id
int64
0
3.42M
contents
stringlengths
8
8.5k
200
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionIn this study, we innovatively fabricated an Au@Cu 2 O-ZnO ternary heterojunction, the first of its kind.Following this, we applied an in situ polymerization technique to seamlessly incorporate the Au@Cu 2 O/ZnO het...
201
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionIn the synthesis of the Au@Cu 2 O@ZnO ternary heterojunction, we started by dissolving 0.1 g of CuCl 2 in 180 mL of ultra-pure water.Then, 2.02 g of sodium dodecyl sulfate (SDS) was added and completely dissolved, f...
202
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionTo initiate the aqueous solution polymerization process, the autoclave's internal environment was carefully heated to a temperature of 220 • C. Concurrently, the pressure relief valve of the autoclave was finely adj...
203
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionFourier transform infrared analysis (FTIR) was performed using Nicolet 6700 FTIR (Thermo Fisher Scientific, Waltham, MA, USA) with a range of 600-4000 cm −1 and a resolution of 4 cm −1 .X-ray diffraction (XRD) of th...
204
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionusing an Instron 365 material testing machine (Instron, Boston, MA, USA), according to ISO 527-1:2012 [29].
205
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionCharacterization
206
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionFourier transform infrared analysis (FTIR) was performed using Nicolet 6700 FTIR (Thermo Fisher Scientific, Waltham, MA, USA) with a range of 600-4000 cm −1 and a resolution of 4 cm −1 .X-ray diffraction (XRD) of th...
207
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionusing an Instron 365 material testing machine (Instron, Boston, MA, USA), according to ISO 527-
208
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionAntibacterial Activity of PA66/Au@Cu 2 O-ZnO Samples Methodology for the antibacterial test: Antibacterial activity was assessed against an array of two bacterial strains: S. aureus (ATCC 6538) as Gram-positive bac...
209
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionwith even shell coverage was prepared successfully through adding an Au@Cu2O heterostructure into a 0.01 M zinc salt reaction system, under certain pH and temperature.The TEM and SEM morphology of Au@Cu2O and Au@Cu2...
210
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionThe interfacial compatibility of antibacterial agents in the polymer matrix significantly influences the properties of composite materials.Therefore, scanning electron microscopy (SEM) was used to monitor the cross-...
211
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionthese particles (Figure 4b-e) clearly reveals the presence of Au, Cu, and Zn indicating some aggregation of the nanoheterostructures.All of these findings confirm that Au@Cu2O-ZnO was successfully loaded onto the PA...
212
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionstretching vibration band of PA66 decreased relative to the -CH 2 band.This is due to the coordination of metal ions with the C=O peak, which reduced the stretching vibration of C=O.This alteration affected the inte...
213
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionXPS tests were also performed to confirm the formation of coordination bonds in PA66 composites.The C 1s and O 1s XPS spectra of the pure PA66 and PA66/Au@Cu ZnO composites are shown in Figure 6.It can be observed t...
214
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionXPS tests were also performed to confirm the formation of coordination bonds in the PA66 composites.The C 1s and O 1s XPS spectra of the pure PA66 and PA66/Au@Cu2O-ZnO composites are shown in Figure 6.It can be obse...
215
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionpolymerization process rather than simply being doped into PA66.
216
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionCrystallization and Melting Behaviors of PA66/Au@Cu 2 O-ZnO Composites The DSC curves of pure PA66 and PA66/Au@Cu 2 O-ZnO composites are presented in Figure 7, and the results are summarized in Table 1.With the inc...
217
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionThe DSC curves of pure PA66 and PA66/Au@Cu2O-ZnO composites are presented in Figure 7, and the results are summarized in Table 1.With the increasing content of heterojunction antibacterial agents, the melting peak o...
218
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionpeak's relative intensity grew, eventually surpassing the α2 peak's height.This likely resulted from heterojunction complexation with PA66, altering hydrogen bonds between molecular chains and promoting α1 surface g...
219
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionPolymers 2024, 16, x FOR PEER REVIEW 9 of 14 23.7°, and 20.5° and 23.8°, respectively [38].With increased heterojunction loading, these peaks shifted to lower angles.The α1 peak's relative intensity grew, eventually...
220
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionThe thermal stability of PA66 and PA66/Au@Cu2O-ZnO composites were evaluated using TG and DTG. Figure 9 shows TG and DTG thermograms of PA66 and PA66/Au@Cu2O-ZnO composites, and the relevant thermal parameters for P...
221
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunctionas a weak alkaline, can catalyze the degradation of PA66 and decrease the thermal stability of PA66/Au@Cu 2 O-ZnO composites [42,43].
222
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionMechanical Properties of PA66/Au@Cu 2 O-ZnO Composites The mechanical properties of PA66 and the PA66/Au@Cu 2 O-ZnO composites, as shown in Figure 10, reveal that the integration of the Au@Cu 2 O-ZnO heterojunction...
223
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionTo evaluate antimicrobial performance, clinically isolated Escherichia coli (ATCC 25922, Gram-negative) and Staphylococcus aureus (ATCC 6538, Gram-positive) were tested, as they are associated with medical infection...
224
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionIn Table 3, the antibacterial efficacies of both standard PA66 and PA66/Au@Cu2O-ZnO composites against Escherichia coli and Staphylococcus aureus are compared under varying conditions of darkness and light over a 24...
225
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionFigure 3 . 3 Figure 3. SEM images of fracture sections: (a) pure PA66; (b) 400 ppm; (c) 800 ppm; (d) 1200 ppm. Figure 3 . 3 Figure 3. SEM images of fracture sections: (a) pure PA66; (b) 400 ppm; (c) 800 ppm; (d) 1...
226
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionFigure 6 . 6 Figure 6.C 1s and O 1s XPS spectra of PA66 and PA66/Au@Cu2O-ZnO composites.Figure 6. C 1s and O 1s XPS spectra of PA66 and PA66/Au@Cu 2 O-ZnO composites. Figure 7 . 7 Figure 7. DSC heating curves (a) ...
227
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionTable 1 . 1 The DSC results of PA66 and PA66/Au@Cu2O-ZnO composites. SampleTm, °CΔHm, J g −1Tc, °CXc, %PA66261.6249.65219.6026.13400 ppm261.0360.42222.6531.80800 ppm260.1054.19221.4728.521200 ppm258.7043.78216.4123....
228
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionTable 3 . 3 The antibacterial tests against Escherichia coli and Staphylococcus aureus with different samples. BacteriumSampleAntibacterial Rate (%) Under LightNo LightPA66No effectNo effectE. coliPA66/Au@Cu 2 O-ZnO...
229
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionData Availability Statement:The data presented in this study are available upon request from the corresponding author.Funding: This research received no external funding.Institutional Review Board Statement: Not app...
230
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionSynthesis Phosphorus-Sulfur Reactive Flame Retardant for Polyamide 66 with High Flame Retardant Efficiency and Low Smoke. Y Wu, T Yang, Y Cheng, T Huang, B Yu, Q Wu, M Zhu, H Yu, 10.1016/j.polymdegradstab.2023.11037...
231
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionPreparation and Properties of Halogen-Free Flame-Retardant Layered Silicate-Polyamide 66 Nanocomposites. K Tamura, S Ohyama, K Umeyama, T Kitazawa, A Yamagishi, 10.1016/j.clay.2016.02.027Appl. Clay Sci. 1262016 Sit...
232
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionOrganocatalytic Copolymerization of Cyclic Lysine Derivative and ε-Caprolactam toward Antibacterial Nylon-6 Polymers. J Lian, J Chen, S Luan, W Liu, B Zong, Y Tao, X Wang, 10.1021/acsmacrolett.1c00658ACS Macro Lett....
233
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunction. H Li, J Zhong, H Zhu, Y Yang, M Ding, L Luo, Y Huo, H Li, 10.1021/acsabm.9b00644Nanocomposites with Enhanced Photocatalytic Antibacterial Activity toward Acinetobacter Baumannii. ACS Appl. Bio Mater. 22019 Effect...
234
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionAu@Cu 2 O Core-Shell Structure for High Sensitive Non-Enzymatic Glucose Sensor. Y Su, H Guo, Z Wang, Y Long, W Li, Y Tu, 10.1016/j.snb.2017.09.056Sens. Actuators B Chem. 2552018 Cu 2 O/ZnO Ternary Nanocomposite for...
235
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionPlastics-Polyamides-Determination of Viscosity Number. International Organization for Standardization. ISO. 3072019. 2019 Plastics-Determination of tensile properties-Part 1: General Principles. International Organ...
236
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionInnovative UVC Light (185 Nm) and Radio-Frequency-Plasma Pretreatment of Nylon Surfaces at Atmospheric Pressure and Their Implications in Photocatalytic Processes. M I Mejía, J M Marín, G Restrepo, C Pulgarín, E Mie...
237
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary HeterojunctionThermal Properties and Combustion Characterization of Nylon 6/MgAl-LDH Nanocomposites via Organic Modification and Melt Intercalation. L Du, B Qu, M Zhang, 10.1016/j.polymdegradstab.2006.08.001Polym. Degrad. Stab. 9...
238
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidEffects of acid dissociation and ionic solutions on the aggregation of 2-pyrone-4,6-dicarboxylic acid Jianping Li jianping.li@anl.gov Department of Chemical and Biological Engineering University of Wisconsin-Madison ...
239
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidLignocellulosic biomass is an abundant renewable feedstock which can potentially be used for the sustainable production of fuels and high-value chemicals, thereby reducing dependence upon petroleum and contributing to d...
240
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic Acidaggregation process is resolving molecular-scale details of aggregate structure.Although experiments have revealed the precipitation of PDC in solutions containing alkali metal ions, 24 limited work has studied the aggr...
241
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic Acidleveraged MD simulations to investigate the role of ionic interactions in aqueous lithium bistriflimide solutions as a function of concentration and found that highly interconnected ion-rich network forms in the super-c...
242
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidMolecular Dynamics Simulations Classical molecular dynamics (MD) simulations were performed to analyze PDC aggregation in water or in various ionic solutions.All MD simulations were performed in the isothermalisobaric ...
243
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFor comparison, we also considered a system consisting of 100 neutral PDC molecules and 6246 water molecules without additional ions.All systems were initiated in a cubic simulation box with dimensions of 6 nm in all di...
244
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic Acidis an additional term that represents ion-induced dipole interactions when M(II) ions are present in the system, with κ = 0 if only monovalent M(I) ions are present in the system.If M(II) ions are present in the system,...
245
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidIdentification of PDC Aggregates and Parallel Clusters We developed and implemented a clustering method to identify PDC molecular aggregates and the degree to which PDC molecules stack in parallel configurations within...
246
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidPairs of PDC molecules within the same aggregate that further satisfy Equation 5were considered to be in a parallel stacking configuration and were defined as being within the Aggregate Order Parameters We defined tw...
247
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidVisual Molecular Dynamics (VMD) was used for visualisation. 51We selected the reference PDC molecule as the molecule that was found in a parallel cluster with the highest frequency across all simulation configurations.R...
248
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidThe regions of highest PDC density (indicated by the blue surface in Figure 3b 3c and 3d).As shown in Figure 3c, the probability distribution for M c is peaked near 17 with a small value near 0 and a long tail for large...
249
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidSolution The formation of randomly packed structures by neutral PDC molecules suggests a role for ion-mediated interactions in promoting parallel stacking.To investigate the effect of such interactions, we next investi...
250
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFor PDC 2− in the presence of Li + ions, the probability distribution for M c is peaked near 24 (Figure 4b), representing a reduced peak compared to PDC − , and the distribution of R c also indicates a high probability ...
251
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFor PDC − , all solutions promote the formation of PDC aggregates and the probability distribution of M c is peaked near 30 (Figure 5a, left).Moreover, all solutions strongly favor the parallel stacking of aggregated PD...
252
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidAs discussed in the previous section, we observe diverse PDC aggregation patterns within the solutions of monovalent metal ions, with an increase in aggregation and parallel stacking observed for the higher charge densi...
253
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidThis disrupts the aggregation of water molecules and hence allows more space for PDC aggregation around the reference PDC ion.This also indicates that for the ionic solution of Mg 2+ , at the second degree of acid disso...
254
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFigure 2 : 2 Figure 2: Geometries and stacking structures between two PDC molecules.a) Geometries and computation of dihedral angle between two PDC molecules.The molecular plane is determined using carbon atoms C08, C09...
255
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic Acid) encircle the PDC molecule, indicating that surrounding PDC molecules can interact with the reference PDC molecule at positions on or below the surface of the pyran ring.This suggests that stacking interactions are not...
256
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFigure 4 : 4 Figure 4: Effect of acid dissociation on PDC aggregation in Li + solution.a) At the first degree of acid dissociation, b) at the second degree of acid dissociation.Left: concentration indicator of aggregate...
257
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFor PDC 2 − 2 , the Li + solution leads to different PDC stacking behavior compared with other M(I) ionic solutions by not facilitating PDC aggregation (Figure 5a Right) or promoting a high degree of parallel stacking (...
258
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFor PDC − , solutions of Be 2+ , Ca 2+ , Sr 2+ , and Ba 2+ facilitate the formation of aggregated PDC ions with the probability distribution of M c peaked near 25 -30 (Figure 6a Left), which is similar to observations ...
259
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidFirst, we perform atomistic molecular dynamics simulations of PDC at different degrees of acid dissociation and in various metal ion solutions.We then implement molecular clustering analysis based on the minimum distan...
260
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidTo compute R c , we first in parallel stacking configurations was counted by further applying Equation 5 to pairs of PDC molecules, thereby generating a set of parallel clusters.We note that multiple distinct parallel c...
261
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidElectrification of gasification-based biomass-to-X processes-a critical review and in-depth assessment. M Dossow, D Klüh, K Umeki, M Gaderer, H Spliethoff, S Fendt, 10.26434/chemrxiv-2024-gnv68https://orcid.org/0000-000...
262
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidCrystal nucleation rates from probability distributions of induction times. S Jiang, J H Ter Horst, Crystal growth & design. 112011 Physical principles of membrane organization. J Israelachvili, S Marčelja, R G Horn, Q...
263
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidAssembly of amphiphilic hyperbranched polymeric ionic liquids in aqueous media at different pH and ionic strength. V F Korolovych, P A Ledin, A Stryutsky, V V Shevchenko, O Sobko, W Xu, L A Bulavin, V V Tsukruk, 10.2643...
264
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidAttraction between Like-Charged Macroions Mediated by Specific Counterion Configurations. A Stelmakh, W Cai, A Baumketner, The Journal of Physical Chemistry B. 1232019 Ionbridges and lipids drive aggregation of same-ch...
265
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidMolecular systems engineering. C Adjiman, A Galindo, E N Pistikopoulos, M C Georgiadis, V Dua, Ligand-mediated short-range attraction drives aggregation of charged monolayer-protected gold nanoparticles. R C Van Lehn,...
266
Effects of Acid Dissociation and Ionic Solutions on the Aggregation of 2-Pyrone-4,6-dicarboxylic AcidMolecular properties of 2-pyrone-4, 6-dicarboxylic acid (PDC) as a stable metabolic intermediate of lignin isolated by fractional precipitation with Na+ ion. T Michinobu, M Bito, Y Yamada, Y Katayama, K Noguchi, E Masai...
267
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersDesigning self-propelled, chemically active sheets: Wrappers, flappers, and creepers Abhrajit Laskar C H E M I S T R Y Oleg E Shklyaev C H E M I S T R Y Anna C Balazs C H E M I S T R Y Designing self-propelled, chemically act...
268
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersINTRODUCTION Chemically active, catalytic objects in aqueous environments can autonomously perform a variety of vital functions (1,2). The capabilities and functionalities of these active objects are determined by the specific way they...
269
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersHerein, we develop a model for microscopic, catalyst-coated elastic sheets and show that the chemically generated flows around the sheet "sculpt" this layer into various forms that can provide different functionalities. This functionali...
270
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersRESULTS Theoretical modeling For the chemically active objects to perform mechanical work in the host solution, the chemical reactions occurring at the object must be coupled to the motion of the surrounding fluid. One particularly e...
271
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersIn our model, the solutal buoyancy force is given by F b = gr 0 ∑b i C i , which depends on gravity g, solvent density r 0 , the concentrations of each dissolved chemical C i , and the corresponding expansion coefficients b i (11,12). T...
272
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersUnless stated otherwise, we impose no-slip boundary conditions (u = 0) at the solid walls of the container. For the reagent C i , we use three different boundary conditions to describe different surface properties of the container walls...
273
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersHere, the maximal reaction rate r e m;sheet ¼ k e ½E incorporates the reaction rate per molecule of enzyme k e and the areal enzyme concentration [E], and K M is the Michaelis constant. As described below, we also tailor the maximal rea...
274
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThe density of the sheet (r s ) is greater than the density of the pure solution (r 0 ), and thus, the sheet undergoes sedimentation. Consequently, all the nodes in the sheet experience an additional external force, F g = V(r s − r 0 )g...
275
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersIf we consider the linear response regime (slow flows), then the fluid velocities are proportional to the ratio between the buoyancy force r 0 gbDCL 3 , moving the solution within a volume L 3 , and the viscous force n 2 r 0 , resisting...
276
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersDesigning active sheets For the enzymatic chemical reactions considered here, solutal buoyancy is the dominant mechanism that gives rise to the fluid flow (11,12). While a number of different chemical reactions can produce such solutal ...
277
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersInitially, the elastically relaxed petals stay parallel to the bottom wall and H 2 O 2 is then uniformly dispersed in the chamber. The catalase decomposes H 2 O 2 to less dense products (H 2 O and O 2 ), which generate an inward flow, w...
278
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersUltimately, all the reactants for the system in Fig. 1C are consumed and the flow ceases to circulate. To release the elastic stresses within the deformed sheet, the petals now open up and expose the decorative sphere (Fig. 1D). The sep...
279
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThe dynamic behavior and coordination among the individual petals can be tailored further by coating the petals with different catalysts and introducing a cascade of chemical reactions, where the product of one catalytic reaction is the...
280
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersIn harnessing a cascade of chemical reactions to perform mechanical work, the rates of the different reactions should be coordinated to achieve the desired time-dependent behavior. The rates of the reactions To obtain an appreciable tim...
281
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersare characterized by the product r e m;petal S (in moles per second), where r e m;petal is the maximal reaction rate and S is the surface area of a catalytic site (e.g., the size of a node in our simulations). Notably, the maximal rate ...
282
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThis spatial arrangement of the two different enzymes on the container walls ensures that one set of petals (e.g., pink) remains localized on the bottom wall as the opposing petals (green) rise up and join together. The schematic in Fig...
283
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersIn addition to Eq. 8, we now use the following chemistry PNPP → acid phosphatase PNP þ NaH 2 PO 4ð10Þ where the enzyme acid phosphatase (AP) decomposes p-nitrophenylphosphate hexahydrate (PNPP) into p-nitrophenol (PNP) and monosodium ph...
284
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersNotably, a passive sheet (i.e., not coated with catalysts) in the reactant-filled chamber cannot achieve the dynamic behavior described above. The catalytic coating is necessary to generate the flows that bend the compliant layer and th...
285
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersIn the first example, we introduced small "bumps" that are modeled as sets of passive particles (gray spheres in Fig. 5) anchored at regular intervals on the bottom surface; the no-slip boundary conditions are imposed at these stationar...
286
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThe second example of a morphing and moving sheet is inspired by the inchworm, which repeatedly bends and extends its body to achieve locomotion. To mimic this behavior, we use a catalase-coated sheet that is heavier at the front and ba...
287
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersIn the case of a completely passive sheet, the layer moves along the surface in a flat configuration, driven by the convective flows generated by the release of the heavy reactant into the aqueous solution (see Fig. 6A). On the other ha...
288
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersDISCUSSION We have undertaken the first study of the response of a flexible, catalyst-coated sheet to self-generated flow fields, which arise from the catalytic reaction in the host solution. The findings from our computational models ...
289
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThrough these studies, we isolated behavior that occurs when a chemical reaction cascade (where the product of one reaction is the reactant for the next) is coupled to deformable, chemically patterned sheets (as in Fig. 2). We demonstra...
290
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersMoving forward, these studies provide a foundation to address another intriguing scientific challenge: how to harness the catalytic reactions to alter not only the shape and motion of the sheets but also the sheet's material properties....
291
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThe forces exerted by the sheet on the fluid are included in F el and were calculated using the IB approach (14,25). The implementation of the fluid-structure interaction via the IB method (14,25) provides zero fluid velocities at the d...
292
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersThe size of the fluid-filled chamber is L x × L y × L z = 30 by 30 by 15 in lattice Boltzmann units (Dx). To maximize the effects responsible for interactions of the flow in the channel with the structure of the chemically active sheet,...
293
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersFig. 1 . 1Chemomechanical response of catalse-coated sheet. (A) Top-down view of a fluidic chamber containing a catalase-coated flower-like, elastic sheet composed of nodes (indicated by green dots) and connected by bonds (black lines) ...
294
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersFig. 2 . 2Top and side views of the bending and unbending of the respective catalase-coated (green) and GOx-coated (pink) petals. Coordinated behavior of the petals involves the reaction cascade in Eqs.8 and 9. (A) Inward flow generated...
295
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersFig. 4 . 4Chemical logic gates, or flappers. Coating the petals with catalase (green) and AP (yellow) allows the system to perform different logic operations, such as XOR and AND [see corresponding truth tables (A) and (B)], as well as ...
296
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersFig. 6 . 6Creeping motion of active sheets. Response of passive (A) and active (B to G) sheets to the sequential influxes of H 2 O 2 (at a rate R = 1.8 × 10 −9 mol s −1 ). Initially, H 2 O 2 is introduced at the right end; in subsequent...
297
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersEnzyme catalysis to power micro/ nanomachines. X Ma, A C Hortelão, T Patiño, S Sánchez, ACS Nano. 10X. Ma, A. C. Hortelão, T. Patiño, S. Sánchez, Enzyme catalysis to power micro/ nanomachines. ACS Nano 10, 9111-9122 (2016). Self-powere...
298
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersTransport of cargo by catalytic Janus micro-motors. L Baraban, M Tasinkevych, M N Popescu, S Sanchez, S Dietrich, O G Schmidt, Soft Matter. 8L. Baraban, M. Tasinkevych, M. N. Popescu, S. Sanchez, S. Dietrich, O. G. Schmidt, Transport of...
299
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepersNanoparticle stripes, grids, and ribbons produced by flow coating. H S Kim, C H Lee, P K Sudeep, T Emrick, A J Crosby, Adv. Mater. 22H. S. Kim, C. H. Lee, P. K. Sudeep, T. Emrick, A. J. Crosby, Nanoparticle stripes, grids, and ribbons p...