Tuning of the Topochemical Polymerization of Diacetylenes Based on an Odd/Even Effect of the Peripheral Alkyl Chain: Thermochromic Reversibility in a Thin Film and a Single-Component Ink for a Fountain Pen

Kim, Myeong Jin,Angupillai, Satheshkumar,Min, Kyeongsu,Ramalingam, Manivannan,Son, Young-A. American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.29

<P>The topochemical polymerization of diacetylenes (DAs) is closely related to the length of their alkyl chain. DA monomers have two types of alkyl chain side groups: the inner alkyl chain and the outer alkyl chain, that is, the peripheral alkyl chain. Herein, we designed and synthesized a series of DA monomers that possess bis-amide linkages with different peripheral alkyl chains (<I>n</I> = 6-9; <B>DA1-DA4</B>). The peripheral alkyl chain length of these DA monomers exhibits an odd/even effect on topochemical polymerization. The polymerization of DAs was achieved only when <I>n</I> is an odd number, whereas no polymerization occurred when n is an even number. The odd/even effect on the topochemical polymerization was also investigated using ab initio density functional theory calculations. The thermochromic reversibility of polydiacetylenes (PDAs) was investigated using UV-vis absorption spectroscopy at temperatures ranging from 20 to 60 °C. Monomer <B>DA2</B> was used as a single-component ink solution in a fountain pen that can be transformed into thermochromic letters on conventional paper. Furthermore, a PDA-embedded polyethylene oxide film was included to monitor the thermochromic reversibility and was found to exhibit excellent thermochromic reversibility between 20 and 100 °C and stability, enabling storage for a few months without deformation. Finally, a green-colored patterned polymer film is readily obtained by a subtractive color (blue and yellow) mixing method and exhibits high thermochromic reversibility at temperatures between 20 and 100 °C.</P> [FIG OMISSION]</BR>

A reaction based colorimetric chemosensor for the detection of cyanide ion in aqueous solution

Kim, Ick Jin,Ramalingam, Manivannan,Son, Young-A. Elsevier 2017 Sensors and actuators. B Chemical Vol.246 No.-

<P><B>Abstract</B></P> <P>A conjugated naphthoquinone-benzothiazole (<B>R</B>) system was developed and characterized and its cyanide sensing properties were monitored in 80% aqueous DMF solution. Cyanide ions react with the receptor through a nucleophilic addition reaction, resulting in immediate color change that can be viewed and monitored colorimetrically and fluorimerically. Optical properties of <B>R</B> were not affected by the addition of other common anions in the presence and absence of cyanide ions. A test strip based on <B>R</B> was fabricated and could act as a convenient test kit to detect cyanide ions. Thus, the receptor can be used as an effective probe to detect cyanide ions in aqueous solution.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A naphthoquinone-benzothiazole based chemosensor for the detection of cyanide is described. </LI> <LI> The color of the receptor changed from yellow to colorless with the addition of cyanide ion. </LI> <LI> The mechanism of sensing involves nucleophilic addition of CN<SUP>−</SUP> to the benzothiazole CN bond. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Rhodamine-fluorene based dual channel probe for the detection of Hg2+ ions and its application in digital printing

Min, Kyeong Su,Manivannan, Ramalingam,Son, Young-A Elsevier 2018 Sensors and actuators. B Chemical Vol.261 No.-

<P><B>Abstract</B></P> <P>A new chemosensor based on a fluorene-rhodamine conjugate was designed and synthesized for the selective recognition of Hg<SUP>2+</SUP> ion in 80% aq. DMF. The receptor is highly selective and sensitive towards mercury ions over other metal ions in both normal and UV light. A binding constant on the order of 10<SUP>5</SUP> was calculated using the fluorescence technique, indicating that the receptor strongly bound the mercury ion. The type of binding and the sensing mechanism were confirmed by <SUP>1</SUP>H, <SUP>13</SUP>C NMR and FT-IR spectral studies. The mechanism by which the receptor senses mercury ions is through rhodamine ring opening process. The prepared <B>R</B>/polyurethane electro spun nanofiber could selectively sense Hg<SUP>2+</SUP> ions in the form of a strip. Finally, the synthesized receptor could be used as a digital printing material and showed a good response to sensing mercury in 100% water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A rhodamine-fluorene based receptor senses Hg(II) ion selectively in 80% aq. DMF solution. </LI> <LI> The mechanism of sensing is mediated through bond energy transfer. </LI> <LI> The sensor receptor was printed as a digital printing ink material and showed color change for mercury ion. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis, Photophysical,Electrochemical, Tumor-Imaging,and Phototherapeutic Properties of Purpurinimide-<i>N</i>-substituted Cyanine Dyes Joined with Variable Lengths of Linkers

Williams, MichaelP. A.,Ethirajan, Manivannan,Ohkubo, Kei,Chen, Ping,Pera, Paula,Morgan, Janet,White, William H.,Shibata, Masayuki,Fukuzumi, Shunichi,Kadish, Karl M.,Pandey, Ravindra K. American ChemicalSociety 2011 Bioconjugate chemistry Vol.22 No.11

<P>Purpurinimide methyl esters, bearing variable lengthsof N-substitutions,were conjugated individually to a cyanine dye with a carboxylic acidfunctionality. The results obtained from <I>in vitro</I> and <I>in vivo</I> studies showed a significant impactof the linkers joining the phototherapeutic and fluorescence imagingmoieties. The photosensitizer–fluorophore conjugate with aPEG linker showed the highest uptake in the liver, whereas the conjugatelinked with two carbon units showed excellent tumor-imaging and PDTefficacy at 24 h postinjection. Whole body imaging and biodistributionstudies at variable time points portrayed enhanced fluorescent uptakeof the conjugates in the tumor compared to that in the skin. Interestingly,the conjugate with the shortest linker and the one joining with twocarbon units showed faster clearance from normal organs, e.g., theliver, kidney, spleen, and lung, compared to that in tumors. Bothimaging and PDT efficacy of the conjugates were performed in BALB/cmice bearing Colon26 tumors. Compared to the others, the short linkerconjugate showed poor tumor fluorescent properties and as a corollarydoes not exhibit the dual functionality of the photosensitizer–fluorophoreconjugate. For this reason, it was not evaluated for <I>in vivo</I> PDT efficacy. However, in Colon26 tumor cells (<I>in vitro</I>), the short linker was highly effective. Among the conjugates withvariable linkers, the rate of energy transfer from the purpurinimidemoiety to the cyanine moiety increased with deceasing linker length,as examined by femtosecond laser flash photolysis measurements. Noelectron transfer from the purpurinimide moiety to the singlet excitedstate of the cyanine moiety or from the singlet excited state of thecyanine moiety to the purpurinimide moiety occurred as indicated bya comparison of transient absorption spectra with spectra of the one-electronoxidized and one-electron reduced species of the conjugate obtainedby spectroelectrochemical measurements.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/bcches/2011/bcches.2011.22.issue-11/bc200345p/production/images/medium/bc-2011-00345p_0016.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/bc200345p'>ACS Electronic Supporting Info</A></P>

DEVELOPMENT OF AN IDLE SPEED ENGINE MODEL USING IN-CYLINDER PRESSURE DATA AND AN IDLE SPEED CONTROLLER FOR A SMALL CAPACITY PORT FUEL INJECTED SI ENGINE

P. V. MANIVANNAN,M. SINGAPERUMAL,A. RAMESH 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.1

An idle speed engine model has been proposed and applied for the development of an idle speed controller for a 125 cc two wheeler spark ignition engine. The procedure uses the measured Indicated Mean Effective Pressure (IMEP) at different speeds at a constant fuel rate and throttle position obtained by varying the spark timing. At idling conditions, IMEP corresponds to the friction mean effective pressure. A retardation test was conducted to determine the moment of inertia of the engine. Using these data, a model for simulating the idle speed fluctuations, when there are unknown torque disturbances, was developed. This model was successfully applied to the development of a closed loop idle speed controller based on spark timing. The controller was then implemented on a dSPACE Micro Autobox on the actual engine. The Proportional Derivative Integral (PID) controller parameters obtained from the model were found to match fairly well with the experimental values, indicating the usefulness of the developed idle speed model. Finally, the optimized idle speed control algorithm was embedded in and successfully demonstrated with an in-house built, low cost engine management system (EMS) specifically designed for two-wheeler applications.

Blue LED light enhances growth, phytochemical contents, and antioxidant enzyme activities of Rehmannia glutinosa cultured in vitro

Manivannan, A.,Soundararajan, P.,Halimah, N.,Ko, C. H.,Jeong, B. R. Springer Science + Business Media 2015 Horticulture, Environment, and Biotechnology Vol.56 No.1

A Quinoline carboxamide based Fluorescent Probe’s Efficient Recognition of Aluminium Ion and its Application for Real Time Monitoring

Ramalingam Manivannan,Jiwon Ryu,Young-A Son 한국염색가공학회 2020 韓國染色加工學會誌 Vol.32 No.4

A colorimetric and fluorometric chemosensor for the selective detection of cyanide ion in both the aqueous and solid phase

Kim, Myeong Jin,Manivannan, Ramalingam,Kim, Ick Jin,Son, Young-A. Elsevier Sequoia 2017 Sensors and actuators. B Chemical Vol.253 No.-

<P><B>Abstract</B></P> <P>A new colorimetric and fluorometric chemosensor was developed and synthesized that showed both color and fluorescence changes upon the addition of cyanide ion in 80% aq. DMSO solution and in the solid phase. The chemosensor showed a selective and sensitive response to cyanide ion over other common anions such as F<SUP>−</SUP>, Cl<SUP>−</SUP>, Br<SUP>−</SUP>, I<SUP>−</SUP>, H<SUB>2</SUB>PO<SUB>4</SUB> <SUP>−</SUP>, NO<SUB>3</SUB> <SUP>−</SUP> and AcO<SUP>−</SUP>. The binding stoichiometry between the receptor and cyanide ions was found to be 1:2 ratio, and the detection of cyanide occurred through deprotonation coupled with intermolecular proton transfer, which was confirmed by a <SUP>1</SUP>H NMR titration experiment. The detection limit was calculated to be 7.49nM, which is much lower than the permissible limit set by WHO (1.9μM).</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new fluorene-aminomalenonitrile based receptor for cyanide ion in both aqueous and solid phase. </LI> <LI> The mechanism of sensing involves deprotonation coupled with intermolecular proton transfer. </LI> <LI> The receptor showed color change from yellow to red and also fluorescence turn-on response. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Sources of silicon influence photosystem and redox homeostasis-related proteins during the axillary shoot multiplication of <i>Dianthus caryophyllus</i>

Manivannan, A.,Soundararajan, P.,Cho, Y. S.,Park, J. E.,Jeong, B. R. Informa UK (TaylorFrancis) 2018 Plant biosystems Vol.152 No.4

<P>The present endeavor has demonstrated the impacts of different sources of silicon (Si) such as potassium silicate (K2SiO3) and calcium silicate (CaSiO3) during the in vitro axillary shoot multiplication of carnation. For the Si treatments, nodal explants were cultured onto the Murashige and Skoog's medium fortified with 1.0mgL(-1) of 6-benzyladenine and 0.5mgL(-1) indole-3-acetic acid with or without K2SiO3 and CaSiO3 in three different concentrations (0, 1.8, or 3.6mM). After six weeks, the shoot induction ratio, number of shoots produced per explant, expression of photosystem (PS) I and II core proteins, and activities of antioxidant enzymes were examined. Among the Si sources, K2SiO3 application enhanced the axillary shoot multiplication and the uptake of Si on comparison with CaSiO3. Both forms of Si resulted in the enhancement of stomatal density, and PS-related protein such as PsaA and PsbA illustrating the apparent involvement of Si on the photosynthetic process. Nevertheless, addition of Si improved the antioxidant capacity during the in vitro shoot multiplication. Overall, the outcomes of the present study suggested that Si can be utilized as a supplementary source during the in vitro propagation of carnation.</P>

Porphyrin Dye/TiO₂ imbedded PET to improve visible-light photocatalytic activity and organosilicon attachment to enrich hydrophobicity to attain an efficient self-cleaning material

Min, Kyeong Su,Manivannan, Ramalingam,Son, Young-A. Elsevier 2019 Dyes and pigments Vol.162 No.-

<P><B>Abstract</B></P> <P>A visible-light sensitized, superhydrophobic, self-cleaning Polyethylene terephthalate (PET) fabric exhibiting photocatalytic dye degrading properties has been prepared by depositing anatase TiO<SUB>2</SUB>, porphyrin (TPPS, CuTPPS), and trimethoxy(octadecyl)silane (Si) onto the PET samples. The modified PET fabric showed superhydrophobicity, exhibiting a water contact angle (WCA) of 147°, and the ability to photodegrade rhodamine dye (RB), and the dye degradation ability of the modified fabric under visible light was monitored at different time intervals by UV–Vis spectroscopy. The degradation efficiency was found to be in the order PET/TiO<SUB>2</SUB>/TPPS > PET/TiO<SUB>2</SUB>/TPPS/Si > PET/TiO<SUB>2</SUB>/CuTPPS > PET/TiO<SUB>2</SUB>/CuTPPS/Si > PET/TiO<SUB>2</SUB> > PET. The photodegradation ability and superhydrophobicity of the modified PET samples in relation to coffee and ketchup stains were examined qualitatively. Due to its superhydrophobicity, water soluble impurities/coffee drops roll off the surface of the modified PET fabrics, resulting in stain-free fabric. The fabrics were characterized by UV–Vis, FESEM, XRD and XPS. The structures of the synthesized porphyrin and TiO<SUB>2</SUB> were confirmed by <SUP>1</SUP>H NMR spectroscopy and XRD analysis, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PET samples were modified to exhibit dual self-cleaning property. </LI> <LI> The photodegradation of dye stains in PET samples were achieved by inclusion of TiO<SUB>2</SUB> and porphyrin. </LI> <LI> Superhydrophobic behavior obtained by modifying the PET with trimethoxyoctadecylsilane </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>