Emission Phenomena Research Articles

Surface denitration structure on dynamic combustion performance and muzzle flame of mixed nitrate gun propellant

AbstractThe gun propellant is an inaccessible energy and fuel for projectile to achieve destructive capability in a weapon system. Nitrocellulose/nitroglycerine/triethylene glycol dinitrate(NC/NG/TEGDN) based gun propellant with higher energy level than single‐based gun propellant can meet the demands of modern warfare. Currently, deterring strategy is commonly used to improve the combustion progressivity of NC/NG/TEGDN based gun propellant, together with aggravating the harmful emission phenomena such as muzzle smoke and flame. Therefore, it is essential to design and fabricate NC/NG/TEGDN based gun propellant with both good combustion progressivity and low characteristic signal. In this work, a gradiently denitrated NC/NG/TEGDN based gun propellant was successfully prepared by denitration strategy, whose structure was confirmed by FT‐IR, Raman and SEM. Here, closed bomb vessel test and interior ballistic test were conducted. The results showed that the gradiently denitrated NC/NG/TEGDN based gun propellant exhibited better combustion progressivity and interior ballistic performance than raw gun propellant, and these properties can be controlled by modulating the degree of denitration. Meanwhile, the change laws of the muzzle smoke and flame of the gradiently denitrated NC/NG/TEGDN based gun propellant were investigated by the smoke box method and high‐speed photography. Furthermore, a lower characteristic signal for the gradiently denitrated NC/NG/TEGDN based gun propellant was found compared to the deterred gun propellant by theoretical calculations. This work provides a new idea for preparing and applying a gun propellant with excellent comprehensive performance, including high energy, good combustion progressivity and low characteristic signal.

Investigation of the Relationship between Electronic Structures and Bioactivities of Polypyridyl Ru(II) Complexes.

Ruthenium (Ru)-based organometallic drugs have gained attention as chemotherapeutic and bioimaging agents due to their fewer side effects and excellent physical optical properties. Tuning the electronic structures of Ru complexes has been proven to increase the cytotoxicity of cancer cells and the luminescent efficiency of the analytical probes. However, the relationship between electronic structures and bioactivities is still unclear due to the potential enhancement of both electron donor and acceptor properties. Thus, we investigated the relationship between the electronic structures of Ru(II) complexes and cytotoxicity by optimizing the electron-withdrawing (complex 1), electron-neutral (complex 2), and electron-donating (complex 3) ligands through DFT calculations, bioactivities tests, and docking studies. Our results indicated that it was not sufficient to consider only either the effect of electron-withdrawing or electron-donating effects on biological activities instead of the total electronic effects. Furthermore, these complexes with electron-donating substituents (complex 3) featured unique "off-on" luminescent emission phenomena caused by the various "HOMO-LUMO" distributions when they interacted with DNA, while complex with electron-withdrawing substituent showed an "always-on" signature. These findings offer valuable insight into the development of bifunctional chemotherapeutic agents along with bioimaging ability.

One-Dimensional Organic-Inorganic Lead Bromide Hybrids with Excitation-Dependent White-Light Emission Templated by Pyridinium Derivatives.

Organic-inorganic hybrid metal halides have attracted widespread attention due to their excellent tunability and versatility. Here, we have selected pyridinium derivatives with different substituent groups or substitution positions as the organic templating cations and obtained six 1D chain-like structures. They are divided into three types: type I (single chain), type II (double chain), and type III (triple chain), with tunable optical band gaps and emission properties. Among them, only (2,4-LD)PbBr3 (2,4-LD = 2,4-lutidine) shows an exciton-dependent emission phenomenon, ranging from strong yellow-white to weak red-white light. By comparing its photoluminescence spectrum with that of its bromate (2,4-LD)Br, it is found that the strong yellow-white emission at 534 nm mainly came from the organic component. Furthermore, through a comparison of the fluorescence spectra and lifetimes of (2,4-LD)PbBr3 and (2-MP)PbBr3 (2-MP = 2-methylpyridine) with similar structures at different temperatures, we confirm that the tunable emission of (2,4-LD)PbBr3 comes from different photoluminescent sources corresponding to organic cations and self-trapped excitons. Density functional theory calculations further reveal that (2,4-LD)PbBr3 has a stronger interaction between organic and inorganic components compared to (2-MP)PbBr3. This work highlights the importance of organic templating cations in hybrid metal halides and the new functionalities associated with them.

Exploring the Individual Pulse Behavior of Pulsar J1701−3726 with Parkes

We have carried out a detailed study of polarimetric individual pulse emission from the pulsar J1701−3726 (B1658−37), observed at 1369 MHz using the Parkes 64 m radio telescope. The single-pulse sequences reveal the presence of the three major emission phenomena of pulse nulling, mode changing, and subpulse drifting. Trimodal distribution of the pulse energy is present, implying one population of nulls and two others of emission in the phase window. The mean flux density of the normal mode is almost two times that of the abnormal mode. Our data show that, for PSR J1701−3726, 64% of the time was spent in the normal mode and 12% was in the abnormal mode. The single pulses show the presence of two distinct periodic modulations using a fluctuation spectral analysis. About 24% of the nulls are found to create alternating bunches of nulls and bursts in a quasiperiodic manner with a longer periodicity of 48 ± 4 rotational periods. Additionally, the pulsar presents a steady even–odd modulated feature with a stationary longitude within the pulse window. The ramifications for constraining the viewing geometry and understanding the radio emission mechanisms are discussed.

Regulating donor-acceptor system toward highly efficient dual-state emission for sensitive response of nitroaromatic explosives

Dual-state emission luminogens (DSEgens) as fluorophores emit efficiently in solution and solid forms have gained increasing concern in the field of chemical sensing. Recent efforts by our group led to the identification of DSEgens as an easy-to-visualize nitroaromatic explosives (NAEs) detection platform. However, none of the previously studied NAEs probes show effective improvement in sensitivity. Here, we designed a series of benzoxazole-based DSEgens through multiple strategies driven by theoretical calculations, revealing their improved detecting performance on NAEs. Compounds 4a-4e exhibit thermal- and photo-stability, large Stokes shift as well as sensitivity solvatochromism (except for 4a and 4b). A subtle balance between rigid conjugation and distorted conformation endows these D-A type fluorophores 4a-4e with DSE properties. Furthermore, 4d and 4e show aggregation-induced emission phenomenon caused by distorted molecular conformation and restricted intramolecular rotation. Interestingly, DSEgen 4e displays anti-interference and sensitivity towards NAEs with a detection limit of 10-8 M. It can be applied for expedient and distinct visual identification of NAEs not only in solution but also on filter paper and film, supporting this new DSEgen as reliable NAEs chemoprobe.

Radiation and Emission Phenomena in Combination

Radiation and Emission Phenomena in Combination

Effects of un-parallel notches on the granite fracture properties and acoustic emission phenomena under biaxial test: PFC computation and experimental verification

To assess connections between these notches throughout fracture formation under stress, the mechanical performance of granite specimens with two non-parallel notches underwent a biaxial compression test. The first notch had a 45° angle, whereas the second had a variable angle (0°, 45°, 90°, 130°, and 180°). Three ligament angles (0°, 45°, and 90°) were measured between the inner tips of two notches and the horizontal axis. The ligament length, distance between the inner tips of the two notches, and both notch lengths were each 2 cm. These samples were examined at 0, 1, and 3 MPa confining pressures. By using the particle flow code (PFC), simulated results of the evaluations were run after the trials. It was discovered that the specimens’ failure strengths were influenced by the notch’s geometric characteristics, which in turn impacted the failure mechanism as well as fracture geometry. The number of tensile fractures had an impact on the specimens’ failure strengths. Whilst also increasing the ligament angle, more induced tensile cracks were produced. In the early stages of loading, just a few AE events were found, but after that, they multiplied quickly before approaching the peak stress. By raising the confining pressure, the AE hits were increased and delay failure was occured. The failure strength and AE hits are significantly impacted by the second notch’s angle. In constant ligament angel, the compressive strength of models containing overlapped joint were more than that with non-overlapped joints. In models containing non-overlapped notches, the model with ligament angles of 0° and 45° had maximum and minimum compressive strength, respectively. In models containing overlapped notches, the model with ligament angles of 90° and 45° had maximum compressive strength and minimum compressive strength, respectively. In all ligament angles, minimum compressive strength was occurred when the upper joint angle was 45°. Both the computational and experimental methodologies showed that the specimens’ failure pattern and compressive strength were very comparable.

Hetero-Aggregation-Induced Tunable Emission in Multicomponent Crystals

Crystal engineering is a green and convenient approach to designing desirable materials through rational manipulation of intermolecular interactions. We have reported the lesser reported sulfonate–pyridinium intermolecular interaction for the design and synthesis of organic co-crystals with improved features. Here in we report the utilization of the interaction to tune the solid-state luminescence of organic precursor naphthalene disulfonic acid (NDSA-2H). Organic salts of NDSA-2H are synthesized and characterized with three isostructural bipyridyl co-formers: 4-phenylpyridine (4-PhPy), 2-phenylpyridine (2-PhPy) and 2,2′-bipyridine (2,2-bpy). Structural investigation validates aggregation of organic acid and base co-formers through sulfonate–pyridinium synthon and proton transfer between them. Compared to NDSA-2H, the molecular salts [(4-PhPy-H)2+(NDSA)2–·2H2O] (1) and [(2,2-BPY-2H)2+(NDSA)2–] (3) undergo a blue and red shift, respectively, while solid-state emission of [(2-PhPy-H)2+(NDSA)2–] (2) remains unaltered. This solid-state emission tuning is attributed to the different modes of crystal packing and arises from monomer emissions in 1 and 2 and excimer emission in 3. 3 also exhibits a relatively longer lifetime of 20.7 ns while 2 exhibits better quantum yields (ϕ = 22.7). Solution-phase photophysical behavior has been investigated for representative co-crystal system 3, after validation of its solution-phase integrity. 3 undergoes a hetero-aggregation-induced tunable emission (HAITE) phenomenon in the water–acetone system to exhibit maximum emission intensity at 90% volume fraction of acetone, which is further validated by the diffuse light scattering (DLS) and scanning electron microscopy (SEM) studies. 3 also exhibits solvatochromism in terms of emission intensity change with the nature of the solvent, being brightest in methanol (ϕ = 29.3) and very dim in water (ϕ = 10.1).

Accuracy enhancement of laser-induced breakdown spectroscopy by polarization spectrum fusion

Laser-induced breakdown spectroscopy (LIBS) has been proven to be an effective way for online analysis of coal properties (such as ash content, volatile content, and calorific value), but the quantitative analysis accuracy still needs to be improved. Herein, a polarization spectral data fusion scheme was proposed to obtain more abundant spectral information and improve the performance of quantitative analysis models. First, the polarization effect of laser-induced coal plasma emission was analyzed using the Stokes parameters of the average spectra. Due to the partially polarized phenomenon of emission, fused data of PRLIBS (0°, 0) (horizontal plasma polarization spectra) and PRLIBS (90°, 0) (vertical plasma polarization spectra) was utilized to establish an efficient prediction model to obtain high prediction accuracy. For fusion models, the root mean square error prediction (RMSEP) of ash content, volatile content and calorific values were 1.497%, 0.595%, and 0.597%, respectively, and the coefficients of determination (R2) were 0.980, 0.968, and 0.978, respectively. Comparison with regression models for individual PRLIBS (0°, 0), PRLIBS (90°, 0), and LIBS data, the data fusion scheme significantly improved the performance of the prediction model. The improvement in model performance is due to the fact that there is no perfect correlation between PRLIBS (0°, 0) and PRLIBS (90°, 0), whilst polarization spectral fusion makes it possible to acquire more number of characteristic spectral lines with high importance score. The results demonstrated the feasibility of PRLIBS spectral fusion to provide better analytical results for ash content, volatile content, and calorific values of coal.

Investigation on Thermal Efficiency Enhancement and Sideband Emission Suppression for Magnetron Injection Gun

At low-power operation, an approach with a capture structure is employed to absorb the trapped electrons for the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{Ka}$</tex-math> </inline-formula> -band gyro-traveling wave tube (Gyro-TWT). When the power is further increased, the capture structure cannot play a role and the working current fluctuates. In subsequent experiments, the capture structure was found to have severe traces of melting. According to the position characteristics of the capture structure, the main reason for its melting is the phenomenon of sideband emission from the cathode of magnetron injection gun (MIG). In heat transfer systems of the conventional cathode, the rear electrode emits trapped electrons, which are accelerated by an electric field and bombard the capture structure. We adopted the scheme of adjusting the cathode heat transfer system. The enhanced cathode is called the isolated cathode (ISO-cathode). The test experiment proved that sideband emission is suppressed and thermal efficiency is improved. In the experiment, the cathode power decreased from 85 to 42 W when the operating temperature is at 1050 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> C. In the end, the absorbed power of the capture structure is less than about 1/10 of the original power by simulation. The life and reliability of MIG are increased by ISO-cathode. The foundation is laid for further improvement on the average power by ISO-cathode.

Pyronin Derivatives as Efficient Electrochemiluminescence Emitters in Aqueous Solution

The electrochemiluminescence (ECL) behavior of pyronin derivatives was reported. We found that these derivatives, as novel ECL emitters, generated an efficient emission phenomenon; that is, they showed anodic emission using tri-propylamine (TPA) as the coreactant and cathodic ECL emission using K2S2O8 as the coreactant. Because of its remarkable luminescent performance, the ECL mechanism (reductive-oxidative and oxidative-reductive) of benzylthiol-substituted pyronin (BTP) was specifically studied. Surprisingly, the cathodic ECL emission of BTP had a lower ECL peak potential at −0.54 V (vs. SCE) in aqueous solution. The potential range of −0.7 V to 0.0 V is lower than that of previously reported K2S2O8 cathodic ECL systems. Its good water solubility, easy modification, and excellent emission properties facilitate appealing (bio)analytical applications in ECL biosensors and cell imaging.

Tetraphenylethene-based macrocycles: Visualized monitoring the hydrolysis of silicon-oxygen bond and their tunable luminescent properties

The preparation of silicone material is generally carried out by hydrolytic condensation, and various methods have been tried so far to study the kinetics of silicon-oxygen bond hydrolysis. However, the process and kinetics of silicon-oxygen bond hydrolysis cannot be efficiently monitored in real-time due to the limitations of traditional testing methods. In the present study, we have successfully designed and synthesized a series of circular tetraphenylethylene (TPE) derivatives connected with different lengths of the siloxanes chain. As the chain length gets longer, the restriction on phenyl rotation in TPE derivatives becomes weaker, which induced fluorescence quenching gradually at the molecular level. Hence, it provides the most direct and convincing evidence for the effect of chain lengths in the popular restricted intramolecular rotation (RIR) mechanism with aggregation-induced emission (AIE) phenomenon. The strong fluorescent molecule was used to monitor the kinetics of silicon-oxygen bond hydrolysis in real-time successfully by the AIE method with the RIR mechanism. The high sensitivity and efficiency of fluorescence provide an unparalleled “visualization” window for real-time monitoring of the kinetic control of Si-O bond hydrolysis. Furthermore, the half-life and reaction kinetic data of Si-O bond-breaking reaction by different pH are obtained to provide a reference for scientists and engineers not only in fundamental research but also in industrial production. Finally, the aggregation-induced color-tunable emission was obtained with the different aggregation forms of molecules, exhibiting a promising potential for intelligent luminescent materials.

Mechanism analysis of field electron emission of titanium

Field electron emission (FEE) is generally considered to be closely correlated with radio frequency (RF) breakdown in accelerating structures and high-power microwave (HPM) devices. In this study, the field emission characteristics of titanium are investigated by using a field emission test system. With the increase of the number of field emission tests and stability tests, the repeatability of the field emission characteristic curve of titanium tends to be better, and the amplitude of the current oscillation in the stability tests gradually decreases, indicating that the field emission performance of titanium gradually becomes stable. Subsequently, the field emission characteristic curve of titanium is analyzed by adopting the field emission theory of metal microprotrusions. Combined with the analysis of the electric field enhancement effects caused by the surface morphology, the dominant effect of the metal microprotrusions on the FEE of titanium is excluded from the two aspects of the electric field enhancement factor and local maximum emission current density. At last, the field emission theory of dielectric micropoints is introduced to analyze the field emission characteristics of titanium. The electric field enhancement factor of 102 ∼ 103 are explained theoretically. Simultaneously, the reasonable effective emission area and local emission current density are given, which can better explain the field emission phenomena of titanium, such as the sharp decrease in emission current and repeatability of the field emission curve. Hence, it is revealed that the key factor that dominates the FEE of titanium is the dielectric impurities on the surface, rather than the metal microprotrusions.

Recent advances in room temperature phosphorescence of chiral organic materials.

Room temperature phosphorescence (RTP) in purely organic materials is an uncommon phenomenon of emission, which can be characterized by a long persistent luminescence after removal of the excitation source. In the recent years, RTP organic materials have received a considerable attention due to their high application potential in various advancing technologies, ranging from optoelectronic to biomedical applications. In parallel, many progresses have been achieved on the rationalization of this process and led to the emergence of innovative strategies aiming to achieve highest performances both in terms of phosphorescence efficiency and lifetime. While the topic is still on an ascendant development, the generation of circularly polarized phosphorescent (CPP) emission from purely organic molecules is by far much less explored and remains an impressive challenge. Still, the perspective of CPP materials appears as an interesting opportunity to answer several comprehensives issues existing in the field. In this article, we define, in a straightforward way, basic principles and key notions for the generation of RTP and CPluminescence (CPL) guiding the design toward CPP materials. After this brief insight, recent advances in the field of chiral organic RTP materials are discussed with an emphasis on their CP-RTP properties. Based on this development, the conclusion drawn allows establishing the next challenges and future opportunities standing in the field.

Infrared-to-visible conversion in strontium sulphate through a defect-based infrared stimulated visible emission phenomenon.

Strontium sulphate (SrSO4 ) is a defect-based photoluminescence material, generally used in thermoluminescence applications, and has been studied for infrared (IR) stimulated visible emission. The SrSO4 particles were synthesized using a precipitation method. The orthorhombic phase of SrSO4 was confirmed from the X-ray diffraction pattern and the formation of micron-sized particles was authenticated from field emission scanning electron micrographs. The elemental composition of oxygen and strontium was determined using energy-dispersive X-ray analysis measurement that confirmed the presence of and intrinsic defects in the material. Photoluminescence investigations showed the presence of various defect bands in the band gap giving rise to intrinsic luminescence in SrSO4 . The emission in the visible region was attributed to the defect band arising due to . Photoluminescence lifetime measurement confirmed the presence of stable defect states with a lifetime in microseconds. The SrSO4 sample was tested using IR lasers and a red-orange emission spot was observed from the powder sample when excited with IR lasers. The underlying principle for IR-to-visible conversion in the material is a defect-mediated phenomenon that has been described through the energy level diagram of the material.

Effect of bulky side groups on photophysical properties and electroluminescent performance of oligo(styryl)benzenes

The rational design of electroluminescent compounds has been recognized as a promising strategy to maximize the efficiency of electronic devices. In this work, we analyze the impact of the substitution of n-alkyl and n-alkoxy side chains by bulkier side groups (tert-butyl and tert-butoxy) on the photophysics of the two model fluorophores 1,3,5-tris(styryl)benzene and 1,2,4,5-tetra(styryl)benzene. We found that the bulky side groups have a significant contribution to the vibrational normal modes associated with the non-radiative deactivation. The aggregation-induced enhanced emission phenomenon observed in some cases was attributed to the blocking of the trans→cis photoisomerization and the restriction of intramolecular vibrations. In the solid state, the bulky side groups have demonstrated to play a determining role in the supramolecular structure and photophysical properties, particularly in the case of the tetra(styryl)benzenes. In light-emitting devices, we found that the incorporation of the bulky side groups in oligo(styryl)benzenes could reduce the electromer formation and improve the device performance. The tetra(styryl)benzenes, and particularly the tert-butyl derivative, showed better device performance, with lower turn-on voltage, higher current density and electroluminescent intensity.

Paper-based device for nanomolar detection of Cd2+ using AIEE-active imidazolium ionic liquid functionalized phenothiazine based Schiff-Base

A highly green fluorescent phenothiazine-based imidazolium ionic liquid (IL) [PTZ-SB][Br] was synthesized and its structure was thoroughly elucidated by 1H, 13C NMR, FT-IR, UV–visible spectroscopy and Mass spectrometry. Furthermore, thermal resilience of the IL was established by TGA and DSC investigations. The novel molecule revealed a distinct recognition for Cd2+ ions over eleven other transition metal ions. Moreover, the promising results obtained in the solution phase interested us to embed [PTZ-SB][Br] on paper strips to create a paper-based fluorescent sensor, which was examined by a portable UV light source for the on-site Cd2+ detection. Interestingly, the device demonstrated exceptional fluorescence sensing behavior towards Cd2+ with a limit of detection (LOD) of 0.16 nM. Thus, the probe has noteworthy distinct and sensitive detection ability towards Cd2+, which might find practical and on-spot applications. Noticeably, [PTZ-SB][Br] demonstrated aggregation-induced enhanced emission (AIEE) phenomenon. In fact, an incredible 38.1-fold increase in fluorescence intensity was observed for 10:90 ratio of THF:water mixture as compared that for pure THF solution of [PTZ-SB][Br]. AIEE property was further supported by DLS studies. A paper-based device for Cd2+ sensing by applying an Ionic Liquid based Schiff base is reported herein for the first time.

Anthracene scaffold as highly selective chemosensor for Al3+ and its AIEE activity.

Fluorescent chemosensor, 3-(Anthracen-2-yliminomethyl)-benzene-1,2-diol (ANB) has been synthesized by one-step condensation of 2-aminoanthracene and 2,3-dihydroxybenzaldehyde and characterized using 1H-NMR, FT-IR and Mass spectroscopic techniques. The probe ANB was found to be an efficient 'turn-on' fluorescence chemosensor for the selective detection of Al3+ ion over other metal ions in an aqueous solution. The chemosensor exhibits ~ 27-fold enhancement of emission intensity in presence of Al3+ ion. Fluorescence quantum values for ANB and (Al3+-ANB)-complex are 0.004 and 0.097, respectively. In addition, the binding constant and the limit of detection were found to be 1.22 × 104M-1 and 0.391µM, respectively. The chemosensor ANB binds to Al3+ ions in 2:1 stoichiometric ratio which was supported by Job's plot, 1H-NMR titration and florescence titration. Fluorescence reversibility of the sensor complex was well established by adding EDTA in the same condition and a molecular INHIBIT logic gate was fabricated using this reversible nature of the sensor complex. Additionally, the chemosensor ANB shows a novel aggregation-induced enhanced emission phenomenon, where the aggregate hydrosol of ANB shows enhance emission intensity.

A dπ‐pπ Conjugated System with High Mobility and Strong Emission Simultaneously

AbstractStrong intermolecular interactions usually facilitate charge transport, but impede photoluminescence, therefore, the development of organic π‐conjugated materials that exhibit both semiconducting and light‐emissive properties remains challenging. Herein, a series of perylene diimide (PDI)‐based carbolong complexes with dπ‐pπ conjugation is synthesized. The resulting alcohol‐soluble products exhibit broad and strong absorption combined with outstanding electronic and optical properties, and are applied as electron transport layer materials in organic solar cells, achieving power conversion efficiencies up to 17.36%. In addition, these complexes exhibit an uncommon aggregation‐induced emission phenomenon. These results will aid in future design of π‐conjugated materials with increased functionality.

Viking Spectrophotometer: A Home-Built, Simple, and Cost-Efficient Absorption and Fluorescence Spectrophotometer for Education in Chemistry

Investigating the optical properties of various chemical compounds using UV–vis spectrophotometers is an essential part of education in chemistry. However, commercial spectrophotometers are usually treated as “magic black boxes”, where the dominant majority of optical elements are hidden “under the hood”. This often limits understanding of the mechanisms behind the generation of spectral curves, which in turn may impede the ability to understand the limitations of the applied method and, in some cases, interpret the acquired data. In addition, the study of optical emission phenomena using fluorescence spectrophotometers is seldom implemented in educational laboratories due to the practical challenges and costs of the devices, which severely limit pedagogic access to this topic. For students to be more confident with these two basic spectroscopy techniques, we have developed a laboratory kit that provides a multifaceted learning experience. Starting with a basic exploration of an instrument assembly, it teaches, for example, such technical concepts as spectral resolution and detection sensitivity. More fundamentally, it enables deeper learning of the Beer–Lambert law and the notion of Stokes shift. The spectrophotometer is built from cost-efficient materials and is easily scalable, making it affordable for many educational laboratories. Due to a modular design, it is adaptable to various levels of education and has been successfully applied during high school-, undergraduate-, and graduate-level classes.