Search

Abstract As many manufacturing cities are currently experiencing serious environmental deterioration and energy crises, it is essential that they implement sustainable transitions by using cleaner production (CP) as a hopeful tool. We summarized the CP instruments applied in manufacturing cities and investigated their effect in urban sustainable transitions in this paper, by selecting Dongguan-a typical manufacturing hub in China-as a case. 264 related documents of policies, regulations, files, and notices promulgated by the Dongguan government during 2002–2017 were analyzed via content analysis to reveal the priority of major utilized tools for policy makers. We also summarized and analyzed the lifespan, dynamic trajectory, performance, function, and quantitative outcome of integrated CP instruments for sustainable transitions. It was found that CP instruments effectively decrease pollution generation, save energy, reduce resource consumption, and adjust and optimize industrial structure. It was also revealed that CP instruments embedded in sustainable transitions strategies was more effective and efficient at urban scale than that at larger scale. This paper provides a general reference for integrating CP instruments to push forward sustainable transitions in manufacturing cities, especially those cities without local legislative power in developing countries. Highlights • Content analysis were applied to analyze various cleaner production (CP) policies. • CP instruments effectively assists sustainable transition at urban scale. • Combining pollution prevention with energy conservation is effective strategies. • CP level and energy efficiency are useful indices for industrial structure optimization. • Continuity impacts the performance and outcome of CP policies. [ABSTRACT FROM AUTHOR]

[Display omitted] • The molecular weight and nanostructure size affected the replication quality. • High molecular weight polymers infiltrated into nanopores. • Polymer chains infiltrated to the bottom of nanopores under high pressure. • Progression of the entanglement of the polymer network was demonstrated. • Nanostructure size can facilitate interlocking by internal and interfacial friction. Understanding the effects of the molecular weight of the polymers and the pore size of the adherend surface on the mechanical interlocking of polymer/substrate interfaces is central for enhancing the corresponding adhesion strength. In the present study, we comprehensively investigated the effects of the molecular weight of polybutylene terephthalate and the nanostructure size on the replication quality by molecular dynamics simulations. Under practical pressures and temperatures, polymers of various molecular weights infiltrated to the bottom of the nanopores; the filling rate was > 90 %. The high filling rate and infiltration depth were attributable to the large external pressure (which can overcome the increased viscosity) and the semi-spherical nature of the nanopores (beneficial for polymer infiltration). The nanostructure size weakly corresponded to the filling rate and interfacial energy, but substantially affected the infiltration of the polymer chains. The entanglements of long-chain polymers remained during the filling and increased the joint strength, by enhancing the internal friction and the interfacial friction between the polymer and copper substrate. The current findings provide new insights into the effects of the nanostructure size and the molecular weight of the polymer on the replication quality of nanoinjection molding. [ABSTRACT FROM AUTHOR]

Noncooperative policies for transboundary pollution abatement are inefficient and ineffective, but cooperative policies for pollution abatement are seldom successful in regions that have different development goals and conflicting interests. In this paper, by extracting the key components that lead to the success of pollution reduction policies between Hong Kong (HK) and Guangdong, we aim to construct a general framework for cooperative environmental management. The incentive for and the dynamic trajectory, core measures, and outcomes of cooperative pollution abatement policies to address transboundary air pollution were studied using incrementalism analysis. The context that drives the abnormal increment of cooperative policies between HK and Guangdong was analyzed to determine the factors that affect the full cooperation process. The political union between HK and China is the main driving force for fostering cooperative policies in these two regions that have highly asymmetric economic development levels and pollution emission intensities. The factors for successfully designing cooperative pollution reduction policies are revealed from trust building, political support, efficient governance, precise policies, a rational cost-sharing mechanism, and detailed management and implementation plans. Innovative multi-level and cross-department governance, and an unequal but rational cost-sharing scheme sustain long-term cooperation. A general framework is derived from these empirical key components and constructed as a systematic approach to provide a guide for designing cooperation in transboundary pollution reduction for the sustainable management of cross-border natural resources in different regions with conflicts of interest. • An empirical framework of cooperative air pollution abatement model is constructed. • Factors contributing to foster cooperative polices is analyzed via incrementalism model. • Political support produces adequate institutional arrangements and precise policies. • A matching cost-sharing mechanism can catalyze and stabilize the cooperation model. • Multi-level and cross-department policies sustain long-term cooperation. [ABSTRACT FROM AUTHOR]

Whether foreign direct investment (FDI) damages the environment in host regions is an important question for both scholars and policy-makers. To examine the impact of FDI on a host region, Hong Kong-owned factories were selected as the providers of FDI and Guangdong was selected as the host region. The background, incentives, detailed implementation, and outcomes of the Hong Kong−Guangdong Cleaner Production Partnership Programme (CP3), a positive intervention by the home government (Hong Kong) using FDI to disseminate cleaner technologies for abating pollution in the host region (Guangdong), were comprehensively analyzed in this study. The successful implementation of the Hong Kong−Guangdong CP3 indicates that home governments can positively improve the environmental performance of FDI and make it cleaner. The spillover effects of cleaner technology dissemination from Hong Kong-owned factories benefit locally owned factories in related industries via different approaches. More importantly, the Hong Kong−Guangdong CP3 aims to achieve cleaner production in various industries, thereby creating a cleaner supply chain. Hence, a cleaner operations mechanism was gradually formed through the combined efforts of Hong Kong and Guangdong. Moreover, the reasons for the success of the Hong Kong−Guangdong CP3 were identified, and can be referred to by other regions. This study provides direct evidence to support pollution halo hypothesis that FDI from developed regions can promote cleaner development of host regions (developing regions) via a cleaner operations mechanism rather than heavily pollute host regions. Image 1 • The Cleaner Production Partnership Programme (CP3) between Guangdong and Hong Kong was introduced. • Cleaner production decreases the negative effect of foreign direct investment (FDI) at regional scale. • Cleaner technology dissemination from inward FDI benefited the local factories in Guangdong. • Cleaner supply chain management was implemented in Hong Kong-owned factories. • Cleaner operation of outward FDI in the case of CP3 supported Pollution hallo hypothesis. [ABSTRACT FROM AUTHOR]

Sustainable self-reinforcement organic filler, which does not contribute to environmental pollution, has been realized in the rubber industry as an alternative to modifying inorganic fillers with coupling agents or preparing rubber fillers, such as carbon black, with petrochemical products that cause environmental problems. In this work, tannic acid (TA), the world's third largest class of plant components that are easily available, is used as a self-reinforcing organic filler to prepare nitrile–butadiene rubber/TA (NBR/T) composites. Results show that TA can melt partially under vulcanization to assemble a weak interpenetrating polymer network (IPN) structure by hydrogen bonds under cooling, which is responsible for the dramatic increase in the mechanical and flexible properties of NBR/T composites even at low TA dosage. This finding provides a new perspective in preparing high-performance and sustainable rubber composites without sacrificing fossil fuels or non-renewable environmental resources. [ABSTRACT FROM AUTHOR]

The mechanical properties and the possible micro-structure of nitrile-butadiene rubber/lithium perchlorate/polyhedral oligomeric silsesquioxane (NBR/LiClO 4 /POSS) nanocomposites have been investigated thoroughly. The interactions among Li + cations, CN groups and C O C groups bring in a novel network structure consisting of several kinds of effective crosslinks, causing an increase in the glass transition temperature of POSS, as well as in the crosslink contribution ( G c ) and the constraint contribution ( G e ), which facilitates strong interface cohesion between POSS and NBR matrix and a well dispersion of POSS. The addition of POSS not only increases the crosslinking density of NBR/LiClO 4 /POSS nanocomposites, but also improves the 300% modulus and tensile strength greatly. Therefore, a possible micro-structure has been proposed to express the experimental observation. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the use of poly (ethylene oxide) (PEO) for in-situ modification of the inner surface of halloysite nanotubes (HNTs) with water molecules as the hydrogen bond forming medium, as well as the nano-confinement of PEO molecular chains within the nanotube. Before testing, the Soxhlet experiment of PEO/HNTs powder is applied in order to remove the physical adsorption of PEO molecules onto the outmost surface of HNTs. The crystal temperature of PEO changes sharply from 36.9 °C of neat PEO to −25 °C of PEO in the PEO/HNTs powder and the decomposed temperature of PEO in the PEO/HNTs powder is about 13.1 °C higher than that of neat PEO, which is mainly owing to the nano-confinement effect of PEO within the HNTs with a diameter of about 10 nm. From thermo-gravimetric (TG) analysis, about 7.71 % by weight of PEO has been chemically bonded to HNTs. The hydrogen bonds among PEO, HNTs, and water molecules are evidenced by FTIR and XPS performances. Meanwhile, the binding energy of Al2p in the innermost surface of HNTs shifts from 74.7 eV in the neat HNTs to 74.5 eV in the PEO/HNTs powder, while that of Si2p on the outmost surface of HNTs keeps almost constant, indicating that the hydrogen bonds only exists inner the nanotube and PEO molecular chains have been trapped in nano-scale within HNTs, which is in accordance with the DSC and TG observation. [ABSTRACT FROM AUTHOR]

Compatibility property, as well as crystalline morphology, of NBR/PEO blends has been investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized optical microscopy (POM) thoroughly. There is no apparent shift of nitrile or ether groups in the FTIR spectra of NBR/PEO blends. Based on the calculations from glass transition temperature, the maximum volume fraction of PEO dissolved in NBR phase is about 6.41 % in blend with 5 wt% PEO content (PEO-5), indicating a weak intermolecular interaction in the NBR/PEO blends. From the characteristic absorption bands in the FTIR spectra, XRD and POM graphs, the crystallinity ratio of NBR/PEO blends decreases as the NBR content increases, which is further proved by DSC measurement that the crystallinity ratio and crystal melting temperature of pure PEO are 82.6 %, 69.9 °C, and that of PEO-5 are 16.9 %, 59.5 °C. This illuminates that the weak intermolecular interaction will affect the crystallinity ratio and crystal melting temperature of the NBR/PEO blends. [ABSTRACT FROM AUTHOR]

It is still a challenge to prepare high performance rubber/MMT composites by one‐pot method without solution. In this work, NBR/AO60/montmorillonite (MMT) (NBR/AM) composites were prepared by mechanical blending method and in‐situ formation of surface hydrogen bond was introduced under vulcanization process. Results showed that the polar parts of melting AO60 could partly intercalate into interlayer of MMT and some parts of melting AO60 molecules were absorbed onto surfaces of MMT particles during the vulcanization process. Subsequently, surface hydrogen bonds were constructed among NBR, AO60, and MMT after natural cooling, as evidenced by FTIR, resulting in more complex morphology and good interfacial adhesion in the NBR/AM composite. Consequently, as compared to NBR/montmorillonite (NBR/M) composite, remarkable improvements were found in mechanical properties and energy dissipation at high temperature of NBR/AM composite, which may provide a new prospect for designing high performance damping materials. [ABSTRACT FROM AUTHOR]

It is demonstrated an effective to significantly improve the photocatalytic acitivity of BiOCl hierichial nanosheets by creating oxygen vacancies. These oxygen-deficient BiOCl nanosheets prepared via a two-step process exhibit substantially enhanced photocatalytic performance toward dye degradation when compared to the pristine BiOCl nanosheets. Such the superior photocatalytic performance is owing to the improved light-harvesting ability and increased doner density as a result of the induced oxygen vacancies. [ABSTRACT FROM AUTHOR]

The conflict between strength and toughness of plastic/rubber blends is still a great challenge in the world, especially for incompatible plastic/rubber blends. Here, we prepared carboxylated styrene-butadiene rubber latex (XSBR) and polyacrylamide (PAM) composites by a solution mixing method. FTIR and XPS results show a weak hydrogen bond between carboxyl groups of XSBR and amino groups of PAM, which is not enough to enhance the miscibility of XSBR and PAM. As a result, large parts of PAM precipitate to construct a macro continuous phase. A small part of PAM evolves from nanowires to a three-dimension nano network owing to the hydrogen bond inductive effect. Consequently, a leaf vein bionic nano-micro structure is proposed to interpret the great reinforcement effect in Young's modulus (112 times), tensile strength (almost 6 times) as compared to 5XSBR/5PAM with pure XSBR, which is almost equal to the mechanical properties of pure PAM. Meanwhile, the elongation at break and toughness of 5XSBR/5PAM is almost 1567% and 3370% of pure PAM, respectively. This may provide a new road to solve the conflict between strength and toughness. • A nano-macro structure is designed to solve conflicts between strength and toughness of immisicible plastic/rubber composites. • The XSBR/PAM composites possess ultra-high Young's modulus, tensile strength and toughness, as compared to XSBR or PAM. • A leaf vein bionic nano-micro structure is observed in the XSBR/PAM composites. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate a facile approach to synthesize high-performance and stable TiO 2 @PANI core-shell nanowires (NWs) as flexible electrodes for solid-state supercapacitors (SCs). The TiO 2 @PANI core-shell NWs are grown directly on highly conductive carbon cloth, which not only give efficient charge transport and accessible diffusion of the electrolyte, but also provide large surface area and active sites for redox reaction as well as good strain accommodation. Such these features enable them to deliver a large areal capacitance of 520.3 mF/cm 2 at 0.5 mA/cm 2 with outstanding rate capability. Furthermore, a flexible and stable solid-state SC device based on these TiO 2 @PANI core-shell NWs is also demonstrated. The as-fabricated solid-state SC device yields a remarkable volumetric capacitance of 898.4 mF/cm 3 , excellent flexibility and significant cycling stability with more than 97.2% retention of its capacitance after 10000 cycles. We believe that these findings may open up new opportunities to prepare high-performance PANI-based electrodes for flexible solid-state SCs. [ABSTRACT FROM AUTHOR]

Effect of molecular weight on conformation, helix structure (H structure) and trans planar structure (T structure), of Poly(ethylene oxide) (PEO) has been investigated in detail by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimeter. Two main diffraction peaks at about 2θ = 19° and 23° are discovered, and XRD patterns reveal that the unit cell of crystalline PEO belongs to the monoclinic lattice. The crystallinity decreases from 93.82 to 59.62 %, and the deviation of crystalline temperature of PEO-0.5 is larger than those of the other three under four reheated cycles. From FTIR results, a red shift about 11 cm is observed in the stretching vibration of -C-O-C- with increasing molecular weight, suggesting the presence of chain-chain interactions to restrict the stretching vibration of -C-O-C- in main chains. Meanwhile, the bending region of -C-C-O- at about 533 cm sensitive to tension shifts to lower wavenumber, and a new peak at about 510 cm emerges with increasing molecular weight, which is the indicator of internal tension/strain and orientation. Furthermore, the peak intensity ratios of H structure decrease with increasing molecular weight. In contrast, T structure increases dramatically. Consequently, with respect to molecular weight, the possible interactions, entanglements and tie molecules, of PEO molecular chains to explain the difference between H and T structure is proposed, which is in agreement with the experimental observations quite well. [ABSTRACT FROM AUTHOR]