JOURNAL OF PHYSICAL CHEMISTRY B
·
2016
·
IF 3.187
Yihuang Chen,Tiansheng Gan,Chunfeng Ma,Linge Wang,Guangzhao Zhang
Crystallization of polymer chains confined on a surface greatly influences surface properties. We have grafted comb-like copolymer, consisting of poly(2-hydroxyethyl methacrylate) (PHEMA) backbone and semicrystalline poly(ε-caprolactone) (PCL) side chains, on silicon surface and investigated the crystallization of such confined PCL chains upon solvent evaporation by using atomic force microscopy (AFM), grazing incidence wide-angle X-ray scattering (GI-WAXS), and polarized optical microscope (POM). Our studies reveal that the PCL chains align and form “flat-on” lamellae at a low PCL chain density. As the chain density increases, the comb-like polymer (PHEMA-g-PCL) chains undergo pancake-to-mushroom-to-brush transition, and the lamellae turn from “flat-on” to “edge-on” in orientation. Further increasing PCL chain density leads the “edge-on” lamellae to change from a quasi-two-dimensional (quasi-2D) to quasi-three-dimensional (quasi-3D). Because of the confinements of polymer chains, we can observe the evolution of spherulites at different stages during the mushroom-to-brush transition of PHEMA-g-PCL chains. The confinements also result in knobbly substructures in the edge-on lamellae.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
International Journal of Nanomedicine
·
2023
·
IF 8
Dongmei Guo,Yue Huang,Kun Wang,Chenguang Yang,Lili Ma,Yu Zhang,Haiyang Yu,Manhua Cui,Zhaohui Tang
Purpose Cervical cancer (CC) is a highly vascularized tumor with abundant abnormal blood vessel, which could be targeted by therapeutic strategies. Poly(L-glutamic acid)-g-methoxy poly(ethylene glycol)/combretastatin A4 (CA4)/BLZ945 nanoparticles (CB-NPs) have shown great potential as nano vascular disrupting agents (VDAs) in the realm of synergistic cancer therapy.Methods In this study, we investigated the nanocharacteristics of CB-NPs, focusing on active pharmaceutical ingredients (API), as well as lyophilized samples combining API with protective agents (PAs). The in vivo efficacy of final sample (API + PAs) was evaluated.Results The assembled sphere of API with complex core and thin-shell structure was confirmed. PAs were found to significantly influence in vivo efficacy. Collaborative efforts between API and PAs, namely mannitol and lactose, resulted in the most promising lyophilized sample, ie, the final sample (FS2) for CC therapy. Impressively, FS2 demonstrated an exceptional 100% cure rate on the CC U14-bearing mice model.Conclusion FS2 has provided significant insights for cervical cancer therapy. It is also crucial to develop a comprehensive evaluation strategy for the formulation of nanomedicine, which has the potential to serve as a guideline for future clinical trials.
研究领域:
药剂学
·
肿瘤学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2025
·
IF 4.5
Bangdong Ge,Zongsheng Liu,Yi Zheng,Shiyang Zhu,Meng Ma,Si Chen,Yanqin Shi,Huiwen He,Yulu Zhu,Xu Wang
PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene) alloy has poor mechanical properties due to its poor compatibility and weak interfacial adhesion, which limits its application range. Therefore, it is necessary to compatibilize and modify the PC/ABS alloy to improve the compatibility and enhance the interfacial adhesion of the two phases. Reactive compatibilizers are frequently utilized to enhance the compatibility of incompatible polymer blends. However, traditional reactive compatibilizers often form graft copolymers with asymmetric molecular structure during melt blending, which frequently "migrate in" and "migrate out" under the influence of shear force, leading to a decrease in the compatibilization efficiency of compatibilizers. In this work, ethylene-maleic anhydride alternating copolymer (ZeMac) with more reactive sites was used as a reactive compatibilizer, and amino-terminated polystyrene (PS–NH 2 ) with good compatibility with ABS was synthesized via free radical polymerization. Combined with the difference of affinity between PC, ABS and ZeMac, and the difference of reactivity between PC, PS-NH 2 and ZeMac, a double-comb compatibilizer was constructed in-situ at the interface of the two phases by changing the blending sequence of raw materials in the melt blending process. Firstly, PC was blended with ZeMac, and then blended with ABS and PS-NH 2 to prepare (PC/ZeMac-1)/(ABS/PS-NH 2 -1) alloy with excellent comprehensive properties. Compared with PC/ABS alloy, the notched impact strength of (PC/ZeMac-1)/(ABS/PS-NH 2 -1) alloy increased from 62.0 kJ/m 2 to 90.2 kJ/m 2 , increased by 45 %. It can be seen from the microstructure of the cyclic tensile section that the debonding phenomenon of the PC/ABS alloy interface gradually weakened with the addition of ZeMac and PS-NH 2 , which proved that the compatibility of PC and ABS phases was improved. This study provides a certain reference value for the design of high-efficiency compatibilizers and the preparation of high-performance composites.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Energy Storage
·
2021
·Vol. 4
·期 2
·e289
·
IF 0
Peng Kong,Wei Zou,Zhongjie Du,Jingqian Deng,Chen Zhang
The comb-like polymers with crystalline aliphatic side chains are synthesized and then applied as the supporting material of phase change material. First, poly(styrene-co-acrylic acid) n -graft-octadecylamine (P(S-AA) n -C18, wherein “ n ” denoted AA feed ratio) is prepared. The crystalline behaviors of the comb-like polymer with different grafting densities are investigated. Then the paraffin@P(S-AA) n -C18 is obtained by packing paraffin into P(S-AA) n -C18. Attributed to the cocrystallization with paraffin, a form-stable phase change material (FSPCM) with high content of paraffin (≥90 wt% paraffin in FSPCMs without obvious leakage) and enhanced thermal property is obtained. The melting and freezing enthalpies of FSPCMs reach 124.4 and 126.3 J/g, respectively, which are higher than that of pure paraffin. And good thermal cycling stability and good thermal stability of FSPCMs are also exhibited. The result offers an avenue for developing the high-efficient thermal energy storage materials.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 11
·50040
·
IF 2.52
Shupeng Zhang,Lei Zhang,Xiaodong Yang,Wendong Hua,Junyun Qiu,Mingqian Zhang,Bo Zhang,Tianrui Ren
Coalescence and flocculation are two challenges for the stability and efficacy of pesticide suspension concentrate (SC) during the production and storage. To improve the stability of 25% pymetrozine SC, three comb-like poly(styrene-co-acrylic acid-co-polyethylene glycol methyl ether maleate) (SA-M) with different length side chains were synthesized by free radical polymerization and characterized by Fourier transform infrared spectroscopy and H-nuclear magnetic resonance. Surface-active parameters, including critical aggregation concentration (critical micelle concentration), saturation surface excess concentration ( Γ max ), minimum area per molecule ( A min ), and standard Gibbs free energy values were obtained from surface tension measurement. It shows that the surface-active property of SA-M decreased with the side chain length. Besides, 25% pymetrozine SC prepared using SA-M as dispersant had low zeta potential and low viscosity but high dispersibility and thermal storage stability. It is speculated that the formation of hydrogen bonds between nonionic branches and pymetrozine molecule at the expense of interruption of intermolecular hydrogen bonding between pymetrozine and water molecule, plays a key role in the stability mechanism.
研究领域:
农药科学
·
高分子化学
·
表面化学
✓ 已验证
DOI
高影响因子
PHARMACEUTICAL RESEARCH
·
2013
·Vol. 31
·期 2
·291-304
·
IF 4.742
Yang Xiao-Li,Luo Yan-Ling,Xu Feng,Chen Ya-Shao
Purpose Block copolymer micelles are extensively used as drug controlled release carriers, showing promising application prospects. The comb or brush copolymers are especially of great interest, whose densely-grafted side chains may be important for tuning the physicochemical properties and conformation in selective solvents, even in vitro drug release. The purpose of this work was to synthesize novel block copolymer combs via atom transfer radical polymerization, to evaluate its physicochemical features in solution, to improve drug release behavior and to enhance the bioavailablity, and to decrease cytotoxicity. Methods The physicochemical properties of the copolymer micelles were examined by modulating the composition and the molecular weights of the building blocks. A dialysis method was used to load hydrophobic camptothecin (CPT), and the CPT release and stability were detected by UV–vis spectroscopy and high-performance liquid chromatography, and the cytotoxicity was evaluated by MTT assays. Results The copolymers could self-assemble into well-defined spherical core-shell micelle aggregates in aqueous solution, and showed thermo-induced micellization behavior, and the critical micelle concentration was 2.96–27.64 mg L −1 . The micelles were narrow-size-distribution, with hydrodynamic diameters about 128–193 nm, depending on the chain length of methoxy polyethylene glycol (mPEG) blocks and poly(N-isopropylacrylamide) (PNIPAM) graft chains or/and compositional ratios of mPEG to PNIPAM. The copolymer micelles could stably and effectively load CPT but avoid toxicity and side-effects, and exhibited thermo-dependent controlled and targeted drug release behavior. Conclusions The copolymer micelles were safe, stable and effective, and could potentially be employed as CPT controlled release carriers.
研究领域:
材料科学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2025
·
IF 7.3
Minzhe Peng,Yajiang Huang
Non‑silicone release coatings, which are capable of reducing the adhesion force between adjacent surfaces, are widely used in fields such as electronics. Currently, they consist of mainly comb -like polymers with long alkyl side chains prepared via covalent grafting and usually require a large amount of organic solvents both during the synthesis and application process. In this study, a comb -like supramolecule (SGP) named PZS was synthesized in water via non-covalent grafting of stearic acid (SA) on polyvinyl alcohol (PVA) with ammonium zirconium carbonate (AZC) as the bridging agent. The effects of grafting amount on the microphase structure, crystallization properties, surface properties, and release performance of SGP were investigated. The release coatings prepared from the aqueous solution of SGP with an optimal molar ratio of [-OH] PVA : [Zr] AZC : [-COOH] SA = 2:1:2 were found to display a low peel strength (82.4 ± 16.8 N/m) comparable to that of covalently grafted ones. Most importantly, the newly developed PZS is waterborne and achieved nearly zero release of volatile organic compounds (VOCs) throughout their entire life cycle (i.e. synthesis and use stage). The newly developed waterborne SGP are promising release agent candidates that fulfill comprehensive industrial requirements of low peel strength, low cost, and environmental friendliness.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2024
·
IF 4.2
Jianan Guan,Xiao Liu,Shaojing Liu,Ruijun Gao,Ziming Wang,Suping Cui
A novel dispersant with ionic side chains (ISC-PCE) for cement slurries was elaborately designed and prepared by a simple two-step method and its molecular structure was proved. The performance test results showed that the cement paste containing ISC-PCE exhibited stronger fluidity retention (about 79.6 % after 3 h), longer free settling time (more than 3 h) and fewer flocculating structures, which presented significant dispersing stability. Furthermore, the working mechanism of ISC-PCE to cement particles was also probed via molecular conformation, adsorption, complexation ability, zeta potential and adsorbed layer measurements. It is interesting that the introduction of ionic side chains into conventional dispersant-polycarboxylate superplasticizer (PCE) molecules can achieve gentle and continuous adsorption and increase the adsorbed layer thickness (increased by 103.1 % compared to conventional PCE). The aim of this study is to offer a promising pathway to synthesize a novel PCE endowing outstanding workability stability and great rheological improvements to cement pastes by innovative molecular design. This PCE with ionic side chains has enormous promises as an effective substitute to conventional PCE with nonionic side chains, particularly in the cement paste systems with strict requirements on slump retention.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 41
·32853-32861
·
IF 3.84
Jintao Yang,Jiongzhou Zheng,Jingjing Zhang,Li Sun,Feng Chen,Ping Fan,Mingqiang Zhong
Poly(ionic liquid)s (PILs) with well-defined architectures have shown significant potential in various fields, but establishing an easy method for their synthesis remains a challenge. Herein, comb-like copolymers with polystyrene and PIL as backbones and side chains, respectively, were prepared by directly polymerizing ionic liquid monomer by atom transfer radical polymerization using poly(styrene-co-4-vinylbenzyl chloride) as macroinitiator. NMR, GPC, and FTIR were used to characterize the molecular weights and compositions of macroinitiators and resultant copolymers. Results demonstrated successful synthesis, and also indicated that graft density and side chain length of the comb-like copolymers can be readily controlled by tuning macroinitiator composition and polymerization time. DSC and EIS measurements were further performed to investigate the thermal and electrochemical properties of comb-like copolymers with various architectures. Both glass transition temperature and impedance were found to highly depend on structure, particularly on the graft density of side chains. Furthermore, these comb-like copolymers were used both as stabilizer to disperse reduced graphene oxide (RGO) nanoplatelets in organic solvent and as an additive for N2/CO2 separation membranes. As compared to neat PIL, a highly stable suspension of RGO in propylene carbonate and a composite membrane with enhanced N2/CO2 selectivity were obtained in the presence of comb-like copolymers. Given the many advantages of diverse compositions, multiple groups, and tunable structure of PILs, the comb-like copolymers show great promising in stabilizing carbon materials and membrane separation.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 99
·81482-81491
·
IF 3.84
Xuefei Leng,Zhiyong Wei,Yingying Ren,Yang Li,Yurong Wang,Qinyi Wang
In this work, two series of linear-comb and star-comb well defined graft poly(L-lactide) (PLLA) have been synthesized conveniently by one-pot ring-opening polymerization (ROP) of L-lactide using functionalized polybutadiene macroinitiators. The used organocatalyst of 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) allows the polymerization of L-lactide to proceed rapidly at room temperature. Kinetic studies of the ROP reaction in this system indicate first-order kinetics in monomer concentration. 1H NMR and GPC techniques are employed to characterize the synthesized polymers, validating the formation of the desired comb structures with controllable chain length. Linear-comb and star-comb graft PLLA were comparatively studied as well as with linear PLLA by DSC and POM. The results reveal that the comb structure gives a remarkable improvement of PLLA crystallization ability in both crystallinity and growth rate of spherulites. Furthermore, the more compacted star-comb structure imposes restriction on chain mobility, which weakens the growth effect to some extent. It is found that the glass transition temperature (Tg) and melting temperature (Tm) significantly depend on the side chain length and backbone structure. Rheological studies of both melt and instinct viscosity of the solution show that star-comb PLLA has the lowest hydrodynamic volume compared with linear-comb PLLA and linear PLLA.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2023
·
IF 5.5
Zhi Wei Fan,Xiao Lin Jin,Yang Chen,Mengze Lu,Yi Ru Wang,Kan Yue,Tao Wen,Liqun Tang,Zi Liang Wu,Taolin Sun
Strong adhesives as structural load-bearing materials can provide both adhesive bonding to substrate surfaces and cohesive bonding throughout the bulk material, which are widely used in the cement nail, electronic device, and automotive industries. By a molecular topological regulation, in this work, we developed a series of strong adhesives based on comb-like polymers. By systematically regulating the topological parameters including the side chain length, the spacer between side chains, and the degree of polymerization of the overall backbone, comprehensive studies on linear rheology (the terminal relaxation time and zero viscosity) and non-linear debonding adhesion (the work of adhesion) are performed on these comb-like polymers. It was found that the rheological behaviors depend not only on the structure parameters but also on whether or not the samples exhibit phase separation. Moreover, regardless of the topological structure of comb-like polymers with strong and weak phase separation, the universal work of adhesion is observed to be dependent on the multiplication of terminal relaxation time and the debonding rate, indicating dynamic control over the nonlinear work of adhesion. Furthermore, comb-like polymers are feasible to bind with diverse substrates, including glass, polypropylene and polyethylene terephthalate, wood, and metal. In comparison to existing works using dynamic physical or chemical bonds, molecular topology regulation is more easily fulfilled in strong adhesives without the use of additives and complicated chemical and physical modifications, lowering the barrier for practical applications.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·
IF 3
Ao Nan Lai,Shu Chun Li,Pei Zhi Zheng,Shu Feng Zhou,Shi Jie Wu
A well-designed architecture is presented here to construct high-performance anion exchange membranes (AEMs). A series of quaternized fluorene-containing block poly(arylene ether sulfone ketone)s (QFPESK-m-n) is synthesized as the main chains, and grafted with comb-shaped C8 long alkyl chains for the AEMs. By varying the hydrophilic segment’ length, there has been a significant change in the microstructure as well as phase separation morphology of the membranes, as confirmed by atomic force microscopy. Hence the as-prepared AEMs with moderate ion exchange capacities (IECs) show enhanced hydroxide conductivities in the range of 28.8―94.7 mS⋅cm −1 from 30 to 80°C. Furthermore, based on the block backbones and hydrophobic comb-shaped alkyl chains, the AEMs show low-level swelling ratios of 4.3% to 9.2% at 30°C and from 6.2% to 13.2% at 80°C, and superior ratios of conductivity to swelling. In addition, the QFPESK-m-n AEMs also depict acceptable mechanical properties, good thermal stability and an optimizable alkaline stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）