Limits...
Optimum periodicity of repeated contractile actions applied in mass transport.

Ahn S, Lee SJ - Sci Rep (2015)

Bottom Line: The characteristic repeatability and periodicity are expected to be optimized in effective system-specific functions.Optimized contractile periodicity exists for effective energy impartment to flow in a one-valve system.In the sequential contractile actions for a multi-valve system, synchronization with the fluid flow is critical for effective mass transport.

View Article: PubMed Central - PubMed

Affiliation: 1] Biofluid and Biomimic Research Center, Pohang University of Science and Technology, Pohang, 790-784, Korea [2] Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.

ABSTRACT
Dynamically repeated periodic patterns are abundant in natural and artificial systems, such as tides, heart beats, stock prices, and the like. The characteristic repeatability and periodicity are expected to be optimized in effective system-specific functions. In this study, such optimum periodicity is experimentally evaluated in terms of effective mass transport using one-valve and multi-valve systems working in contractile fluid flows. A set of nanoscale gating functions is utilized, operating in nanocomposite networks through which permeates selectively pass under characteristic contractile actions. Optimized contractile periodicity exists for effective energy impartment to flow in a one-valve system. In the sequential contractile actions for a multi-valve system, synchronization with the fluid flow is critical for effective mass transport. This study provides fundamental understanding on the various repeated periodic patterns and dynamic repeatability occurring in nature and mechanical systems, which are useful for broad applications.

No MeSH data available.


(a) [I] TEM image of gold nanoparticle (AuNP) use for linterlinking. Binary functional polyethylene oxide (PEO) having EO unit number of n = 227 (2PEG 10000) is used for linking AuNPs. Representative images of the designed nanocomposites. [II] TEM, [III] X-ray nanoscopy (XN) and [IV] X-ray microscopy (XM). (b) Small angle X-ray scattering (SAXS) results of the designed AuNP-PEG nanocomposite in solution state in broad q ranges (two Sample-to-detector distance conditions are combined). A critical q value (marked by q*) exist from which temperature-responsiveness is diversified, indicating dual regions of the designed network: stable large-scale domain at low q and responsive small-scale domain at high q. Characteristic size is determined according to the temperature detected by q1 (60°C), q2 (40°C) and q3 (20°C). (c) Illustration of responsive network structures. Pore size variation of the nanocomposites in PVA matrix induced by the stimuli-responsive PEOs through which permeates are transported. [I] Swollen PEOs generates (or block) small path for permeate molecules. [II] Shrunken PEOs allow relatively wide pathway for effective permeate transport. The correlation lengths (ζ) are determined based on the pictures below. Bold lines denote stable connection, whereas dotted lines indicates flexibly responsive chains by the external stimuli.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4306965&req=5

f1: (a) [I] TEM image of gold nanoparticle (AuNP) use for linterlinking. Binary functional polyethylene oxide (PEO) having EO unit number of n = 227 (2PEG 10000) is used for linking AuNPs. Representative images of the designed nanocomposites. [II] TEM, [III] X-ray nanoscopy (XN) and [IV] X-ray microscopy (XM). (b) Small angle X-ray scattering (SAXS) results of the designed AuNP-PEG nanocomposite in solution state in broad q ranges (two Sample-to-detector distance conditions are combined). A critical q value (marked by q*) exist from which temperature-responsiveness is diversified, indicating dual regions of the designed network: stable large-scale domain at low q and responsive small-scale domain at high q. Characteristic size is determined according to the temperature detected by q1 (60°C), q2 (40°C) and q3 (20°C). (c) Illustration of responsive network structures. Pore size variation of the nanocomposites in PVA matrix induced by the stimuli-responsive PEOs through which permeates are transported. [I] Swollen PEOs generates (or block) small path for permeate molecules. [II] Shrunken PEOs allow relatively wide pathway for effective permeate transport. The correlation lengths (ζ) are determined based on the pictures below. Bold lines denote stable connection, whereas dotted lines indicates flexibly responsive chains by the external stimuli.

Mentions: Citrate-stabilized colloidal gold nanoparticles (AuNPs) are prepared in aqueous solution. The concentration is adjusted to be around 2.4 × 1012 AuNPs/mL (Supporting Information)1213. The transmission electron microscopy (TEM) mage in Figure 1a[I] confirms the average diameter of the prepared single AuNP is 20 nm diameter. Binary thiol end-capped functional polyethylene oxide (PEO) are incorporated for AuNP interconnection. The molecular weight between the junctions is adjusted to be Mp = 10,000 ((EO)n, n = 227). The TEM image in Figure 1a[II] shows that the average size of the clusters in nanometer-scale1415. Considering the multi-reactive sites on a single AuNP, the number of incorporated PEO molecules is controlled to ×10, ×50, and ×100 times that of AuNPs (Supporting Information). A network is hardly formed if binary PEO monomers are only activated. However, highly interconnected composite clusters are formed as a result of multiple reactions of AuNP surface to thiol groups at the ends of the PEO. Multiple PEO linkages are attached to the surface of an AuNP to form networked assemblies. They also possess additional levels of complexity and anisotropy that can be exploited in self-assembly. The crosslink density (ρ) of the fully-linked network is inversely proportional to the molecular weight between the junction points (Mp).


Optimum periodicity of repeated contractile actions applied in mass transport.

Ahn S, Lee SJ - Sci Rep (2015)

(a) [I] TEM image of gold nanoparticle (AuNP) use for linterlinking. Binary functional polyethylene oxide (PEO) having EO unit number of n = 227 (2PEG 10000) is used for linking AuNPs. Representative images of the designed nanocomposites. [II] TEM, [III] X-ray nanoscopy (XN) and [IV] X-ray microscopy (XM). (b) Small angle X-ray scattering (SAXS) results of the designed AuNP-PEG nanocomposite in solution state in broad q ranges (two Sample-to-detector distance conditions are combined). A critical q value (marked by q*) exist from which temperature-responsiveness is diversified, indicating dual regions of the designed network: stable large-scale domain at low q and responsive small-scale domain at high q. Characteristic size is determined according to the temperature detected by q1 (60°C), q2 (40°C) and q3 (20°C). (c) Illustration of responsive network structures. Pore size variation of the nanocomposites in PVA matrix induced by the stimuli-responsive PEOs through which permeates are transported. [I] Swollen PEOs generates (or block) small path for permeate molecules. [II] Shrunken PEOs allow relatively wide pathway for effective permeate transport. The correlation lengths (ζ) are determined based on the pictures below. Bold lines denote stable connection, whereas dotted lines indicates flexibly responsive chains by the external stimuli.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306965&req=5

f1: (a) [I] TEM image of gold nanoparticle (AuNP) use for linterlinking. Binary functional polyethylene oxide (PEO) having EO unit number of n = 227 (2PEG 10000) is used for linking AuNPs. Representative images of the designed nanocomposites. [II] TEM, [III] X-ray nanoscopy (XN) and [IV] X-ray microscopy (XM). (b) Small angle X-ray scattering (SAXS) results of the designed AuNP-PEG nanocomposite in solution state in broad q ranges (two Sample-to-detector distance conditions are combined). A critical q value (marked by q*) exist from which temperature-responsiveness is diversified, indicating dual regions of the designed network: stable large-scale domain at low q and responsive small-scale domain at high q. Characteristic size is determined according to the temperature detected by q1 (60°C), q2 (40°C) and q3 (20°C). (c) Illustration of responsive network structures. Pore size variation of the nanocomposites in PVA matrix induced by the stimuli-responsive PEOs through which permeates are transported. [I] Swollen PEOs generates (or block) small path for permeate molecules. [II] Shrunken PEOs allow relatively wide pathway for effective permeate transport. The correlation lengths (ζ) are determined based on the pictures below. Bold lines denote stable connection, whereas dotted lines indicates flexibly responsive chains by the external stimuli.
Mentions: Citrate-stabilized colloidal gold nanoparticles (AuNPs) are prepared in aqueous solution. The concentration is adjusted to be around 2.4 × 1012 AuNPs/mL (Supporting Information)1213. The transmission electron microscopy (TEM) mage in Figure 1a[I] confirms the average diameter of the prepared single AuNP is 20 nm diameter. Binary thiol end-capped functional polyethylene oxide (PEO) are incorporated for AuNP interconnection. The molecular weight between the junctions is adjusted to be Mp = 10,000 ((EO)n, n = 227). The TEM image in Figure 1a[II] shows that the average size of the clusters in nanometer-scale1415. Considering the multi-reactive sites on a single AuNP, the number of incorporated PEO molecules is controlled to ×10, ×50, and ×100 times that of AuNPs (Supporting Information). A network is hardly formed if binary PEO monomers are only activated. However, highly interconnected composite clusters are formed as a result of multiple reactions of AuNP surface to thiol groups at the ends of the PEO. Multiple PEO linkages are attached to the surface of an AuNP to form networked assemblies. They also possess additional levels of complexity and anisotropy that can be exploited in self-assembly. The crosslink density (ρ) of the fully-linked network is inversely proportional to the molecular weight between the junction points (Mp).

Bottom Line: The characteristic repeatability and periodicity are expected to be optimized in effective system-specific functions.Optimized contractile periodicity exists for effective energy impartment to flow in a one-valve system.In the sequential contractile actions for a multi-valve system, synchronization with the fluid flow is critical for effective mass transport.

View Article: PubMed Central - PubMed

Affiliation: 1] Biofluid and Biomimic Research Center, Pohang University of Science and Technology, Pohang, 790-784, Korea [2] Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.

ABSTRACT
Dynamically repeated periodic patterns are abundant in natural and artificial systems, such as tides, heart beats, stock prices, and the like. The characteristic repeatability and periodicity are expected to be optimized in effective system-specific functions. In this study, such optimum periodicity is experimentally evaluated in terms of effective mass transport using one-valve and multi-valve systems working in contractile fluid flows. A set of nanoscale gating functions is utilized, operating in nanocomposite networks through which permeates selectively pass under characteristic contractile actions. Optimized contractile periodicity exists for effective energy impartment to flow in a one-valve system. In the sequential contractile actions for a multi-valve system, synchronization with the fluid flow is critical for effective mass transport. This study provides fundamental understanding on the various repeated periodic patterns and dynamic repeatability occurring in nature and mechanical systems, which are useful for broad applications.

No MeSH data available.