Cationic fluorinated polyacrylate core‐shell latex with pendant long chain alkyl: Synthesis,film morphology,and its performance on cotton substrates

We synthesized a novel cationic fluorinated polyacrylate latex (FLDH) with pendant long chain alkyl by copolymerization of perfluoroalkyl ethyl acrylate, lauryl methacrylate, dimethylaminoethyl methacrylate, and 2‐hydroxypropyl acrylate. FTIR, ¹H‐NMR, TEM, DSC, and TGA were used to characterize the as‐prepared FLDH. Then fine morphology, components, and hydrophobicity of films on silicon wafer and cotton substrates were investigated by scanning electron microscope, field emission scanning electronic microscope, atomic force microscope, X‐ray photoelectron spectroscopy (XPS), contact angle meter, etc. Results showed that the FLDH particles had quasi‐spherical core‐shell structure with an average diameter of 144 nm. The core‐shell FLDH film thus had two T_g and its thermal property was improved compared to fluorine‐free acrylate latex. FLDH could form a film on both the cotton fiber and silicon wafer substrate. At an amplification of <60,000 (of the original fiber) and the observation rule (working distance) of >100 nm, FLDH showed a smooth resin film on the treated fabric/fiber surface. However, as the observation rule decreased to 2 nm‐almost a molecular lever‐the FLDH film mostly exhibited an inhomogeneous structure and uneven morphology in its atomic force microscope images. There were many low or high peaks in FLDH topography. Consequently, in 5 μm² scanning field, the root mean square roughness of FLDH film reached to 0.506 nm. XPS analysis indicated the perfluoroalkyl groups had the tendency to enrich at the surface. In addition, water contact angle of the treated fabric could attain 146.2°. FLDH do not influence whiteness of the treated fabric but will make it slightly stiff at high doses. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013     

A functional polysiloxane with benzophenone derivative ultraviolet absorbing side groups: Synthesis,morphology, and its performance on fabrics

A novel functional polysiloxane (PSBP) bearing benzophenone derivatives as UV absorbing side groups was synthesized by hydrosilylation of polyhydromethylsiloxane (PHMS) with 2‐hydroxy‐4‐(β‐hydroxy‐γ‐allyloxy)propyloxy benzophenone (HHAPB). The chemical structure, film morphology, and the softening fabric property of the synthesized polysiloxane were characterized and investigated by spectrum analysis, atomic force microscope (AFM), and Kawabata evaluation system. The experiment results indicated that PSBP was not only an excellent polymeric UV‐absorber, which showed intensive ultraviolet absorptions respectively, at wavelengths of 243.2, 288.2, and 325.4 nm, but could exhibit a nonhomogeneous, some rough structure film on silicon wafer substrate. In addition, the functional side group, benzophenone derivative as well as its mass ratio to PSBP has an influence on the performance of the synthesized polysiloxane. As the mass ratio decreased from 31.48 to 12.87%, the molar extinction coefficients ε_max (λ_max = 288.2 nm) of the PSBP fluids lowered from 3.4564 × 10⁵ to 1.5763 × 10⁵, but while the softening fabric properties of PSBP on cotton fabrics increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 680–687, 2007     

长链羧基聚硅氧烷的膜形貌、乳化及其应用性能

运用场发射扫描电镜(FESEM)及原子力显微镜(AFM)对十二烷基/羧基改性聚硅氧烷(RCAS)成膜形貌进行观测,测试结果表明,RCAS可在纤维表面形成均匀平整的有机硅膜,该膜使原有纤维表面沟壑、块状物消失;RCAS在单晶硅表面形成微观非均一相硅膜,表面粗糙,在扫描高度为5 nm、扫描范围为2μm×2μm条件下,可观察到膜表面存在许多竖直的尖峰。考察RCAS乳液及与氨基硅乳共混乳液在棉纤维织物上的应用性能,测试结果表明,织物经RCAS乳液及共混乳液整理后,柔软性能较之空白织物均提升;且随着RCAS乳液含量的增加,共混乳液整理织物的白度和亲水性提升,柔软性能下降。     

Synthesis of dimethyldodecyl quaternary ammonium polyether polysiloxane and its film morphology and performance on fabrics

A novel comb‐like polysiloxane (QPEPS) bearing dimethyldodecyl quaternary ammonium polyether groups (QPEs) was synthesized by reaction of epoxy polyether polysiloxane, which was prepared from polymethylhydrosiloxane (PHMS) and allyl polyether epoxy (APEE500) via hydrosilylation, with N,N‐dimethyldodecylamine (DMDA) in the presence of acetic acid (HAc). Chemical structure, film morphology, and performance of the synthesized polysiloxane on cotton and its mimic substrates were investigated by Fourier transform infrared spectrum, nuclear magnetic resonance spectrum, field emission scanning electron microscopy, atomic force microscopy, and so on. As expected, the QPEPS was easily emulsified into a clear, uniform micro‐emulsion with a mean size of about 20 nm. Since the presence of a large number of cationic QPEs pendant in the side chains, the QPEPS exhibited microscopic inhomogeneous morphology with many pinnacles projected on the film surface. As a result, the root mean square roughness (Rq) of the QPEPS film reached 0.615 nm in 2 µm × 2 µm scanning field and the largest height of the pinnacles achieved 7.618 nm. And under the influence of the QPEs, the QPEPS provided the treated fabrics with not only very soft handle, but also excellent hygroscopicity. And the wettability of the treated fabrics reached 1–3 s. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40612.     

Synthesis,film morphology,and performance on cotton substrates of dodecyl/piperazine functional polysiloxane

A novel polysiloxane bearing dodecyl and epoxy side groups (DESO) was synthesized as an intermediate through hydrosilylation of polymethylhydrosiloxane with allyl glycidyl ether and 1‐dodecene. Then, dodecyl/piperazine functional polysiloxane (DPSO) was prepared through the reaction of N‐aminoethylpiperazine with DESO. The chemical structure of DPSO was characterized with FTIR and ¹H‐NMR spectroscopy and its application performance on cotton fabrics was studied. DPSO with dodecyl side groups gifted the treated fabrics with good wettability and whiteness compared with piperazine functional polysiloxane, while with a slightly reduced softness as well as thickening handle. Film morphology, orientation, and performance on cotton substrates of DPSO were investigated by scanning electron microscope, atomic force microscopy, X‐ray photoelectron microscope, and so on. Affected by the dodecyl side groups, DPSO formed relatively hydrophilic, macroscopically smooth but actually uneven films with many dodecyl side chain pillars on the treated substrate surfaces. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40186.     

Fabrication of superhydrophobic fabric coating using microphase‐separated dodecafluoroheptyl‐containing polyacrylate and nanosilica

Superhydrophobic coating was developed on cotton fabric in this article using a dodecafluoroheptyl‐containing polyacrylate (DFPA) and nanosilica. Film morphology of DFPA on cotton fibers/fabrics and chemical compositions of the treated cotton fabric were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS), respectively. DFPA could form a relatively even film on the cotton fabric/fiber under SEM observation; however, it presented a rough and microphase‐separated pattern under AFM observation. There were many mountain‐like protuberances. The height of the protuberances and the root mean square roughness (R_ms) of the film reached about 20–50 nm and 12.511 nm in 2 × 2‐μm² scanning field (as the scale data was 100 nm). XPS analysis indicated that the perfluoroalkyl groups had the tendency to enrich at the film–air interface. DFPA could make the treated cotton fabric with a water contact angle (WCA) at about 138.5°. Cotton fabric was previously roughened using a 1 wt % silica sol with an average particle size of 20–30 nm and then finished by DFPA; hydrophobicity of the resultant cotton fabric was strongly improved, and WCA could reach 153.6°. The color of this superhydrophobic fabric would not be influenced, but its softness decreased compared to untreated fabric. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of N‐β‐aminoethyl‐γ‐aminopropyl polydimethyl‐co‐polydiphenylsiloxane and its film morphology and orientation

A fabric softener, N‐β‐aminoethyl‐γ‐aminopropyl polydimethyl‐co‐polydiphenylsiloxane (PASO), was synthesized by the polymerization of octamethyl cyclotetrasiloxane with an amino‐functional silane and dimethyldiphenylsilane. The chemical structure of the synthesized polysiloxane was characterized by Fourier transform infrared and ¹H‐NMR spectra. The morphology, composition, and hydrophobic properties of the PASO film were investigated by X‐ray photoelectron spectroscopy, atomic force microscopy, contact angle measurement, and other measurements. The experimental results indicate that on the silicon wafer surface, PASO formed a hydrophobic, nonhomogeneous structural film. In addition, the atomic force microscopy results show that the PASO film deposited on the silicon wafer seemed to be slightly rougher than the film of the control, the N‐β‐aminoethyl‐γ‐aminopropyl polydimethylsiloxane. As a result, an orientation model of PASO is proposed on the basis of the characterization of the PASO film properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The effect of argon on the electron field emission properties of α-C:N thin films

Amorphous carbon nitride (α-C:N) thin films were synthesized on silicon as electron emitters by the electron cyclotron resonance chemical vapor deposition (ECR-CVD) system in which a negative dc bias was applied to the graphite substrate holder and a mixture of C₂H₂ and N₂ was used as precursors. The addition of Ar combined with the application of a negative dc bias can increase nitrogen content (N/C) measured by X-ray photoelectron spectroscopy (XPS), eliminate the dangling bonds in the film determined by Fourier transform infrared (FTIR) spectroscopy, decrease the film thickness measured by field emission scanning electron microscope (FE-SEM), increase the film roughness measured by atomic force microscope (AFM) and raise the graphitic content examined by Raman spectroscopy. The result shows that the onset emission field of α-C:N with Ar addition to the precursors can be as low as 4.5 V μm⁻¹ compared with 9.5 V μm⁻¹ of the film without the addition of Ar.     

Synthesis of nanocrystalline diamond films using microwave plasma CVD

Diamond is one of the most valuable materials for the industrial applications because of its excellent properties including high hardness, with good electrical insulation and thermal conductivity. Mechanical polishing processes of diamond are difficult and very costly. To limit those costs, it is reasonable to think that the surface roughness of the as-grown diamond film should be as small as possible. In this study, a nanocrystalline diamond film was synthesized on a 4-inch Si wafer at 923 K and methane concentration of 10 vol.%, (H₂/CH₄=100/10 sccm) using a microwave plasma CVD system. In order to increase the nucleation density, the substrate was pretreated by dry scratch method with diamond powder of two sizes (250 nm and 5 nm). The nucleation density was approximately 1×10¹¹ cm⁻². The grown diamond films were analyzed by Raman spectroscopy and X-ray diffraction (XRD). The grain size was observed to be approximately 10 nm by FE-SEM observation. Surface roughness was measured as Rms=8.4 nm by atomic force microscope (AFM). The as-grown properties of those nanocrystalline diamond films were almost efficient for tribological and the optical applications.     

Synthesis and characterization of novel ultraviolet‐curing polyurethane acrylate/epoxy acrylate/SiO2 hybrid materials via sol–gel reaction

A series of ultraviolet‐curable hybrid materials was first synthesized here by sol–gel process based on tetraethoxysilane (TEOS) and polyurethane acrylate/epoxy acrylate resin. The functional groups in the hybrid materials were investigated by infrared spectroscopy (IR) analysis. The crystallinity of the hybrid materials and polymer resin was examined by X‐ray diffraction. Then, nearly uniform dispersion of SiO₂ particles with the diameters ?100 nm were revealed by field emission scanning electron micrographs. The surface morphology was scanned by atomic force microscope. And, thermal stability was measured by thermogravimetric analysis for hybrid materials produced from different mass ratio of TEOS to polymer. The results show that the hybrid material from the mass ratio of TEOS to polymer of 0.4 : 1 performed desirable optimal thermal stability and uniform microstructure which is suitable for optical fiber coating in high temperature application. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Electrochemical properties of ferrocene modified polysiloxane/chitosan nanocomposite and its application to glucose sensor

A ferrocene functionalized polysiloxane was synthesized and its composite with chitosan was prepared. The electrochemical properties in solution and in immobilized states were examined for both the ferrocene functionalized polysiloxane and its composite with chitosan. The composite film exhibits a reversible redox wave at E°′ = +360 mV vs. Ag/AgCl which is 110 mV more negative than that of the ferrocene functionalized polysiloxane film. It can be explained by the introduction of chitosan to enhance the hydrophilicity of the film and increase mass transport rate in aqueous condition. The composite film shows a very facile electron transport behavior with an apparent diffusion coefficient of 3.5 × 10⁻⁶ cm²/s. The scanning electron microscopic analysis of the film, which is in dried state, reveals that the ferrocene polysiloxane forms average 500 nm size spheres and those are evenly distributed in the chitosan matrix to give a homogeneous nanocomposite. The significantly large value of the apparent diffusion coefficient of the ferrocene moieties in the composite film can be explained by the introduction of highly hydrophilic character to the film originated from the high water-uptake capability of chitosan to give solution-like behaviors of the film in solution. The composite is found to be a useful platform to host enzymes to make biosensors and glucose sensing capability is demonstrated.     

碳纤维结构的常用表征技术

本文结合近几年的研究报道,归纳了决定碳纤维性能及应用的两个方面内部体结构和表面结构的一些常用表征技术。碳纤维聚集态的表征主要通过X-射线衍射（广角、小角）、电子衍射;碳纤维形态结构特征常用透射电子显微镜;碳纤维表面结构的表征方法有扫描电子显微镜（SEM）,原子力显微镜（ArM）,扫描隧道显微镜（STM）以及扫描力显微镜（SFM）。其中,SEM能够看到整个纤维的表面形貌,而AFM、STM、SFM用于表面几个纳米到几百个纳米范围的形貌分析。此外,表面化学状态（表面成分、表面官能团）表征主要依靠X光电子能谱。     

Annealing effect upon chain orientation, crystalline morphology, and polarizability of ultra-thin P(VDF-TrFE) film for nonvolatile polymer memory device

The ferroelectric behavior of spin-cast ultra-thin P(VDF-TrFE) (72-28) film is highly influenced by sample preparation methods including thermal annealing. The effect of sample preparation methods on the surface morphology, chain and dipole orientation, ferroelectric properties, and nonvolatile memory characteristics were studied using FTIR-grazing incident reflection absorption spectroscopy (GIRAS), grazing incident wide angle X-ray diffraction (GIWAXD), atomic force microscope (AFM), dynamic contact electrostatic force microscope (DC-EFM), and polarization-electric field (P-E) hysteresis measurements to find the feasibility of applying the ultra-thin P(VDF-TrFE) film to scanning probe microscopy (SPM)-based storage device or low-cost nonvolatile ferroelectric polymer random access memory (NvFePoRAM) device. From the collective analysis of GIRAS, GIWAXD, and AFM data, annealing the as-cast sample at temperature (ca. 120 °C) above Curie transition, but below its melting transition temperature was found to be the most suitable condition to fabricate the NvFePoRAM and/or SPM-based storage device with a memory density of about 30 GB/in². DC-EFM technique was successfully used to characterize the nonvolatile memory properties by ‘writing and erasing’ the data bit through applying a dc bias voltage much larger than coercive voltage with different polarities and then reading the data bit by applying a high frequency ac voltage of only 2 V to the ‘written or erased’ area.     

Development of the scratch resistance on acrylic sheet with basic colloidal silica (SiO2)—methyltrimethoxysilane (MTMS) nanocomposite films by sol–gel technique

The formation of scratch‐resistant coating film prepared from colloidal silica and a polysiloxane matrix was investigated. Methyltrimethoxysilane (MTMS) was hydrolysed and mixed with silica sol (SiO₂) at various compositions to form the hybrid hard‐coating nanocomposite film. The hydrolysed MTMS (polysiloxane) acts as the polymeric binder that is covalently linked to the colloidal silica surface and provides adhesion for the scratch resistant coating film to the substrate. The ratio between the polymeric matrix and the SiO₂ nanoparticles was found to play a major role in controlling the coating film appearance and its resistance to scratching. At a SiO₂ content < 30 wt.%, the agglomeration of the hydrolysed polysiloxane was observed and caused the opacity of the coating film. At a SiO₂ content >70 wt.%, there was not enough polysiloxane to act as a binder for the SiO₂, therefore a shrinkage upon solidification of the coating film caused cracking within the nanocomposite film. The optimum ratio was found to be at 40 wt.% ≤SiO₂ ≤60 wt.%, where the films had a transparent, crack free hard coating, with excellent scratch resistance, good adhesion and very good environmental resistance. The nanoindentation revealed that the nanocomposite film, at the optimum loading, possessed a higher strength with a higher SiO₂ loading. Film properties, including hardness, scratch resistance, adhesion and environmental resistance were also examined. The morphology of nanocomposite films was identified by atomic force microscopy (AFM) and scanning electron microscopy (SEM). © 2011 Canadian Society for Chemical Engineering     

丙交酯/己内酯聚酯共聚物在天然海水中水解行为研究

熔融共聚法制备了丙交酯/己内酯聚酯共聚物,采用FT-IR、1H-NMR和XRD等分析手段对聚酯共聚物进行了结构表征,确认合成了嵌段型聚酯共聚物。利用石英微晶天平(QCM-D)检测己内酯/丙交酯聚酯薄膜在天然海水中频率和耗散的变化,并用POM、AFM和SEM原位观察了水解过程中薄膜表面微观结构的变化,初步推断聚酯共聚物的水解过程。     

Electrospun poly(vinyl alcohol)/permutite fibrous film loaded with cinnamaldehyde for active food packaging

Electrospun ultra‐fine poly(vinyl alcohol)/permutite fibrous film loaded with cinnamaldehyde essential oil was successfully fabricated.The morphology of fibrous filmswas characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM). The fibrous film exhibited microstructure features with high porosity with the pore size distributed ranging from 1.7 nm to 56.7 nm. And the root‐mean‐squared roughness of fibers lifted to 546.5 nm when the addition of cinnamaldehyde essential oil (CEO) reached 0.25 mL. Attenuated total reflectance‐fourier transform infrared (ATR‐FTIR) spectroscopyconfirmed the existence of CEO in fibrous films and revealed physical interaction rather than chemical interactions existing between the film matrix and CEO. Endothermic peaks presented in differential scanning calorimetry (DSC) profile were probably rooted from existed mesoporous adsorption between the highly porous film matrix and CEO. Furthermore, the PVA/permutite/CEO fibrous film prolonged the shelf life of strawberries, confirming that the PVA/permutite/CEO fibrous film may be of interest for the development of active food packaging. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46117.     

Localized Surface Plasmon Resonance Biosensing with Large Area of Gold Nanoholes Fabricated by Nanosphere Lithography

Localized surface plasmon resonance (LSPR) has been extensively studied as potential chemical and biological sensing platform due to its high sensitivity to local refractive index change induced by molecule adsorbate. Previous experiments have demonstrated the LSPR generated by gold nanoholes and its biosensing. Here, we realize large uniform area of nanoholes on scale of cm² on glass substrate by nanosphere lithography which is essential for mass production. The morphology of the nanoholes is characterized using scanning electron microscope and atomic force microscope. The LSPR sensitivity of the nanoholes to local refractive index is measured to be 36 nm/RIU. However, the chip has demonstrated high sensitivity and specificity in biosensing: bovine serum albumin adsorption is detected with LSPR peak redshift of 27 nm, and biotin-streptavidin immunoassay renders a LSPR redshift of 11 nm. This work forms a foundation toward the cost-effective, high-throughput, reliable and robust chip-based LSPR biosensor.     

Low-pressure assisted solution synthesis of CH3NH3PbI3-xClx perovskite solar cells

During the preparation of perovskite film, the common one-step method always generates an island-like structure. Large exposed areas lead to direct contact between positive and negative electrodes. Thus, the photoelectric performance is seriously deteriorated. Here, a low-pressure assisted method was introduced to fabricate dense halide perovskite films. The crystalline quality of the films was investigated by X-ray diffraction (XRD) spectroscopy. The film morphology and the device structure were characterized by atomic force microscope (AFM) and field emission scanning electron microscopy (FESEM). The effects of film quality on charge transport were discussed. After low-pressure treatment, the open-circuit voltage (V_oc), short-circuit photocurrent (J_sc), fill factor (FF) and power conversion efficiency (PCE) for the device were improved to 0.755?V, 20.045?mA?cm^?2, 0.52% and 7.9%, respectively. The optimized and centrally distributed performance parameters illustrate that the low-pressure assisted method can be used to improve the quality and uniformity of perovskite films.     

Synthesis of Fe2O3 nanoparticles for nitrogen dioxide gas sensing applications

Iron (III) oxide, Fe₂O₃, nanoparticles of approximately 40 nm diameter were synthesized by sol–gel method and their nitrogen dioxide adsorption and desorption kinetics were investigated by custom fabricated gas sensor unit. The morphology and crystal structure of Fe₂O₃ nanoparticles were studied by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) respectively. The roughness of film surface was investigated by atomic force microscopy (AFM). Relative sensitivity of Fe₂O₃ nanoparticles for NO₂ sensor was determined by electrical resistance measurements. Our reproducible experimental results show that Fe₂O₃ nanoparticles have a great potential for nitrogen dioxide sensing applications operating at a temperature of 200 °C.     

Flexible magnetoelectric PVDF–CoFe2O4 fiber films for self-powered energy harvesters

Integrating the concept of magnetoelectric in the mechanical energy harvesters through the magneto-mechano-electrical (MME) nanogenerators has been explored to realize the self-powered devices. The magnetoelectric interaction enabled the output performance of the MME nanogenerator under magnetic stimulus of the active components of the energy harvesters. In this perspective, we fabricated a flexible biomechanical and MME nanogenerator using PVDF/CoFe₂O₄ fibers composite films. CoFe₂O₄ fibers were synthesized by the electrospinning technique and the process parameters were optimized to achieve uniform and bead-free fibers. The structural and morphological properties were investigated through scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The structural and morphology revealed the fibers calcined at 800 °C with a heating rate of 2 °C/min produced bead-free continuous fibers with a fiber diameter of 210 nm with cubic spinel crystalline structure with a crystallite size of 34 nm. These highly crystalline fibers were used to fabricate PVDF/CoFe₂O₄ fibers composite films. The magnetoelectric behaviour of the films verified through polarization vs. electric field (P-E) loops under magnetic field. The leakage current density and mechanism of the composite films were investigated, and it was discovered that the mechanism was due to Schottky emission. Further the energy harvesting performance of the composite films were estimated where the nanogenerator achieved an output voltage of 13 V under biomechanical tapping force while the MME nanogenerator produced 3.5 V under a low frequency stray magnetic field of 6 Oe with a power density of 28 μW/m².