A Way to Predict Gold Nanoparticles/Polymer Hybrid Microgel Agglomeration Based on Rheological Studies

In this work, a detailed rheological study of hybrid poly(acrylamide-co-acrylic acid) P(AAm-co-AAc) aqueous microgel dispersions is performed. Our intention is to understand how the presence of gold nanoparticles, AuNP, embedded within the microgel matrix, affects the viscoelastic properties, the colloidal gel structure formation, and the structure recovery after cessation of the deformation of the aqueous microgel dispersions. Frequency sweep experiments confirmed that hybrid microgel dispersions present a gel-like behavior and that the presence of AuNP content within microgel matrix contributes to the elasticity of the microgel dispersions. Strain sweep test confirmed that hybrid microgels aqueous dispersion also form colloidal gel structures that break upon deformation but that can be recovered when the deformation decreases. The fractal analysis performed to hybrid microgels, by applying Shih et al. and Wu and Morbidelli’s scaling theories, evidenced that AuNP significantly affects the colloidal gel structure configuration ending up with the formation of agglomerates or microgel clusters with closer structures in comparison to the reference P(AAm-co-AAc) aqueous microgel dispersions.

Download Full-text

UCST Responsive Microgels of Poly(acrylamide−acrylic acid) Copolymers: Structure and Viscoelastic Properties

Macromolecules ◽

10.1021/ma901316k ◽

2009 ◽

Vol 42 (22) ◽

pp. 9118-9123 ◽

Cited By ~ 49

Author(s):

Coro Echeverria ◽

Daniel López ◽

Carmen Mijangos

Keyword(s):

Acrylic Acid ◽

Viscoelastic Properties ◽

Poly Acrylamide

Download Full-text

A facile synthesis of thermo-responsive Au–polymer hybrid microgels through temperature-induced co-aggregation and self-crosslinking

Polymer Chemistry ◽

10.1039/c5py00774g ◽

2015 ◽

Vol 6 (33) ◽

pp. 5989-5992 ◽

Cited By ~ 5

Author(s):

Xiang Chen ◽

Jiao-Tong Sun ◽

Cai-Yuan Pan ◽

Chun-Yan Hong

Keyword(s):

Facile Synthesis ◽

Polymer Hybrid ◽

Hybrid Microgels

A facile temperature-induced co-aggregation and self-crosslinking (TICASC) method was developed for preparing thermo-responsive Au–polymer hybrid microgels.

Download Full-text

Force modeling to develop a novel method for fabrication of hollow channels inside a gel structure

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411919891654 ◽

2019 ◽

Vol 234 (2) ◽

pp. 223-231 ◽

Cited By ~ 2

Author(s):

Ranjit Barua ◽

Himanshu Giria ◽

Sudipto Datta ◽

Amit Roy Chowdhury ◽

Pallab Datta

Keyword(s):

Viscoelastic Material ◽

Biomedical Engineering ◽

Viscoelastic Properties ◽

Three Dimensional ◽

Microfluidic Devices ◽

Robotic Arm ◽

Complex Geometries ◽

Gel Structure ◽

Force Modeling ◽

Novel Method

Fabrication of hollow channels with user-defined dimensions and patterns inside viscoelastic, gel-type materials is required for several applications, especially in biomedical engineering domain. These include objectives of obtaining vascularized tissues and enclosed or subsurface microfluidic devices. However, presently there is no suitable manufacturing technology that can create such channels and networks in a gel structure. The advent of three-dimensional bioprinting has opened new possibilities for fabricating structures with complex geometries. However, application of this technique to fabricate internal hollow channels in viscoelastic material has not been yet explored to a great extent. In this article, we present the theoretical modeling/background of a proposed manufacturing paradigm through which hollow channels can be conveniently fabricated inside a gel structure. We propose that a tip connected to a robotic arm can be moved in X-, Y-, and Z-axis as per the desired design. The tip can be moved by a magnet or mechanical force. If the tip is further trailed with porous tube and moved inside the viscoelastic material, corresponding internal channels can be fabricated. To achieve this, however, force modeling to understand the forces that will be required to move the tip inside viscoelastic material should be known and understood. Therefore, in our first attempt, we developed the computational force modeling of the tip movement inside gels with different viscoelastic properties to create the channels.

Download Full-text

Hybrid Microgels Containing Gold Nanoparticles

nano Online ◽

10.1515/nano.0013.00008 ◽

2016 ◽

Author(s):

Andrij Pich ◽

Arpita Karak ◽

Yan Lu ◽

Anup K. Ghosh ◽

Hans-Juergen P. Adler

Keyword(s):

Gold Nanoparticles ◽

Hybrid Microgels

Download Full-text

Kinetic Approach to Elucidate Size Controllable Features in Nanocomposites of Gold Nanoparticles and Poly(3,4-ethylenedioxythiophene) in Aqueous Dispersion Stabilized by Gum Acacia

The Journal of Physical Chemistry C ◽

10.1021/jp508326j ◽

2014 ◽

Vol 118 (44) ◽

pp. 25756-25764 ◽

Cited By ~ 8

Author(s):

Igor Rocha ◽

Emili Lucht ◽

Izabel C. Riegel-Vidotti ◽

Marcio Vidotti ◽

Elisa S. Orth

Keyword(s):

Gold Nanoparticles ◽

Aqueous Dispersion ◽

Kinetic Approach ◽

Gum Acacia

Download Full-text

Hybrid Microgels Containing Gold Nanoparticles

e-Polymers ◽

10.1515/epoly.2006.6.1.226 ◽

2006 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Andrij Pich ◽

Arpita Karak ◽

Yan Lu ◽

Anup K. Ghosh ◽

Hans-Juergen P. Adler

Keyword(s):

Gold Nanoparticles ◽

Sodium Citrate ◽

Colloidal Stability ◽

Nano Particles ◽

Composite Particles ◽

Temperature Sensitive ◽

Chloroauric Acid ◽

Gold Nano Particles ◽

Hybrid Microgels

AbstractIn present paper we report on a preparation of hybrid microgels filled with gold nano-particles (AuNPs). Temperature-sensitive VCL/AAEM microgels have been used as containers for deposition of Au by in situ formation of gold nano-particles. Synthesis of AuNPs has been performed by two methods: a) reduction of chloroauric acid with sodium borhydride and b) reduction of chloroauric acid by sodium citrate under ultrasonic agitation. In both cases AuNPs were deposited directly into microgels leading to formation of composite particles which exhibit temperature-sensitive properties, tunable gold contents and high colloidal stability. The influence of Au load on microgel size, morphology, swellingdeswelling behaviour and stability is discussed.

Download Full-text

Design of artificial membrane transporters from gold nanoparticles with controllable hydrophobicity

Faraday Discussions ◽

10.1039/c6fd00037a ◽

2016 ◽

Vol 191 ◽

pp. 495-510 ◽

Cited By ~ 6

Author(s):

Marcin P. Grzelczak ◽

Alexander P. Hill ◽

Domagoj Belic ◽

Dan F. Bradley ◽

Casper Kunstmann-Olsen ◽

...

Keyword(s):

Gold Nanoparticles ◽

Phase Transfer ◽

Aqueous Dispersion ◽

Bilayer Membrane ◽

Phospholipid Bilayer ◽

Potassium Ions ◽

Vesicle Membrane ◽

Ligand Shell ◽

Phospholipid Bilayer Membrane ◽

Liquid Systems

Gold nanoparticles with variable hydrophobicity have been prepared in three different size regimes following established methods. The control of hydrophobicity was achieved by complexation of the 18-crown-6-CH2-thiolate ligand shell with potassium ions. Potassium dependent phase transfer of these particles from dispersion in water to chloroform was demonstrated, and the equilibrium partitioning of the particles in water–chloroform liquid/liquid systems was quantified by optical spectroscopy. The gradual complexation of the ligand shell with potassium ions was further monitored by zeta potential measurements. Potassium dependent insertion of nanoparticles into the phospholipid bilayer membrane of vesicles in aqueous dispersion has been demonstrated by cryogenic transmission electron microscopy (cryo-TEM). Nanoparticle-dependent potassium ion transport across the vesicle membrane has been established by monitoring the membrane potential with fluorescence spectroscopy using a potential sensitive dye.

Download Full-text

Impact of Viscoelastic Characteristics of Oil Based Muds/Synthetic Based Muds on Cuttings Settling Velocities

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology ◽

10.1115/omae2017-62129 ◽

2017 ◽

Cited By ~ 1

Author(s):

M. C. Altindal ◽

E. Ozbayoglu ◽

S. Miska ◽

M. Yu ◽

N. Takach ◽

...

Keyword(s):

Aging Time ◽

Viscoelastic Properties ◽

Settling Velocity ◽

Drilling Fluid ◽

Time Dependent ◽

Drilling Fluids ◽

Structure Development ◽

Gel Structure ◽

Fluid Characterization ◽

Fluid Characteristics

Inaccurate calculation of settling and slip velocities of cuttings leads to inaccurate determination of cuttings concentration and, hence, borehole pressure, as well as inaccurate lag times. To minimize these problems, an understanding of the relation between drilling fluid characteristics and the cuttings transport process is essential. It is desirable for drilling fluids to form a gel structure to help cuttings transportation and suspension of solids. The gel structure development is proportional to increase in aging time. The increase in aging time yields higher shear stress responses at a constant rate of deformation to the drilling fluid sample. The gel structure development helps keep cuttings in suspension and shows a viscoelastic response to small deformations. Understanding these viscoelastic responses is important in rheological characterization and settling velocity prediction. Thus, viscoelastic drilling fluid characteristics should be investigated in depth to better estimate settling and slip velocities of cuttings and to increase cutting transport efficiency. The main focus of this project is to work on viscoelastic and time-dependent fluid characterization to identify the relation between rheological properties and settling velocities of cuttings. Rheological experiments were conducted using an Anton Paar Physica MCR 301 Rheometer. Three different drilling fluids, Water Based Mud (WBM), Oil Based Mud (OBM) and Synthetic Based Mud (SBM), are used for rheological and settling velocity experiments. Stress Overshoot Tests (SOTs) and Steady-Shear experiments were performed to investigate viscoelastic properties and gel structure of the fluids, and to examine time and temperature dependence of WBM, OBM and SBM. Information obtained from the viscoelastic and time-dependent fluid characterization tests was coupled with settling velocity data using both arbitrary shape of cuttings and spherical particles. A mathematical model that considers viscoelastic properties and time dependency of drilling fluids was developed to estimate settling and slip velocities of the cuttings. Comparisons between the proposed models and existing models based on standard rheological measurements were also done. The results show that the proposed model has good agreement with the experimental data.

Download Full-text

Effect of maleimide-functionalized gold nanoparticles on hybrid biohydrogels properties

RSC Advances ◽

10.1039/c5ra06806a ◽

2015 ◽

Vol 5 (62) ◽

pp. 50268-50277 ◽

Cited By ~ 18

Author(s):

C. García-Astrain ◽

I. Ahmed ◽

D. Kendziora ◽

O. Guaresti ◽

A. Eceiza ◽

...

Keyword(s):

Gold Nanoparticles ◽

Viscoelastic Properties ◽

Cross Linking ◽

Nanocomposite Hydrogels ◽

Functionalized Gold Nanoparticles

Nanoparticle cross-linking. Nanocomposite hydrogels with remarkable viscoelastic properties are prepared using maleimide coated gold nanoparticles as co cross-linkers for furan modified gelatin.

Download Full-text