in the optical spectrum can be directly correlated to changes in the shape of nanoparticles or other analytes present in the reaction. For instance, the longitudinal plasmon resonance peak of gold Nano bipyramids (AuNBPs) is known to shift as the shape and size of the particles evolve during synthesis. By continuously recording the absorbance spectrum, the apparatus allows for real-time observation of these shifts, enabling precise monitoring of particle growth dynamics.
During the synthesis of AuNBPs, the apparatus shows a longitudinal spectral shift from 570 nm to 730 nm, with an additional peak appearing around 530 nm. This longitudinal peak shift is directly related to the growth of the Nano bipyramid particles. The apparatus captures real-time changes in the absorption spectrum, providing insight into the reaction conditions required for optimal particle growth. The spectral shift data can also reveal the effects of variations in parameters such as chemical concentration, reaction volume, or temperature on the synthesis process. By analyzing the nature and progression of peak shifts, researchers can better understand the relationship between synthesis conditions and particle morphology. Additionally, the apparatus enables time-dependent studies, tracking the evolution of spectral peaks as a function of reaction time, which further illuminates the dynamics of nanoparticle formation and growth.
The Figure 2 provides visual evidence of these changes, where Figure 2(a) illustrates a wavelength vs. time surface plot showing two major spectral shifts, and Figure 2(b) presents an absorption vs. wavelength plot, clearly showing the longitudinal peak shift from 570 nm to 730 nm during the synthesis process. This visual data provides valuable insights into the nanoparticle synthesis process, highlighting the significant spectral shifts that correspond to changes in particle size and shape.
In another example, the apparatus was used to observe spectral changes during a heating process while stirring a solution. Here, the longitudinal spectrum shifted from approximately 750 nm to 675 nm as heat was applied to the sample at 90°C and 300 rpm for a duration of 4 hours. This study is crucial for determining the precise time and temperature conditions required to produce gold Nano bipyramids with a specific particle size and resonance properties. The ability to monitor these shifts in real time allows for fine-tuning of reaction parameters, ensuring that the desired particle size and optical properties are achieved.
The Figure 3(a) presents a wavelength vs. time surface plot showing two major spectral shifts during the heating process, and Figure 3(b) illustrates the absorption vs. wavelength plot, clearly depicting the longitudinal peak shift from 750 nm to 675 nm over the course of the heating procedure. This data highlights the system's ability to capture dynamic spectral shifts in response to external stimuli such as heat and stirring.
The optical apparatus is also capable of monitoring color changes in pH-sensitive reactions. For example, when NaOH is added to an acidic solution of bromophenol blue, the solution undergoes a color change from yellow to blue, which corresponds to a shift in pH. Although the peak positions in the spectrum remain largely unchanged, the absorbance values shift in response to the color change. By analyzing the absorbance values at specific wavelengths, the system can precisely quantify the amount of acid or base required to trigger the color change in the pH indicator. This feature is particularly useful in pH-dependent reactions where color changes signify chemical transformations.
In the Figure 4(a) presents a wavelength vs. time surface plot showing a significant peak value change in the 600 nm region, and Figure 4(b) shows the absorption vs. wavelength plot, which highlights peak value changes in both the 450 nm and 600 nm regions. This data illustrates how the apparatus can track color changes and absorbance shifts in real time, providing precise information on the pH and chemical composition of the solution during the reaction.
The present apparatus provides a powerful and versatile tool for real-time monitoring of chemical reactions, particularly for nanoparticle synthesis and pH-dependent reactions. By continuously capturing absorption spectra, the system enables researchers to observe dynamic changes in particle size, shape, concentration, and color, providing valuable insights into the reaction kinetics and conditions required for optimal results. The ability to correlate spectral shifts with changes in reaction parameters makes this system a novel and indispensable tool for studying complex chemical processes.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation, no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to disclosures containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. Also, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general, such construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general, such construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."
It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present disclosure contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the disclosure, and other dimensions or geometries are possible. Also, while a feature of the present disclosure may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present disclosure. The present disclosure also encompasses intermediate and end products resulting from the practice of the methods herein. The use of "comprising" or "including" also contemplates embodiments that "consist essentially of" or "consist of" the recited feature.
Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to "at least one of A, B and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B".
The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims:WE CLAIM:

1. An optical apparatus for real-time monitoring of an ongoing chemical reaction in a sample solution, the optical apparatus comprising:
a) a light source (1) for generating a light beam;
b) an input optical fiber (2) adapted for receiving the light beam from the light source, at one end and transmitting it towards another end, wherein the input optical fiber is optically aligned with the light source;
c) a first convex lens (4) aligned with the input optical fiber and adapted for collimating the light beam, received from another end of the input optical fiber, to a parallel beam of light;
d) a sample holder (11) adapted for holding the sample solution to be monitored, in a path of the collimated beam of light;
e) a hot plate stirrer (12) beneath the sample holder adapted for heating and stirring the sample solution during the ongoing chemical reaction;
f) a second convex lens (6) positioned after the sample solution for re-collimating a transmitted and scattered light, after passing through the chemical reaction in the sample solution;
g) an objective lens (7) positioned after the second convex lens and adapted for focusing the re-collimated light;
h) an output optical fiber (9) aligned to the objective lens and adapted for receiving the re-collimated light at one end and transmitting it towards another end of the fiber; and
i) a spectrometer (10) coupled to another end of the output optical fiber and configured for collecting the re-collimated light and generating spectra from the collected re-collimated light,
wherein the generated spectra is analyzed for real-time monitoring of the ongoing chemical reaction in the sample solution.
2. The optical apparatus as claimed in Claim 1, wherein the spectra is analyzed to determine absorbance and transmittance of the sample solution to identify the colour change during the ongoing chemical reaction.
3. The optical apparatus as claimed in Claim 2, wherein the absorbance of the sample solution is determined by measuring an intensity of the spectra at each wavelength, followed by measuring a logarithmic ratio of the intensity.
4. The optical apparatus as claimed in Claim 3, wherein a presence of a plurality of particles of a predefined shape in the sample solution is determined based on one or more peaks of the absorbance, wherein an absorbance peak position gives an absorbance resonance in transverse and longitudinal direction of the particle shape and a peak intensity defines a particle concentration.
5. The optical apparatus as claimed in Claim 3, wherein a presence of different size particles of a predefined shape in the sample solution is determined based on one or more peaks of the absorbance, wherein an absorbance peak position at a higher wavelength is for bigger size particles and the absorbance peak position at lower wavelength is for smaller size particles, and a peak intensity defines the particle concentration.
6. The optical apparatus as claimed in Claim 1, wherein the spectrometer is configured to collect real-time UV-Vis spectra while the sample solution is heated and stirred, for continuous monitoring of a nanoparticle synthesis and recording color change spectrum due to addition of different chemicals during the ongoing chemical reaction.
7. The optical apparatus as claimed in Claim 5, wherein the pH of ongoing chemical reaction is determined by studying the color change spectrum of the pH indicator present in the solution.
8. The optical device as claimed in Claim 1, wherein the light source is a tungsten filament or a UV lamp.
9. The optical apparatus as claimed in Claim 1, wherein the input optical fiber is configured to direct the light from the light source to the first convex lens to collimate the light beam onto the sample solution.
10. The optical apparatus as claimed in Claim 1, wherein the sample holder holds a transparent reaction vessel containing the sample solution, in place within the optical path of the light beam for continuous monitoring.
11. The optical apparatus as claimed in Claim 1, wherein the hot plate stirrer provides uniform heating and stirring with at least one magnetic bead present in the sample solution, to ensure homogeneous conditions during the monitoring of the chemical reaction.
12. The optical apparatus as claimed in Claim 1, wherein the second convex lens re-collimates the light transmitted or scattered by the sample solution to maintain the integrity of the light beam before focusing.
13. The optical apparatus as claimed in Claim 1, wherein the objective lens focuses the re-collimated light into the output optical fiber to maximize the intensity of re-collimated light.
14. The optical apparatus as claimed in Claim 1, wherein the output optical fiber transmits the focused light to the spectrometer to measure the spectra in real-time at nanosecond intervals.

Dated this 4th day of November, 2024

[SONAL MISHRA]
-DIGITALLY SIGNED-
IN/PA-3929
OF L.S. DAVAR & CO.
ATTORNEY FOR THE APPLICANT(S)

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