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Colloid and Polymer Science

Xiaoting Zhang, Tianyu Yuan, Hailiang Dong, Jiaming Xu, Danyue Wang, Han Tong, Xiaohuan Ji, Bin Sun, Meifang Zhu, Xiaoze Jiang
To explore block glycopolymers as novel polymeric delivery nanocarriers for anticancer drug bortezomib (BTZ), three types of block glycopolymers, poly(ethylene glycol)- block -poly(gluconamido ethyl methacrylate) (PEG113 - b -PGAMA20 ), poly(ethylene glycol)- block -poly(styrene)- block -poly(gluconamido ethyl methacrylate) (PEG113 - b -PS50 - b -PGAMA20 ), and poly(ethylene glycol)- block -poly(2-(diethyl amino) ethyl methacrylate)- block -poly(gluconamido ethyl methacrylate) (PEG113 - b -PDEA50 - b -PGAMA20 ), were synthesized via atom transfer radical polymerization (ATRP) using a PEG-based ATRP macroinitiator...
2018: Colloid and Polymer Science
Adnan Cetin, Adem Korkmaz, Ishak Bildirici
Pyrazole-3,4-dicarboxylic acid 2 was synthesized via the hydrolysis of pyrazole-3-carboxylic acid 1 and subsequently heated with thionyl chloride to give the novel pyrazole-3,4-dicarbonyl dichloride 3 , which was easily converted into oligo-pyrazole 4 upon its reaction with p -phenylene-diamine. These newly synthesized compounds were characterized by 1 H-NMR, 13 C-NMR, and FT-IR spectroscopy, and gel permission chromatography (GPC). Three novel oligo-pyrazole thin films were prepared using oligo-pyrazole 4 with these respective values of thickness: 20, 21, and 24 μm...
2018: Colloid and Polymer Science
Z Starowicz, R Wojnarowska-Nowak, P Ozga, E M Sheregii
The Surface-enhanced Raman spectroscopy is the essential tool for various levels of the molecular studies. In order to become widely used as a fast analytical tool, the enhancing structures such as the nanoparticles have to be simple, inexpensive, and offer good flexibility in enhancing properties and the spectral range. In this paper, we investigated the plasmonic properties of the metal nanoparticles, to which the molecules of interest can be adsorbed, forming the bionanocomplexes. Here, for the first time, we provided the collection of the results gathered in one article, which can serve as the basis or guidance for designing the SERS studies on different bionanocomplexes, various nanoparticle structures, sizes, and excitation wavelengths...
2018: Colloid and Polymer Science
Vinh Duy Cao, Carlos Salas-Bringas, Reidar Barfod Schüller, Anna M Szczotok, Marianne Hiorth, Manuel Carmona, Juan F Rodriguez, Anna-Lena Kjøniksen
The thermal and rheological properties of suspensions of microencapsulated phase change materials (MPCM) in glycerol were investigated. When the microcapsule concentration is raised, the heat storage capacity of the suspensions becomes higher and a slight decline in the thermal conductivity of the suspensions is observed. The temperature-dependent shear-thinning behaviour of the suspensions was found to be strongly affected by non-encapsulated phase change materials (PCM). Accordingly, the rheological properties of the MPCM suspensions could be described by the Cross model below the PCM melting point while a power law model best described the data above the PCM melting point...
2018: Colloid and Polymer Science
Ryan A Orizondo, Diane L Nelson, Mario L Fabiilli, Keith E Cook
The efficacy of inhaled antibiotics is often impaired by insufficient drug penetration into plugged and poorly ventilated airways. Liquid ventilation with perfluorocarbon (PFC) containing emulsified aqueous antibiotics, or antibacterial perfluorocarbon ventilation, could potentially improve treatment of respiratory infections when used as an adjunct therapy to inhaled antibiotics. The molecular structure and concentration of the fluorosurfactant used to stabilize such water-in-PFC emulsions will have significant effects on the efficacy and safety of the resulting treatment...
December 2017: Colloid and Polymer Science
Katharina Hauf, Kamran Riazi, Norbert Willenbacher, Erin Koos
We present a generic and versatile low temperature route to produce macro-porous bodies with porosity and pore size distribution that are adjustable in a wide range. Capillary suspensions, where the minor fluid is a monomer, are used as pre-cursors. The monomer is preferentially located between the particles, creating capillary bridges, resulting in a strong, percolating network. Thermally induced polymerization of these bridges at temperatures below 100 °C for less than 5 hours and subsequent removal of the bulk fluid yields macroscopic, self-supporting solid bodies with high porosity...
October 2017: Colloid and Polymer Science
G Kristin Jonsson, Jeanette Ulama, Malin Johansson, Malin Zackrisson Oskolkova, Johan Bergenholtz
Fluorinated spheres with grafted poly(ethylene glycol) (PEG) have been synthesized using a semi-batch emulsion polymerization in which the initiator is fed slowly to the reaction. In this way, PEG-grafted colloidal spheres can be fabricated with varying PEG chain length, different cores and varying degrees of crosslinking. The resulting batches have been characterized using disc centrifuge photosedimentometry and small-angle X-ray scattering. The size distribution is shown to be a sensitive function of the molar ratio of the reactive PEG macromonomer to fluorinated monomer, and with some optimization latices of very low polydispersity can be obtained with this simple synthesis method...
2017: Colloid and Polymer Science
S M Hosseini-Nasab, P L J Zitha
The objective of this study is to discover a synergistic effect between foam stability in bulk and micro-emulsion phase behaviour to design a high-performance chemical system for an optimized alkaline-surfactant-foam (ASF) flooding for enhanced oil recovery (EOR). The focus is on the interaction of ASF chemical agents with oil in the presence and absence of a naphthenic acid component and in situ soap generation under bulk conditions. To do so, the impact of alkalinity, salinity, interfacial tension (IFT) reduction and in situ soap generation was systematically studied by a comprehensive measurement of (1) micro-emulsion phase behaviour using a glass tube test method, (2) interfacial tension and (3) foam stability analysis...
2017: Colloid and Polymer Science
Amit Tripathi, Chunxiang Wei, Klaus Tauer
The assumption that during emulsion polymerization, the monomer molecules simply diffuse through the aqueous phase into the latex particles is a commonplace. However, there are experimental hints that this might not be that easy. Here, simulation results are discussed based on Fick's diffusion laws regarding the swelling of latex particles. The results of quantitative application of these laws for swelling of latex particles allow the conclusion that the instantaneous replenishment of the consumed monomer during emulsion polymerization requires a close contact between the monomer and the polymer particles...
2017: Colloid and Polymer Science
Giuseppe Lazzara, Richard A Campbell, Solmaz Bayati, Kaizheng Zhu, Bo Nyström, Tommy Nylander, Karin Schillén
The thermal responsive behavior of adsorbed layers of diblock copolymers of poly(N-isopropylacrylamide) (PNIPAAM) and poly((3-acrylamidopropyl)trimethylammonium chloride) (PAMPTMA(+)) with γ-cyclodextrin (γ-CD) at the solid/liquid interface has been investigated using three in situ techniques: null ellipsometry, quartz-crystal microbalance with dissipation monitoring, and neutron reflectometry. The measurements provided information about the adsorbed amounts, the layer thickness, hydration and viscoelastic properties, and the interfacial structure and composition...
2017: Colloid and Polymer Science
Anna M Szczotok, Manuel Carmona, Anna-Lena Kjøniksen, Juan F Rodriguez
The adsorption of polyvinylpyrrolidone (PVP) by the thermoregulating microcapsules has been studied. The mass ratio of PVP has been changed from 1 to 20, with respect to the lowest amount of PVP value (4.08 g). The results confirmed that a large amount of PVP was adsorbed by the polymeric shell. Experimental data were perfectly fitted by Langmuir model, obtaining at a confidence level of 95% values of 192.9 ± 0.4 g/kg and 0.18 ± 0.11 m(3)/kg for the maximum adsorption capacity and the equilibrium constant, respectively...
2017: Colloid and Polymer Science
Jessica A Bonham, Franceska Waggett, Malcolm A Faers, Jeroen S van Duijneveldt
Non-aqueous microgel particles are commonly synthesised in water, dried, and then redispersed in non-aqueous solvents. An important factor to consider when synthesising such particles is the initiator, which can determine how well the particles disperse in solvents. Polystyrene microgel particles were made with three different initiators. When a neutral, oil soluble initiator (azobisisobutyronitrile) was used the particles dispersed in toluene as well as cyclohexane and decalin. In contrast, anionic, water-soluble initiators (potassium persulfate or azobis(4-cyanovaleric acid)) created particles that only redispersed in toluene and not the other two solvents...
2017: Colloid and Polymer Science
Stanislaw Jung, Aneta Petelska, Piotr Beldowski, Wayne K Augé, Tahlia Casey, Dominik Walczak, Krzysztof Lemke, Adam Gadomski
This mini review is focused on the emerging nexus between the medical device and pharmaceutical industries toward the treatment of damaged articular cartilage. The physical rationale of hyaluronic acid and phospholipid preparations as tribological surgical adjuvants for repaired articular cartilage surfaces is explored, with directions for possible new research which have arisen due to the therapeutic advance of the physiochemical scalpel. Because synovial joint lubrication regimes become dysfunctional at articular cartilage lesion sites as a result of the regional absence of the surface active phospholipid layer and its inability to reform without surgical repair, hyaluronic acid and phospholipid intra-articular injections have yielded inconsistent efficacy outcomes and only short-term therapeutic benefits mostly due to non-tribological effects...
2017: Colloid and Polymer Science
Anna Mozrzymas
The molecular connectivity indices were used to derive the simple model relating the critical micelle concentration of cationic (chloride) gemini surfactants to their structure. One index was selected as the best to describe the effect of the structure of investigated compounds on critical micelle concentration consistent with the experimental results. This index encodes the information about molecular size, the branches, and also the information about heteroatoms. The selected model can be helpful in designing novel chloride gemini surfactants...
2017: Colloid and Polymer Science
Björn Lindman
Surfactants have been the basis for applications in several industrial sectors for a long time. However, fundamental research was 50 years ago still limited to a small number of academic groups and even basic aspects were controversial. The field has since undergone an enormous expansion and the improved understanding has laid the basis of numerous new products as well as been the basis of important parts of nano-science and -technology.The present author has during 50 years in academia devoted most of his research to amphiphilic compounds, including both surfactants and polymers...
2016: Colloid and Polymer Science
Małgorzata Wiśniewska, Stanisław Chibowski, Teresa Urban, Dariusz Sternik, Konrad Terpiłowski
The stability mechanism and thermal properties of the system alumina-anionic polyacrylamide (PAM) was studied. The polymer's adsorption properties in dependence on the following parameters solution pH (in the range 3-9), temperature (in the range 15-35 °C), and carboxyl groups' content in the PAM chains (in the range 5-30 %) were examined. The turbidimetry method was applied for determination of the suspension stability of alumina in the presence of PAM. The obtained results indicate that the polymer addition improves significantly Al2O3 suspension stability at pH 6 and 9 (in the whole examined temperature range)...
2016: Colloid and Polymer Science
Aleksandra Szcześ
After an hour contact with a phospholipase A2 (PLA2) solution, only the outer leaflet of the dipalmitoylphosphatidylcholine (DPPC) bilayers supported on mica surface underwent hydrolysis whose products, i.e., palmitic acid and lysophospholipid, accumulated on the bilayer surface. Only calcite was present on the bare mica and enzymatically unmodified and modified supported DPPC bilayers soaked for 2 weeks at 25 and 37 °C in a solution of initial pH equals to 7.4 and 9.2 containing calcium and bicarbonate ions at their concentrations about those of human blood plasma...
2016: Colloid and Polymer Science
Sławomir Drozdek, Urszula Bazylińska
The present work is focused on the long-term stability and in vitro cellular internalization of newly designed biocompatible polyester nanocapsules prepared via nanoprecipitation approach with mean diameter <165 nm and narrow size distribution, dedicated to theranostic applications. We monitored the optical, morphological, and biological properties of the nanocarriers loaded by multifunctional cargo, i.e., paclitaxel (PTX) and a fluorescent marker: coumarin-6 (CR-6) or Nile Red (NR), by fluorescence and UV-vis spectroscopy (encapsulation efficiency), dynamic light scattering (average size expressed as hydrodynamic diameter, D H), zeta potential (ζ, colloidal stability), atomic force microscopy (AFM, imaging), and confocal laser scanning microscopy (CLSM, nanocapsule visualization, and cellular internalization in vitro by human breast cancer MCF-7/WT cells)...
2016: Colloid and Polymer Science
Jens Meissner, Albert Prause, Bhuvnesh Bharti, Gerhard H Findenegg
The adsorption of lysozyme and ß-lactoglobulin onto silica nanoparticles (diameter 21 nm) was studied in the pH range 2-11 at three different ionic strengths. Since the two proteins have a widely different isoelectric point (pI), electrostatic interactions with the negative silica surface lead to a different dependence of adsorption on pH. For lysozyme (pI ≈ 11), the adsorption level increases with pH and reaches a value corresponding to about two close-packed monolayers at pH = pI. In the multilayer adsorption region near pI, added electrolyte causes a decrease in adsorption, which is attributed to the screening of attractive interactions between protein molecules in the first and second adsorbed layer...
2015: Colloid and Polymer Science
K Kang, J K G Dhont
Concentrated dispersions of highly charged rod-like colloids (fd-virus particles) in isotropic-nematic coexistence exhibit a dynamical state when subjected to low-frequency electric fields [Soft Matter, 2010, 6, 273]. This dynamical state consists of nematic domains which persistently melt and form on time scales typically of the order of seconds. The origin of the dynamical state has been attributed to a field-induced, cyclic dissociation and association of condensed ions [Soft Matter, 2014, 10, 1987, Soft Matter, 2015, 11, 2893]...
2015: Colloid and Polymer Science
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