Evaluation of interfacial tension for poly(methyl methacrylate) and polystyrene by rheological measurements and interaction parameter of the two polymers

Y. T. Sung,김우년,W. J. Seo,Y. H. Kim,이헌상 한국유변학회 2004 Korea-Australia rheology journal Vol.16 No.3

Morphological and rheological properties of the poly(methyl methacrylate) (PMMA) and polystyrene (PS) blends were studied by scanning electron microscopy (SEM) and advanced rheometric expansion system (ARES). From the SEM results, the PMMA-PS blends showed dispersed morphology and the particle size of the dispersed phase was quite small (0.1∼0.6 m) compared with other immiscible polymer blends. Values of the interfacial tension of the PMMA-PS blend were obtained from the Choi-Schowalter and the Palierne emulsion models using the storage modulus of the PMMA and PS, and found to be 1.0 and 2.0 mN/m, respectively. The interfacial tension between the PMMA and PS was also calculated from the Flory-Huggins polymer-polymer interaction parameter () and found to be from 0.98 to 1.86 mN/m depending on the molecular weight and composition. Comparing the values of the interfacial tension from the Flory-Huggins polymer-polymer interaction parameter and the values measured by oscillatory rheometer, it is suggested that the interfacial tension of the PMMA-PS blend obtained from the polymer-polymer interaction parameter are in good agreement with the values obtained by rheological measurements.

Coupling of breath figure method with interfacial polymerization: Bottom-surface functionalized honeycomb-patterned porous films

Male, Umashankar,Shin, Bo Kyoung,Huh, Do Sung Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

<P><B>Abstract</B></P> <P>A new and facile method was designed for the fabrication of asymmetrically polyaniline (PANI) functionalized polystyrene (PS) honeycomb-patterned porous films in a single step. The method involves the coupling of breath figure process with an interfacial polymerization, wherein the PS solution containing benzoyl peroxide in an organic solvent was cast under humid conditions over an aqueous solvent containing aniline and methane sulfonic acid. PANI was coated on the bottom surface at the organic/aqueous interface by an interfacial polymerization method, whereas a porous patterned PS was fabricated on the top surface by the breath figure method. The films revealed a translucent insulating PS top surface and a conducting green PANI bottom surface. The obtained films represented asymmetrical composition, color, morphology, conductivity, and contact angle on either surface.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First report on asymmetric functionalized honeycomb patterned films. </LI> <LI> Film was obtained by coupling interfacial polymerization with breath figure process. </LI> <LI> It has asymmetrical color, composition, morphology, contact angle and conductivity. </LI> <LI> These can be used in applications where asymmetrical property is a requirement. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Evaluation of interfacial tension for poly(methyl methacrylate) and polystyrene by rheological measurements and interaction parameter of the two polymers

Sung, Y.T.,Seo, W.J.,Kim, Y.H.,Lee, H.S.,Kim, W.N. The Korean Society of Rheology 2004 Korea-Australia rheology journal Vol.16 No.3

Morphological and rheological properties of the poly(methyl methacrylate) (PMMA) and polystyrene (PS) blends were studied by scanning electron microscopy (SEM) and advanced rheometric expansion system (ARES). From the SEM results, the PMMA-PS blends showed dispersed morphology and the particle size of the dispersed phase was quite small (0.1~0.6 $\mu\textrm{m}$ compared with other immiscible polymer blends. Values of the interfacial tension of the PMMA-PS blend were obtained from the Choi-Schowalter and the Palierne emulsion models using the storage modulus of the PMMA and PS, and found to be 1.0 and 2.0 mN/m, respectively. The interfacial tension between the PMMA and PS was also calculated from the Flory-Huggins polymer-polymer interaction parameter ($\chi$) and found to be from 0.98 to 1.86 mN/m depending on the molecular weight and composition. Comparing the values of the interfacial tension from the Flory-Huggins polymer-polymer interaction parameter and the values measured by oscillatory rheometer, it is suggested that the interfacial tension of the PMMA-PS blend obtained from the polymer-polymer interaction parameter are in good agreement with the values obtained by rheological measurements.

Star polymer-assembled thin film composite membranes with high separation performance and low fouling

Jeon, Sungkwon,Park, Chan Hyung,Park, Sang-Hee,Shin, Min Gyu,Kim, Hyun-Ji,Baek, Kyung-Youl,Chan, Edwin P.,Bang, Joona,Lee, Jung-Hyun Elsevier 2018 Journal of membrane science Vol.555 No.-

<P><B>Abstract</B></P> <P>Thin film composite (TFC) membranes have attracted intense interest due to applications in various molecular separation processes including water purification, gas separation, organic solvent separation and saline-gradient energy production. In particular, growing global demands for clean water and reduced energy consumption have raised interest in highly permselective and low fouling TFC membranes for water treatment and desalination. This drive has led to the design of new molecular structures of TFC membranes using advanced materials. Here, we designed a new building block material, a star-shaped polymer, which can be assembled into the selective layer of the TFC membrane <I>via</I> a commercial interfacial polymerization (IP) technique. This ideal 3-dimensional compact globular geometry along with high density end-functional groups enabled the realization of membranes with higher permselectivity as well as superior antifouling properties even compared to commercial membranes. We demonstrate the remarkable versatility of this building block by using the same starting materials to fabricate membranes that can function either as nanofiltration or reverse osmosis membrane depending on the IP process conditions, which is not feasible with the conventional materials used in membrane fabrication.</P> <P><B>Highlights</B></P> <P> <UL> <LI> TFC membranes were fabricated by interfacial polymerization of star polymers (SP). </LI> <LI> RO and NF performances can be obtained by adjusting the polymerization conditions. </LI> <LI> SP assembly produces a highly permselective layer with a unique stratified structure. </LI> <LI> SP-assembled membranes show separation performance exceeding commercial membranes. </LI> <LI> SP-assembled membranes have superior fouling resistance to commercial membranes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Dielectric characteristics of MXene-incorporated polymer composites

Jun So-Yeon,Yu SeGi 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.11

Polymer-based dielectric composites were developed by mixing barium titanium oxide (BaTiO3, BTO) with conducting two-dimensional nanomaterials called MXenes in a polymer matrix. MXene platelets were delaminated, or exfoliated, in dimethyl sulfoxide (DMSO) solvent using ultrasonication for varying length of time (0, 1, 2, and 3 h). The addition of conducting MXene platelets induced interfacial polarization and resulted in improved dielectric performance compared to the reference sample, with an increase in the dielectric constant of 12 ~29% and a low level of the dielectric loss of less than 0.06 at 1 kHz. Among the samples, the sample produced with 2 h of sonication time, rather than the longest time of 3 h, was found to have the best by balancing ultrasonication’s dual efects: delamination of individual MXene platelets and the breaking up of platelets into smaller pieces. A longer sonication time failed to suppress the dielectric loss, despite its high value in the dielectric constant, potentially due the formation of a percolative connection among numerous small MXene platelets generated by the severe sonication. Thus, careful optimization of MXene delamination is necessary by monitoring sonication time to prevent the disintegration of MXene platelets into numerous small ones.

Influences of nanoparticles aggregation/agglomeration on the interfacial/interphase and tensile properties of nanocomposites

Zare, Yasser,Rhee, Kyong Yop,Hui, David Elsevier Science Ltd 2017 Composites Part B, Engineering Vol.122 No.-

<P><B>Abstract</B></P> <P>In this article, the roles of nanoparticles aggregation/agglomeration in the interfacial/interphase and tensile properties of polymer nanocomposites are discussed. The interfacial/interphase and tensile levels are quantitatively characterized in some samples using known models assuming the aggregation/agglomeration phenomena by the effective volume fraction of nanoparticles. The findings show that the nanoparticles aggregation/agglomeration significantly reduces the interfacial/interphase and tensile properties of nanocomposites via decreasing the specific surface area and effective volume fraction of nanoparticles. Additionally, Kerner and Paul models suggest the accurate predictions compared to the experimental data considering the aggregated/agglomerated nanoparticles. However, assumption of well-dispersed nanoparticles over-predicts the modulus in the reported samples.</P>

Polyacetylene-based polyelectrolyte as a universal interfacial layer for efficient inverted polymer solar cells

Nam, Sungho,Seo, Jooyeok,Song, Myeonghun,Kim, Hwajeong,Ree, Moonhor,Gal, Yeong-Soon,Bradley, Donal D.C.,Kim, Youngkyoo ELSEVIER 2017 ORGANIC ELECTRONICS Vol.48 No.-

<P><B>Abstract</B></P> <P>Here we report that poly(N-dodecyl-2-ethynylpyridiniumbromide) (PDEPB) interlayers between electron-collecting zinc oxide (ZnO) layers and bulk heterojunction (BHJ) layers act as a universal interfacial layer for improving the performances of inverted-type polymer:fullerene solar cells. Three different BHJ layers, poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C<SUB>61</SUB>-butyric acid methyl ester (PC<SUB>61</SUB>BM), poly[(4,8-bis(2-ethylhexyloxy)-benzo[1,2-b:4,5-b']dithiophene)-2,6-diyl-alt-(N-2-ethylhexylthieno[3,4-<I>c</I>]pyrrole-4,6-dione)-2,6-diyl]] (PBDTTPD):PC<SUB>61</SUB>BM, and poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-<I>b</I>]-thiophenediyl] (PTB7) and [6,6]-phenyl-C<SUB>71</SUB>-butyric acid methyl ester (PC<SUB>71</SUB>BM), were employed so as to prove the role of the PDEPB interlayers. Results showed that the power conversion efficiency (PCE) of polymer:fullerene solar cells with the three different BHJ layers increased in the presence of the PDEPB interlayers prepared from 0.5 mg/ml solutions. The improved PCE was attributed to the conformal coating of the PDEPB layers on the ZnO layers (by atomic force microscopy measurement), lowered work functions of ZnO induced by the PDEPB layers (by Kelvin probe measurement), and reduced interface resistance (by impedance spectroscopy measurement), as supported by the noticeable change in the atom environments of both the ZnO and PDEPB layers (by X-ray photoelectron spectroscopy measurement).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polyacetylene-based polyelectrolyte interlayers improve device performances. </LI> <LI> The polyacetylene interlayers work for various active layer materials. </LI> <LI> The ZnO surface defects can be effectively reduced by the polyacetylene interlayers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effects of Size and Aggregation/Agglomeration of Nanoparticles on the Interfacial/Interphase Properties and Tensile Strength of Polymer Nanocomposites

Ashraf, Muhammad Aqeel,Peng, Wanxi,Zare, Yasser,Rhee, Kyong Yop Springer US 2018 NANOSCALE RESEARCH LETTERS Vol.13 No.1

<P>In this study, several simple equations are suggested to investigate the effects of size and density on the number, surface area, stiffening efficiency, and specific surface area of nanoparticles in polymer nanocomposites. In addition, the roles of nanoparticle size and interphase thickness in the interfacial/interphase properties and tensile strength of nanocomposites are explained by various equations. The aggregates/agglomerates of nanoparticles are also assumed as large particles in nanocomposites, and their influences on the nanoparticle characteristics, interface/interphase properties, and tensile strength are discussed. The small size advantageously affects the number, surface area, stiffening efficiency, and specific surface area of nanoparticles. Only 2 g of isolated and well-dispersed nanoparticles with radius of 10 nm (<I>R</I> = 10 nm) and density of 2 g/cm<SUP>3</SUP> produce the significant interfacial area of 250 m<SUP>2</SUP> with polymer matrix. Moreover, only a thick interphase cannot produce high interfacial/interphase parameters and significant mechanical properties in nanocomposites because the filler size and aggregates/agglomerates also control these terms. It is found that a thick interphase (<I>t</I> = 25 nm) surrounding the big nanoparticles (<I>R</I> = 50 nm) only improves the <I>B</I> interphase parameter to about 4, while <I>B</I> = 13 is obtained by the smallest nanoparticles and the thickest interphase.</P>

계면중합법에 의한 폴리아마이드 박막복합분리막 제작에 있어 유기용매 점도의 영향

박철호(Chul Ho Park) 한국고분자학회 2016 폴리머 Vol.40 No.6

계면중합법은 나노두께의 선택층(분리막)을 용액상에서 만들 수 있어 다양한 응용분야에 적용되고 있다. 분리막 성능은 반응에 참여하는 단량체 종류뿐만 아니라, 계면중합 조건에 따라 변화한다. 본 연구에서는 유기용매 점도가 분리막 형성 및 성능에 어떤 영향을 주는지 알아보고자 하였다. 점도 영향을 관찰하기 위해 유기상에 n-hexane, light mineral oil, heavy mineral oil을 사용하였다. 계면중합에 트리메조일 로라이드(trimesoyl chloride, TMC)와 메타페닐렌다이아민(m-phenylenediamine, MPD)을 사용하여 담수화용 폴리아마이드 복합분리막을 제작하였다. 0.2 wt% 소금물을 사용하여 15 bar에서 물투과도 및 염배제율을 측정하여 분리막 성능을 평가하였다. 가장 높은 염배제율을 보이는 비율은 1:10 w/w% TMC/MPD이었다. 동일한 농도비에서 농도가 증가할수록 물투과도는 감소하는 반면 염배 제율은 증가하였다. 저점도 n-hexane 고점도 mineral oil을 사용할 경우 TMC 농도가 낮을수록, MPD 농도는 높을수록 분리막이 형성되지 않았다. 이들 조건에서, TMC의 아실클로이드(acyl chloride)는 모두 반응에 참여하여 말단의 아민기들과 충분한 네트워크를 만들기 위해 새로운 TMC 공급이 필요할 것이다. 하지만, 고점도 유기상에서는 TMC 확산속도가 느리기 때문에 주워진 계면중합 시간 동안 공급이 원활하지 않아 분리막이 만들어지지 않았을 것이다. Interfacial polymerization has been used for various applications because it can synthesize a nanometer scale selective layers via a solution process. The performance of membrane depends on the type of reactive monomers as well as reaction conditions. This study focuses on how the viscosity of organic phase affects the performance of the corresponding thin film composite (TFC) membrane. To investigate the effect of viscosity, three different types of organic solvents including n-hexane, light/heavy mineral oils were used. Trimesoyl chloride (TMC) and m-phenylenediamine (MPD) were selected for monomers in the organic and the aqueous phase, respectively, to produce TFC membranes for desalination. The membrane was characterized by measuring the water permeability and the salt rejection by using 0.2 wt% NaCl feed solution at 15 bar and 25 oC. The highest salt rejection was achieved by using a TMC/MPD ratio of 1:10 w/w%. At this concentration ratio, the water permeability decreases with increasing the concentration, while the salt rejection increases. When mineral oil is used for the organic phase, there exist certain conditions at which the formation of TFC membranes failed. It is most likely because high viscosity substantially reduces the diffusion rate of TMC, inhibiting TMC monomers from reacting with MPD monomers during interfacial polymerization.

Efficient PEDOT:PSS-Free Polymer Solar Cells with an Easily Accessible Polyacrylonitrile Polymer Material as a Novel Solution-Processable Anode Interfacial Layer

Noh, Yong-Jin,Park, Sae-Mi,Yeo, Jun-Seok,Kim, Dong-Yu,Kim, Seok-Soon,Na, Seok-In American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.45

<P>We demonstrate that an easily accessible polyacrylonitrile (PAN) polymer can efficiently function as a novel solution-processable anode interfacial layer (AIL) to boost the device performances of polymer:fullerene-based solar cells (PSCs). The PAN thin film was simply prepared with spin-coating of a cost-efficient PAN solution dissolved in dimethylformamide on indium tin oxide (ITO), and the thin polymeric interlayer on PSC parameters and stability were systemically investigated. As a result, the cell efficiency of the PSC with PAN was remarkably enhanced compared to the device using bare ITO. Furthermore, with PAN, we finally achieved an excellent power conversion efficiency (PCE) of 6.7% and a very high PSC stability in PTB7:PC<SUB>71</SUB>BM systems, which constitute a highly comparable PCE and superior device lifetime relative to those of conventional PSCs with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). These results demonstrate that the inexpensive solution-processed PAN polymer can be an attractive PEDOT:PSS alternative and is more powerful for achieving better cell performances and lower cost PSC production.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-45/acsami.5b07841/production/images/medium/am-2015-078415_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b07841'>ACS Electronic Supporting Info</A></P>