Superstructure-dependent optical and electrical properties of an unusual face-to-face, pi-stacked, one-dimensional assembly of dehydrobenzo[12]annulene in the crystalline state

To develop a novel pi-conjugated molecule-based supramolecular assembly, we designed and synthesized trisdehydrotribenzo[12]annulene ([12]DBA) derivative 2 with three carboxyl groups at the periphery. Recrystallization of 2 from DMSO gave a crystal of the solvate 23 DMSO. Crystallographic analysis revealed, to our surprise, that a face-to-face pi-stacked one-dimensional (1D) assembly of 2 was achieved and that the DMSO molecule played a significant role as a "structure-dominant element" in the crystal. This is the first example of [12]DBA to stack completely orthogonal to the columnar axis. To reveal its superstructure-dependent optical and electrical properties, 2 and its parent molecule 1, which crystallizes in a herringbone fashion, were subjected to fluorescence spectroscopic analysis and charge-carrier mobility measurements in crystalline states. The 1D stacked structure of 2 provides a red-shifted, broadened, weakened fluorescence profile (lambda(max) = 545 nm, phi(F) = 0.01), compared to 1 (lambda(max) = 491 nm, phi(F) = 0.12), due to strong interactions between the p orbitals of the stacked molecules. The charge-carrier mobility of the single crystal of 23 DMSO, as well as 1, was determined by flash photolysis time-resolved microwave conductivity (FP-TRMC) measurements. The single crystal of 23 DMSO revealed significantly-anisotropic charge mobility (sigma(mu) = 1.5x10(-1) cm(2) V(-1) s(-1)) along the columnar axis (crystallographic c axis). This value is 12 times larger than that along the orthogonal axis (the a axis).     

Polymerization of Blending Cholesteryl Acrylate and Methyl Phenyl Benzoyl Acrylate

Liquid crystal is a material which is between solid and liquid phase and commonly called mesophase. Blends of liquid crystal are of great interest because of their unique optical properties. Blending in this study using two monomers of liquid crystal were cholesteryl acrylate and methyl phenyl benzoyl acrylate. The polymerization process using uv curing techniques by irradiation UV ray and without irradiation UV ray. Polymerization of blending liquid crystal acrylate using initiator 2-hydroxy-2-methyl-1-phenylpropane. Based on peak at GPC curve of polymerization by irradiation UV ray, type of that polymer is copolymer. Therefore the polymerization without UV ray, type of that polymer is homopolymer. SEM images of liquid crystal acrylate polymer showed lamella chain models that are characteristic of a polymer chains. Type of polymer liquid crystal acrylate was the type of Side Chain Liquid Crystalline Polymers (SCLCPs). Therefore acrylate polymer liquid crystal in this research has semi-crystalline phase, which contained crystalline phase and amorphous phase on the XRD pattern. The results of FT-IR spectroscopic characterization of the two monomers showed a peak at the wave number of 1600.43 cm ^-1 and 1622.86 cm^-1 which indicates a double bond (C=C) were obtained from acrylation. While the spectroscopy on the product blending the wave number of the peak regions is reduced that shows that carbon double bonds (C=C) in the acrylate group has polymerized. It also strengthened with a very sharp peak for CC functional groups on the wave number of 2855.15 cm^-1. The results of this study indicate that the liquid crystal polymer acrylic polymerization results with radiation UV ray and without UV ray, respectively absorb light in the UV wavelength region 363 nm and 351 nm.     

Fabrication of high-aspect-ratio poly(2-hydroxyethyl methacrylate) brushes patterned on silica surfaces by very-large-scale integration process

We used a novel fabricated process including electron beam and isotropic oxygen plasma to generate signal line patterns of polymerized 2-hydroxyethyl methacrylate (HEMA) on patterned Si(1 0 0) surfaces. Isotropic oxygen plasma was introduced to enhance the resolutions of the line and dots patterns of the PHEMA brush are approached to 350 nm and 2 μm, respectively. We established the surface grafting polymerization kinetics of the PHEMA chains on silicon surface by to fit the thickness and number-average molecular weight (M(n)). The propagation rate (k(p)) and active grafting specie deactivation rate (k(d)) lies in the range of ~3.6 × 10(-2) s(-1) M(-1) and 4.8 × 10(-5) s(-1), respectively. The measured thicknesses by ellipsometer and analyzed M(n) of "free" PHEMA by gel permeation chromatography (GPC) are fitted well by the polymerization kinetic model. In addition, aspect-ratios (height/width) are used to define the shape of patterned PHEMA brushes. The high-aspect-ratio of the PHEMA brush line with width of 350 nm is 0.27. We use a graft polymerization/solvent immersion method for generating various patterns of polymer brushes to investigate the deformation of the PHEMA brush through aspect-ratios.     

Fabrication of block copolymer brushes on hollow sphere surface via reverse iodine transfer polymerization

The block copolymer brushes grafted from hollow sphere surface via reverse iodine transfer polymerization (RITP) were investigated in this work. A sufficient amount of azo initiator was introduced onto hollow sphere surface firstly. Then the monomer methyl methacrylate (MMA) was polymerized via surface-initiated reverse iodine transfer polymerization (RITP) using azo group modified hollow sphere as initiator. The microstructure of the samples was characterized by FT-IR, (1)H NMR, respectively. Results indicated that the poly(methyl methacrylate) (PMMA) with end functionality of alkyl iodine group had grafted from hollow sphere surface. TEM observations showed that the average diameter of hollow core was central at 1.3-1.4 μm and the average wall thickness increased from 103 nm to 138 nm and 172 nm after grafting polymerization of MMA and Tb complex, respectively. The closely linear plots of molecular weight (M(n)) versus conversion, linear kinetic plots for the free polymer formed in solution and the ability to extend the chains by sequential addition of monomer indicated that the RITP was a controlled process with a "living" characteristic.     

Clicked (AB)2C‐type miktoarm terpolymers: Synthesis,thermal and self‐assembly properties,and preparation of nanoporous materials

A well‐defined (PEO‐PS)₂‐PLA miktoarm terpolymer ( 1 ) was synthesized by stepwise click reactions of individually prepared poly(ethylene oxide) (PEO), polystyrene (PS, polymerized by atom transfer radical polymerization), and polylactide (PLA, polymerized by ring‐opening polymerization) blocks. As characterized by differential scanning calorimetry and small‐angle X‐ray scattering techniques, the terpolymer self‐assembled into a hexagonal columnar structure consisting of PLA/PEO cylindrical cores surrounded by PS chains. In contrast, the ion‐doped sample ( 1‐Li⁺ ) with lithium concentration per ethylene oxide = 0.2 exhibited a three‐phase lamellar structure, which was attributed to the microphase separation between PEO and PLA blocks and to the conformational stabilization of the longest PLA chain. The two‐phase columnar morphology before the ion doping was used to prepare a nanoporous material. PLA chains in the cylindrical core region were hydrolyzed by sodium hydroxide, producing nanopores with a pore diameter of about 14 nm. The resulted nanoporous material sank to the bottom in water, because of water‐compatible PEO chains on the walls. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Controlling dimensions of polymerized micelles: micelle template versus reaction conditions

The polymerization of elongated micellar structures offers a novel approach to the production of high aspect ratio, water-soluble amphiphilic nanoparticles. Three different surfactants were synthesized consisting of a cationic surfactant of the form (C(X)H(2X+1))trimethylammonium (where X = 14, 16, or 18) and a vinyl-containing counterion, 4-vinylbenzoate. The resulting polymer-surfactant aggregates have been polymerized to produce high aspect ratio nanoparticles which are insensitive to changes in solution conditions. The radius of the initial template is maintained on polymerization, whereas the template length is not. The aggregate radius is varied by changing the length of the surfactant tail, in this case producing aggregates with radii of 1.7, 2.0, or 2.4 nm. Variation of the initiator decomposition half-life, by means of using different initiators and varying temperature, is used to control the aggregate length between 80 and 500 nm. Through the process discussed here, both the radius and length of the aggregates are controlled independently.     

Characterization of rodlike aggregates generated from a cationic surfactant and a polymerizable counterion

The polymerization of elongated micellar structures offers a novel approach to the production of high-aspect-ratio, water-soluble amphiphilic nanorods. A cationic surfactant with a vinyl-containing counterion, cetyltrimethylammonium 4-vinylbenzoate, has been synthesized and polymerized to produce high-aspect-ratio nanoparticles which are insensitive to changes in solution conditions. Aggregates are polymerized over a range of initiator concentrations allowing for control of the product length. Small-angle neutron scattering and light scattering are used to characterize the dimensions of the polymerized aggregates, showing them to have a fixed radius of 2 nm and contour lengths varying from 96 to 340 nm. Proton NMR verifies the chemical structure and provides insight into the mobility of the aggregate components. Finally, gel permeation chromatography of the polymer extracted from the aggregates indicates that the polymerization reaction controls the aggregate dimensions.     

Mirror helices and helicity switch at surfaces based on chiral triangular-shape oligo(phenylene ethynylenes)

The self‐assembly of triangular‐shaped oligo(phenylene ethynylenes) (OPEs), peripherally decorated with chiral and linear paraffinic chains, is investigated in bulk, onto surfaces and in solution. Whilst the X‐ray diffraction data for the chiral studied systems display a broad reflection centered at 2θ ～20° (λ=Cu_Kα), the higher crystallinity of OPE 3 , endowed with three linear decyl chains, results in a diffractrogram with a number of well‐resolved reflections that can be accurately indexed as a columnar packing arranged in 2D oblique cells. Compounds (S)‐ 1 a and (R)‐ 1 b —endowed with (S)‐ and (R)‐3,7‐dimethyloctyloxy chains—transfer their chirality to the supramolecular structures formed upon their self‐assembly, and give rise to helical nanostructures of opposite handedness. A helicity switch is noticeable for the case of chiral (S)‐ 2 decorated with (S)‐2‐methylnonyloxy chains which forms right‐handed helices despite it possesses the same stereoconfiguration for their stereogenic carbons as (S)‐ 1 a that self‐assembles into left‐handed helices. The stability and the mechanism of the supramolecular polymerization in solution have been investigated by UV/Vis experiments in methylcyclohexane. These studies demonstrate that the larger the distance between the stereogenic carbon and the aromatic framework is, the more stable the aggregate is. Additionally, the self‐assembly mechanism is conditioned by the peripheral substituents: whereas compounds (S)‐ 1 a and (R)‐ 1 b self‐assemble in a cooperative manner with a low degree of cooperativity, the aggregation of (S)‐ 2 and 3 is well described by an isodesmic model. Therefore, the interaction between the chiral coil chains conditions the handedness of the helical pitch, the stability of the supramolecular structure and the supramolecular polymerization mechanism of the studied OPEs.     

Polymerization and decomposition of terephthaloyl chloride and p-phenylenediamine at 500 °C

In order to synthesize the high temperature solid lubricating film by gas-phase polymerization at 500?°C with two kinds of gasified monomers for use in airplane and rocket engines, the polymerizing activity of terephthaloyl chloride (TPC) and p-phenylenediamine (PPD) at 500?°C and their polymerized product poly-p-phenyleneterephthamide (PPTA) as well as its decomposed solid residues were researched. It was proved by FT-IR and ¹HNMR on the solid residues after the 10?min experiment of the both monomers in muffle furnace at 500?°C and PPTA synthesized by conventional method that at 500?°C the polymerization tendency of these monomers should trump their decomposition tendency. The solid residues after the 10?min experiment mainly consisted of polymerized products which would decline as the experimental period increases, while the content of decomposed and carbonized products would raise. FT-IR and elemental analysis revealed a similar structure of the solid residues after the both monomers or PPTA calcined for 60?min at 500?°C, which further demonstrated the polymerized products would degrade, decompose and carbonize after the prophase polymerization. Finally, effects of experimental temperature and monomers molar ratio on amounts and structures of the solid residues were discussed to propose preliminary mechanisms of polymerization and decomposition.     

Hydrogel behavior of a sugar-based gelator by introduction of an unsaturated moiety as a hydrophobic group

The new sugar-based gelators 1 and 2 were synthesized, and their gelation abilities were evaluated in organic solvents and in water. Compound 1 gelates both water and organic solvents whereas 2 gelates only organic solvents. Superstructural difference between hydrogel 1 and organogel 2 was investigated by CD, TEM, AFM, 1H NMR and XRD. Hydrogel 1 displays a well-developed helical ribbon structure with 20-150 nm diameter and a length of several hundred microm whereas organogel 2 shows a twisted fiber structure of diameter 20 nm. CD measurements of hydrogel 1 and organogel 2 indicate that hydrogel 1 maintains a well-ordered chiral structure whereas organogel 2 maintains a relatively disordered chiral structure. The 1H NMR and XRD results suggest that the hydrophobic interaction in hydrogel 1 are relatively weak, with a relatively small region interdigitated between lipophilic alkyl groups. In addition, upon irradiation at 254 nm wavelength, hydrogel 1 reveals a red coloration at 540 nm. These results indicate that the self-assembled hydrogel 1 was polymerized by UV-irradiation. The intensity of the CD spectrum of the polymerized hydrogel markedly decreased. This result indicates that upon polymerization the highly ordered chiral structure of hydrogel 1 changes to a disordered molecular packing structure.     

Self‐Assembly of Coronene Bisimides: Mechanistic Insight and Chiral Amplification

The study of the organization of small π‐conjugated molecules is imperative to understanding and controlling its properties for various applications. Coronene bisimides (CBIs) are potential candidates for novel liquid‐crystalline materials and active n‐type semiconductor molecules in organic electronics. To understand the self‐assembly of this seldom‐studied chromophore, we have designed two derivatives of CBIs bearing chiral and achiral 3,4,5‐trialkoxyphenyl groups at the imide position, named as CBI‐GCH and CBI‐GACH , respectively. CBI‐GCH self‐assembles mainly through π‐stacking and van der Waals interactions in nonpolar methylcyclohexane to result in long 1D fibrillar stacks. The mechanism of supramolecular polymerization was probed by using chiroptical studies, which showed an isodesmic pathway for CBI‐GCH . The thermodynamic parameters that govern the self‐assembly are detailed. CBI‐GACH also shows similar self‐assembly behavior as its chiral counterpart. X‐ray diffraction studies of both molecules reveals a 2D hexagonal columnar arrangement. The coassembly of CBI‐GCH and CBI‐GACH shows chiral amplification (sergeant and soldiers experiment) with saturation at 30–50 % of the chiral derivative, which was further used to study the dynamics of the assembly. Thus, this study presents a rare report of chiral amplification in an isodesmic system.     

The Cyclic Hydrogen‐Bonded 6‐Azaindole Trimer and its Prominent Excited‐State Triple‐Proton‐Transfer Reaction

The compound 6‐azaindole undergoes self‐assembly by formation of N(1)?H???N(6) hydrogen bonds (H bonds), forming a cyclic, triply H‐bonded trimer. The formation phenomenon is visualized by scanning tunneling microscopy. Remarkably, the H‐bonded trimer undergoes excited‐state triple proton transfer (ESTPT), resulting in a proton‐transfer tautomer emission maximized at 435 nm (325 nm of the normal emission) in cyclohexane. Computational approaches affirm the thermodynamically favorable H‐bonded trimer formation and the associated ESTPT reaction. Thus, nearly half a century after Michael Kasha discovered the double H‐bonded dimer of 7‐azaindole and its associated excited‐state double‐proton‐transfer reaction, the triply H‐bonded trimer formation of 6‐azaindole and its ESTPT reaction are demonstrated.     

Self-assembly and UV-curing Property of Polymerized Lyotropic Liquid Crystal Monomer of Sodium 3,4,5-tris(11 acryloxyundecyloxy)benzoate

A polymerized lyotropic liquid crystal monomer of sodium 3,4,5-tris(11-acryloxyundecyloxy)-benzoate was synthesized by a convenient route starting from 3,4,5-trihydroxybenzoic acid via esterification followed by etherification, acylation and finally neutralization. The chemi-cal structure was confirmed by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance spectral analysis. The self-organization behavior of the monomer with deionized water in methanol at room temperature was also demonstrated. The assemblies were char-acterized by polarized optical microscope and X-ray diffraction. The results show that a solution containing 80:20 of the monomer to water was found to be able to self-organize into Lamellar (La) phase and 92:8 with inverted hexagonal (H_II) phase, which was in ac-cordance with the theoretical calculation of critical packing parameter. It suggests that the concentration of the monomer was the key factor to influence assembly structure. Addi-tionally, the acrylate conversion with different photoinitiators and nanostructure retention after polymerization were investigated. The research shows that the acrylate conversion of the monomer with Darocur2959 could reach up to 78% when irradiated by 30 mW/cm² UV light of 365 nm for 30 min characterized by Real-time FT-IR as well as the sol-gel method. Meanwhile, the La and H_II phase nanostructures were both retained after polymerization.     

Chiral Amplification during Asymmetric‐Induced Copolymerization of Phenylacetylenes with Tight Cis‐Cisoidal Main Chains

A novel phenylacetylene ( 1 ) having two hydroxyl groups and a chiral pinanyl group together with the other three related phenylacetylenes has been synthesized and (co)polymerized by using an achiral catalytic system. Among the four monomers, only 1 is suitable to the asymmetric‐induced polymerization ( AIP ). Chiral amplification phenomenon is only observed in the copolymerization of 1 with an achiral phenylacetylene having two hydroxyl groups ( 3 ). The tight helical cis‐cisoidal main chain formed by making intramolecular hydrogen bonds between the hydroxyl groups in the copoly( 1 / 3 ) enhances the efficiency of chiral induction and as a result chiral amplification phenomenon is observed during the copolymerization.

     

Unraveling the mechanism of nanotube formation by chiral self-assembly of amphiphiles

The self-assembly of nanotubes from chiral amphiphiles and peptide mimics is still poorly understood. Here, we present the first complete path to nanotubes by chiral self-assembly studied with C(12)-β(12) (N-α-lauryl-lysyl-aminolauryl-lysyl-amide), a molecule designed to have unique hybrid architecture. Using the technique of direct-imaging cryo-transmission electron microscopy (cryo-TEM), we show the time-evolution from micelles of C(12)-β(12) to closed nanotubes, passing through several types of one-dimensional (1-D) intermediates such as elongated fibrils, twisted ribbons, and coiled helical ribbons. Scattering and diffraction techniques confirm that the fundamental unit is a monolayer lamella of C(12)-β(12), with the hydrophobic tails in the gel state and β-sheet arrangement. The lamellae are held together by a combination of hydrophobic interactions, and two sets of hydrogen-bonding networks, supporting C(12)-β(12) monomers assembly into fibrils and associating fibrils into ribbons. We further show that neither the "growing width" model nor the "closing pitch" model accurately describe the process of nanotube formation, and both ribbon width and pitch grow with maturation. Additionally, our data exclusively indicate that twisted ribbons are the precursors for coiled ribbons, and the latter structures give rise to nanotubes, and we show chirality is a key requirement for nanotube formation.     

Stabilization of a kinetically favored nanostructure: surface ROMP of self-assembled conductive nanocoils from a norbornene-appended hexa-peri-hexabenzocoronene

Newly designed norbornene-appended hexabenzocoronene 1 self-assembles, upon diffusion of an Et(2)O vapor into its CH(2)Cl(2) solution, to form either graphitic nanocoils or nanotubes, depending on the self-assembling conditions. The coiled assembly, selectively formed at 15 degrees C, is a kinetic intermediate for the tubular assembly and transforms into nanotubes on standing at 25 degrees C. However, post-ring-opening metathesis polymerization of the norbornene pendants of 1 enhances the thermal stability of the coiled assembly as well as the tubular one and disables a thermodynamic coil-to-tube transition. The polymerized nanocoils show an electroconductivity of 1 x 10(-)(4) S cm(-)(1) upon doping with I(2), while the nonpolymerized nanocoils are disrupted upon being doped.     

Diketopyrrolopyrrole Columnar Liquid‐Crystalline Assembly Directed by Quadruple Hydrogen Bonds

A diketopyrrolopyrrole (DPP) dye self‐assembles via a unique hydrogen‐bonding motif into an unprecedented columnar liquid‐crystalline (LC) structure. X‐ray and polarized FTIR experiments reveal that the DPPs organize into a one‐dimensional assembly with the chromophores oriented parallel to the columnar axis. This columnar structure is composed of two π–π‐stacked DPP dimers with mirror‐image configurations that stack alternately through quadruple hydrogen bonding by 90° rotation. This exotic packing is dictated by the complementarity between H‐bonds and the steric demands of the wedge‐shaped groups attached at the core. This novel LC supramolecular material opens a new avenue of research on DPP dye assemblies with photofunctional properties tailored by H‐bonding networks.     

Screw-sense-selective polymerization of aryl isocyanides initiated by a Pd-Pt mu-ethynediyl dinuclear complex: a novel method for the synthesis of single-handed helical poly(isocyanide)s with the block copolymerization technique

Living polymerization of chiral aryl isocyanides, such as m- and p-menthoxycarbonylphenyl isocyanides 2 and 5, initiated by the Pd-Pt mu-ethynediyl dinuclear complex 1, proceeds with a high screw-sense selectivity to give the poly(isocyanide)s 3 and 6, which exhibit a large specific rotation and an intense CD band at lambda = 364 nm as a consequence of a helical chirality. The molar optical rotation and molar circular dichroism of the resulting polymers 3 and 6 reach a constant value at a degree of polymerization (Pn) of more than 30. Screw-sense-selective polymerization of achiral aryl isocyanides that bear very bulky substituents, such as 3,5-di(propoxycarbonyl)phenyl isocyanide (11), 3,5-di(butoxycarbonyl)phenyl isocyanide (13), and 3,5-di(cyclohexyloxycarbonyl)phenyl isocyanide (15), is achieved by the use of chiral oligomer complexes 3(30) and 6(30), prepared from the reaction of 1 with 30 equivalents of 2 or 5, as an initiator to give predominantly single-handed helical polymers. In contrast, smaller aryl isocyanides are also polymerized by 3(30) and 6(30) with screw-sense selectivity in the initial stage of the reaction, but the single-handed helix is not preserved up to high molecular weight. Kinetic studies of the polymerization of (L)- and (D)-2, or (L)- and (D)-5 with chiral oligomer complexes (L)-3(50) or (L)-6(100) suggests that the screw sense of the polymer backbone is not controlled kinetically, but rather that the thermodynamically stable screw sense is produced.     

Raman spectroelectrochemical study of Meldola blue, adsorbed and electropolymerized at a gold electrode

Surface-enhanced Raman spectroscopy (SERS) was used to probe the structure of adsorbed and electropolymerized Meldola blue (MB) films on roughened gold surfaces in solutions with pH 1.0 and 7.0 by using 785 nm excitation wavelength. Spectral bands were assigned based on density functional theory (DFT) calculations at B3LYP/6-311+G(2d, p) level. The most characteristic band of the oxidized MB form was found to be the breathing vibration of the central ring containing heteroatoms at 596 cm(-1). Based on a red shift of bands assigned to vibrations of double C=N(C(2)H(6)) bonds and adjacent ring C=C bonds in surface spectra as compared with solution 1 it was suggested that polymerization and interaction with an electrode surface proceed through these moieties. The presence of out-of-plane bands in SERS spectra was attributed to "flat" or slightly "tilted" orientation of aromatic rings at the interface. Potential-dependent spectral changes were followed by SERS spectroscopy. Raman spectra of the reduced MB form were obtained in both pH 1.0 and pH 7.0 solutions by analysis of the potential-difference SERS spectra. Reduced MB form can be recognized by characteristic bands near 1620, 1574, 1374, and 1234 cm(-1). By comparing the intensities of 1637 cm(-1) (oxidized MB form) and 1374 cm(-1) (reduced MB form) bands in experimental spectra of polymerized MB in pH 1.0 solution, a reduction-induced decrease by factor of 7 was estimated. A similar tendency in intensity changes showed calculations indicating that this effect is associated with reduction-induced changes in the molecular structure of the dye.     

Characterization of Plasma-Polymerized 4-vinyl Pyridine with Silver Nanoparticles on Poly(ethylene terephthalate) Film for Anti-Microbial Properties

4-vinyl pyridine was polymerized on poly(ethylene terephthalate) (PET) film by using lower energy pulsed AC plasma under low pressure in Ar atmosphere. The plasma polymerized coating was characterized by ATR Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Different thicknesses of poly(4-vinyl pyridine) coating under different plasma polymerization conditions were studied. Silver nanoparticles with diameter around 50nm deposit were precipitated on the poly(4-vinyl pyridine) coating by UV irradiation in Silver nitride water solution, in order to enhance the anti-microbial properties. Different kinds of modified PET films were tested for anti-microbial properties against yeast (Debaryomyces hansenii) by using microbiological analyser µ-4200 and direct microscopic count method.