02812nas a2200253 4500008004100000022001400041245009500055210006900150260013500219300000900354490000700363520185400370653001702224653001502241653002602256653001802282653001802300100002402318700002502342700002002367700001902387700003402406856011802440 2011 eng d a1347-946600aModeling & simulation of micro reactor with nitration of 2-methyl-4,6 dihydroxy-pyrimidine0 aModeling simulation of micro reactor with nitration of 2methyl46 aC/O JAPAN EXPLOSIVES INDUSTRY ASSOC, ICHIJOJI BLDG., 2-3-22 AZABUDAI, MINATO-KU, TOKYO, 106-0041, JAPANbJAPAN EXPLOSIVES SOCcJAN a9-200 v723 a

Nitration of 2-methyl-4,6-dihydroxypyrimidine (MDP) using concentrated sulfuric acid and nitric acid as nitrating mixture is a highly exothermic and hazardous reaction. Conducting such reaction in a batch reactor follow an unsteady state and its trajectory depends on various important parameters such as initial reactor temperature, initial composition of reaction mass, temperature of circulating coolant, etc. However, over all productivity, process control and safety of the batch process is highly restricted due to lower surface to volume ratio. In the present work, an effort has been made to over come the limitations of batch reactor by using the novel micro reactor device. Micro reactor is having extremely high surface to volume ratio, which has been explored to carry out nitration of MDP both numerically as well as experimentally and the results were compared with conventional batch reactor. The micro reaction system has been modeled using two dimensional (2-D) heat flow and mass transfer equations. The kinetic rate equation for nitration of MDP has evaluated experimentally by differential method which is used in modeling of the micro reactor. The numerical results from the 2-D model for conversion and temperature profile along the length and radius of micro reactor have been compared with corresponding results obtained from batch reactor. In order to validate the model, several experiments were conducted in micro reactor set-up with the variation of flow rate, residence time, concentration, temperature, etc. The experimental results from micro reactor revealed that nitration of MDP takes place even at much lower concentration and lower residence time with better control of temperature profile. Also, the reaction takes place in laminar region compared to turbulent region in corresponding batch reactor setup.

10a2-D modeling10a2-methyl-410a6 dihydroxypyrimidine10aBatch reactor10amicro reactor1 aMandal, Alok, Kumar1 aPandey, Raj, Kishore1 aAsthana, Nandan1 aKulkarni, Amol1 aKulkarni, Bhaskar, Dattatraya uhttps://library.ncl.res.in/content/modeling-simulation-micro-reactor-nitration-2-methyl-46-dihydroxy-pyrimidine-002834nas a2200253 4500008004100000022001400041245007900055210006900134260007100203300001400274490000700288520198600295653001402281653002002295653001302315653000802328653002602336653001802362100001902380700001902399700002702418700002202445856011302467 2013 eng d a0897-475600aLarge centimeter-sized macroporous ferritin gels as versatile nanoreactors0 aLarge centimetersized macroporous ferritin gels as versatile nan a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC a4813-48190 v253 a

Organized assemblies of bionanoparticles such as ferritin provides templates that can be exploited for nanotechnological applications. Organization of ferritin into well-defined three-dimensional assemblies is challenging and has attracted considerable attention recently. We have synthesized, for the first time, large (centimeter-sized) self-standing macroporous scaffold monoliths from ferritin bionanoparticles, using dynamic templating of surfactant H-1 domains. These scaffolds comprise three-dimensionally connected strands of ferritin, organized as a porous gel with porosity similar to 55 mu m. The iron oxide inside the ferritin scaffold can be easily replaced with catalytically active monodisperse zerovalent transition metal nanoparticles using a very simple protocol. Since the ferritin is cross-linked in the scaffold, it is significantly robust with enhanced thermal stability and better tolerance toward several organic solvents in Comparison to the native ferritin bionanoparticle. In addition, the scaffold macropores facilitate substrate and reagent transport and hence the monoliths containing active Pd or iron oxide nanoparticles inside apo-ferritin bionanoparticles were used as a recyclable heterogeneous catalyst for the oxidation of 2,3,6-trimethyl phenol to 2,3,6-trimethyl-1,4-benzoquinone (precursor for Vitamin E synthesis) and for Suzuki-Miyaura cross-coupling reaction in both aqueous and organic solvents. The protein shell around the nanoparticles protects them from agglomeration, a phenomenon that otherwise plagues nanoparticles-based catalysis. The presence of macropores allow the ferritin scaffold to act as catalytic monolith for continuous flow reactions having rapid reaction rates, while offering a low pressure drop. Finally, the Pd@apo-ferritin scaffold was immobilized inside a steel cartridge and used for the continuous flow hydrogenation of alkenes to their corresponding alkanes for 15 cycles without any loss of activity.

10acatalysis10acontinuous flow10aferritin10agel10amacroporous materials10aSelf-assembly1 aKumari, Sushma1 aKulkarni, Amol1 aKumaraswamy, Guruswamy1 aGupta, Sayam, Sen uhttps://library.ncl.res.in/content/large-centimeter-sized-macroporous-ferritin-gels-versatile-nanoreactors-003071nas a2200169 4500008004100000245013300041210006900174260000800243300001400251490000600265520242800271100001902699700001902718700002302737700001802760856012302778 2017 eng d00aMicroreactor-based continuous process for controlled synthesis of poly-methyl-methacrylate-methacrylic acid (PMMA) nanoparticles0 aMicroreactorbased continuous process for controlled synthesis of cAPR a3404-34170 v53 aWe have developed a microreactor-based continuous process for synthesizing PMMA nanoparticles (NPs), based on the principle of nanoprecipitation. Our objective was to identify the critical parameters governing the size of nanoparticles, produced in microreactors, to enable reproducible synthesis of mono-disperse particles. Experiments were carried out in a microreactor, where parameters like flow rates of aqueous and organic phases, residence time and polymer concentrations were varied to examine their influence on particle size and homogeneity. The results from Dynamic Light Scattering confirmed that the particle size decreased with decreasing residence time, whereas when the aqueous to organic phase flow rate ratio was changed sequentially from 9 : 1, 4 : 1, 7 : 3, 3 : 2, to 1 : 1 (v/v), the particle size increased. Particles fabricated using a microreactor demonstrated a narrow and homogenous distribution, thus confirming their monodispersity. TEM, SEM and XRD were also performed for morphology analysis and phase identification of the particles. Further, paclitaxel encapsulated PMMA nanoparticles were prepared using the microreactor, demonstrating an increase in mean size of around 30 nm and a slightly higher polydispersity index compared to the blank nanoparticles. The drug encapsulation efficiency and drug release kinetics of these nanoparticles were comparable to those prepared in batch-experiments, thus establishing the suitability of the technology for preparing drug-loaded nanoparticles. Also, it was observed that at all the residence times (10 min to 10 s), about 80% of the polymer got transformed into nanoparticulate form, thus confirming the efficiency of the microreactor. In recent times, much work has been conducted to synthesize polymeric nanoparticles using different types of microreactors, but they lack detailed investigation of the effect of various parameters on the physiochemical properties of the resulting particles. Our investigation synthesizes PMMA NPs, using microreactor technology, for the very first time, to the best of our knowledge. Furthermore, we have performed a detailed analysis of the influence of various process parameters on the size and uniformity of the resulting nanoparticles. These critical parameters can serve as a useful tool to synthesize a myriad of nanoparticles of alternative polymers, using microreactor technology.1 aDobhal, Anurag1 aKulkarni, Amol1 aDandekar, Prajakta1 aJain, Ratnesh uhttps://library.ncl.res.in/content/microreactor-based-continuous-process-controlled-synthesis-poly-methyl-methacrylate02126nas a2200241 4500008004100000022001400041245011400055210006900169260000800238300001000246490000600256520133800262653001901600653002501619653001101644653000901655653002001664100002201684700001501706700001801721700001901739856012601758 2018 eng d a2062-249X00aContinuous flow synthesis of micron size silica nanoparticles: parametric study and effect of dosing strategy0 aContinuous flow synthesis of micron size silica nanoparticles pa cJUN a59-670 v83 a

This work for the first time reports continuous flow synthesis of silica nano-particles of size over 1 mu m using a simple tubular reactor. The systematic approach involves the study of effect of various parameters like: ammonia concentration, water concentration, electrolyte concentraton, temperature, solvent, residence time and mode of TEOS injection over a wide range. A combination of ethanol and butanol was used as the medium with relatively lower polarity. Various process parameters were optimized to obtain highly monodispersed particles of size up to 600 nm and high yield (up to 90%). Attempts of reducing the reaction time by increasing temperature or concentrations of any of the reagents resulted in significant polydispersity and even in the formation of random shape agglomerates. At the optimized conditions almost complete conversion of TEOS happenned within 40 min and further growth of particles was achieved by adding TEOS using multipoint injection approach. While multipoint dosing resulted in the formation of very small number of secondary particles, the larger particles continued to grow beyond 800 nm. Further reduction in the polarity of reaction medium was achieved by adding 20% v/v of toluene, which without changing homogeneity of the solution resulted in particles as large as 0.9-1.1 mu m.

10aFlow synthesis10aMultipoint injection10asilica10aTEOS10aTubular reactor1 aJundale, Rajashri1 aBari, Atul1 aThara, Chinnu1 aKulkarni, Amol uhttps://library.ncl.res.in/content/continuous-flow-synthesis-micron-size-silica-nanoparticles-parametric-study-and-effect01391nas a2200169 4500008004100000245009900041210006900140260000800209300001300217490000800230520076700238100001901005700002701024700002701051700001901078856012401097 2018 eng d00aModulation of reactivity of singlet radical pair in continuous flow: photo-fries rearrangement0 aModulation of reactivity of singlet radical pair in continuous f cJUN a 316-3210 v3643 a

Photo-Fries rearrangement of phenyl benzoate is studied using continuous flow for modulating the reactivity of singlet radical pair by changing the viscosity of the solvent. The effect of flow and proximity of the reactants with the light source on the reactivity of radical pair, formed from singlet excited state was investigated in details. In non-viscous solvent, the results from flow synthesis were comparable to batch reactor. In viscous solvents, selectivity of ortho- and para-isomers (o-/p- isomer) of the product could be controlled by changing viscosity as well as the flow rate. Using flow synthesis, ortho- and para-isomer ratio was obtained as high as 8.45 which are twice as compared to batch experiment with in fraction of residence time.

1 aKarjule, Neeta1 aSharma, Mrityunjay, K.1 aNithyanandhan, Jayaraj1 aKulkarni, Amol uhttps://library.ncl.res.in/content/modulation-reactivity-singlet-radical-pair-continuous-flow-photo-fries-rearrangement00589nas a2200157 4500008004100000022001400041245010000055210006900155260000800224300001200232490000700244100002200251700001800273700001900291856012100310 2021 eng d a2062-249X00aEditorial special issue in the journal of flow chemistry: engineering aspects of flow chemistry0 aEditorial special issue in the journal of flow chemistry enginee cSEP a211-2120 v111 aKockmann, Norbert1 aHartman, Ryan1 aKulkarni, Amol uhttps://library.ncl.res.in/content/editorial-special-issue-journal-flow-chemistry-engineering-aspects-flow-chemistry03504nas a2200253 4500008004100000022001400041245018200055210006900237260000800306300001600314490000700330520257000337100002302907700002502930700002902955700001602984700001803000700002503018700001703043700002303060700001903083700001703102856013103119 2022 eng d a2050-752600aDirect (hetero)arylation (DHAP) polymerization of conjugated polymers - new A-B-A monomer design for P(NDI2OD-T2) & the challenges of adopting DHAP for continuous flow processes0 aDirect heteroarylation DHAP polymerization of conjugated polymer cSEP a13025-130390 v103 a

P(NDI2OD-T2), also known as Polyera ActivInk N2200, was synthesized by the atom-economic direct hetero arylation polymerization (DHAP) route using a newly designed A-B-A monomer. The new monomer design involved flanking naphthalene diimide with bithiophene units in the bay position, which was further polymerized with bay substituted 1,4-dibromo naphthalene diimide, to afford the same polymer structure as P(NDI2OD-T2). The new monomer design resulted in a very high molecular weight (M-n: 99.5 kDa, D-M: 2.8) defect-free polymer in a quantitative yield by the DHAP batch process using 1,2,4-trichlorobenzene (TCB) as the solvent. DFT studies revealed that the abstraction of the alpha-proton from the naphthalene diimide substituted 2,2 `-bithiophene was favorable by 2.6 kcal mol(-1) (Delta Delta G) as compared to that from 2,2 `-bithiophene. The reason for this improved C-H activation at the alpha position can be attributed to the presence of C-HMIDLINE HORIZONTAL ELLIPSIS pi stabilizing interactions in naphthalene diimide substituted 2,2 `-bithiophene, which strengthens upon the extended charge delocalization throughout the ring, thus stabilizing the conjugate base generated after the proton abstraction. Continuous flow polymerization was carried out by pumping the DHAP reaction mixture including the monomers, catalyst, and additive (pivalic acid) solubilized in degassed TCB through a pre-heated glass condenser packed with K2CO3 and Celite under aerobic conditions. Reproducible molecular weights of M-n: 29.5 kDa, D-M: 1.7 were obtained at much lower concentrations of reactant mixture compared to that for batch polymerization. This is the first report of the synthesis of P(NDI2OD-T2) by a Continuous Flow Process adopting the DHAP route to obtain a defect-free polymer with reasonable molecular weights. P(NDI2OD-T2) was also synthesized by Stille polymerization as a reference control sample to compare the thermal and charge carrier transport properties of the DHAP polymers. Organic field-effect (OFET) mobility measurements indicated mobility values in the order of 10(-3) cm(2) V-1 s(-1) for the DHAP batch polymer (using the novel monomer design). The P(NDI2OD-T2) synthesized by DHAP batch using the commonly used starting materials - bisbromo naphthalene diimide and bithiophene, exhibited OFET mobilities which were one order less, similar to 10(-4) cm(2) V-1 s(-1). This observation highlights the importance of structural design in the monomer to enhance reactivity and thereby the bulk properties using the DHAP route.

1 aKakde, Navnath, R.1 aBharathkumar, H., J.1 aWavhal, Bhaiyyasaheb, A.1 aNikam, Arun1 aPatil, Suneha1 aDash, Soumya, Ranjan1 aVanka, Kumar1 aKrishnamoorthy, K.1 aKulkarni, Amol1 aAsha, S., K. uhttps://library.ncl.res.in/content/direct-heteroarylation-dhap-polymerization-conjugated-polymers-new-b-monomer-design-pndi2od